The deep drawing process in metallic materials has several limitations such as the
stamped depth, appearance of wrinkles, fracture of the sheet before total
deformation, in addition to the fact that the solid generated varies in wall thickness.
Considering these variables, this work presents the study of the stampability of AISI
441 ferritic stainless steel under two initial conditions with the objective of evaluating
the effect of this variable on the stampability and mechanical resistance of this
material based on the calculation of the material's deformation limit (LDR ).
The mechanical characterization of AISI 441 steel used tensile tests (with
identification of anisotropy), Vickers microhardness and shear. The results indicated
the effect of the initial state of the material (as received and pre-deformed in cold
rolling) on the stampability limit of AISI 441 steel, being slightly higher for the as-
received state based on the comparison of the LDR value. It was also verified that
the predominant deformation mode in the stamped cups was stretching.
The stamping results associated with the anisotropy data indicated a change from
the preferred orientation according to the fiber  plane (111) to a more heterogeneous
one after stamping. In general, similar mechanical behavior was noticed between the
printed products for the two states analyzed in this work, consisting of softening at
the bottom and hardening on the side of the cups.

In this study we will discuss silicon steel applied in the diesel injection system, the so-called unit pump (UPS). In this system, for each cylinder of the engine there is a high-pressure pump, which is connected to its respective mechanical injector port. The fuel flow injected into the combustion chamber depends directly on the dosage of oil pumped by the unit pump, and this control is executed by the engine module, through the electronic control center (ECM). The purpose of this study is to develop a docking plate capable of replacing the original plate applied in these pumps. It is known that silicon steel plates are not manufactured in the required thickness, another point is that the plate needs to have adequate mechanical strength, appropriate magnetic properties and be an efficient and durable material meeting the needs of the end customer.

The relentless pursuit of energy efficiency has not only fostered advances in the field of industrial processes, but also the development of new materials. In the automotive segment, among the developed steels, the AHSS (Advanced High Straight Steel) stand out, which include steels that undergo phase transformation induced by plastic deformation, called TRIP effectc (Transformation Induced Plasticity) where it is possible to obtain high mechanical strength and ductility. The processing of this grade of steel, especially its welding, presents numerous challenges that require further study and understanding. In this context, one of the most promising alternatives involves the use of the friction spot welding process where there is conversion of kinetic energy into heat through friction between a non-consumable tool in rotary motion and the materials to be joined. As the solidus temperature of the materials is not reached, this union process develops in the solid state. Thus, this work aimed study welds on TRIP 800 steel sheets after induced transformation produced by the FSSW (Friction Stir Spot Welding) process. It investigated how the rotation speed and mixing time influence their microstructure and mechanical behavior. The data found showed that the weld microstructures were modified by the choice of configurations used and that the selection of low rotation values combined with lowers mixture times tend to have better performance with the delivery of a greater tensile strength e and greater elongation when this was applied to exercises until its break.

Literature has recently described that the interaction between an implant and bone tissue is due to a combination of ultrastructural factors, such as morphology and the surface chemical composition of the device to be implanted. The long history of success of titanium and its alloys in implant dentistry reinforces that under conditions of control of passivation, the surface has a natural film of thickness varying from 1.5 to 10nm, composed of titanium dioxide (TiO2) capable of provoking a biological response more favorable. In this work, the surface of the Ti6Al4V alloy will be optimized through an electrochemical anodization process. This process aims to change the morphology of the titanium dioxide (TiO2) layer in order to increase its tribochemical behavior and biocompatibility. The effect of processing parameters on film characteristics will be evaluated, such as film thickness (TiO2), abrasive wear coefficient, microhardness and roughness. In this way, the aim is to provide better biofixation of the biomaterial to the bone tissue. Through the anodization process, a thin TiO2 film was produced, with nanotubular characteristics (TNT) to be analyzed regarding morphological, physical, tribological and biological aspects. In this anodization process, TNTs will be produced from anodization with an electrolyte of C6H8O7 (0.1 mol/L) + NaF (0.5% w/w), application of DDP at 20 V DC, for 90 minutes. The morphological and chemical characterization to be carried out will involve Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM/EDS), X-ray Diffraction (XRD) and X-ray Fluorescence (XRF). The characterization of the biomaterial may determine the combination of process variables that will positively modify the film formed and enable greater reliability for electrochemically coated products.

Magnetite nanoparticles (Fe3O4) have received enormous attention from the scientific community due to their wide range of applications. This mineral has an inverse cubic spinel structure, generating special properties that are in demand for medical, pharmaceutical, and therapeutic applications. In addition, it can be synthesized in the laboratory using for example the chemical route, where nanoparticles are formed from base elements, such as Fe, followed by a nucleation and growth process. In the next step, functionalization of its surface can be done using some polymers, metals, organic and inorganic molecules aiming to expand its application. This modification favors the application of the nanoparticle in the process of drug release, for cancer treatment. For the synthesis for biomedical purposes to be successful, it is necessary that no agglomerates of nanoparticles are formed during the synthesis, so that when used in humans it does not cause any organ damage. Its diameter should be small in the order of nanometers, with a narrow size distribution and monodisperse. For this reason, the investigation of production techniques is extremely important for the control and efficiency in which these nanoparticles are synthesized in order to obtain the desired properties. In order to study the structure, morphology, and magnetic properties, different chemical routes were used by comparing their respective characterizations. Samples were synthesized by reverse micelle microemulsion with SiO2 coating, and also by coprecipitation, one without coating and one with oleic acid coating. Microstructural analysis and physical characterization, X-ray diffraction with Rietveld refinement, transmission electron microscopy, and mathematical calculation using the Scherrer equation were performed to define the particle size. From the microstructural analysis and calculations presented in this work, it was obtained: i) the synthesis of Np was successfully performed and the particles are single-phase and constitute perfect polyhedra ii) the SiO2 coating was successfully performed, its particles are monodisperse, iii) the diameter sizes draw attention to the SiO2-coated nanoparticle DSiO2=18.09nm, Dpura=8.02nm, and DOA =7.82nm iv) the distance between oxygen and Fetet ions: d1SiO2=1.80Å, d1pura=1.98Å and d1OA=1.91Å, v) the distances between oxygen and Feoct ions: d2SiO2=2.10Å, d2pura=1.99Å and d2OA=2.04Å, and vi) the angles corresponding to the Fetet-O-Feoct bonds: φSiO2:125.60°, φpura:121.36° and φAO:123.08° which then indicates that these constitute perfect polyhedra with high symmetry. The AC susceptibility measurements obtained by fitting showed relaxation time values τ0=2.72.10-10 for Fe3O4@Pura and τ0=8.72.10-6 Fe3O4@SiO2, which indicate a super spin glass type behavior. SAR tests pointed out that the synthesized nanoparticles showed temperature rise befitting magnetic hyperthermia applications when subjected to a magnetic field, an indication that the tested nanostructures are viable for magnetic hyperthermia applications

The search for processes that provide improvements in the surface qualities of metallic materials is a constant among researchers in materials science and engineering, especially in relation to wear resistance of components. In this context, the present work intends to investigate the viability of the ionic implantation of boron atoms in metallic surfaces through the process of electrolytic plasma boriding by machining by electrical discharges by penetration. The material used was AISI 4140 steel and the procedure applied in an adapted EDM machine. Electrolytic copper were used as tool electrodes.  The boron source were aqueous solution of sodium octaborate diluted in deionized water,. As a result, it was possible to observe the formation of the borid layer by optical microscopy and the Vickers microhardness test, with gain of 146.8% in hardness value in relation to the base material. The presence of boron was detected by x-ray diffraction.

AISI H13 and AISI P20 steels are widely used mainly in the machining and tooling
industry for the manufacture of plastic injection and blow molds and aluminum injection
because they present satisfactory performance in hot work. The high hardness and
complex geometry of some of these mold components make it impossible or
impossible to manufacture them by machining processes with a cutting tool with a
defined geometry, such as turning, milling and drilling processes. But even with the
aforementioned peculiarities, if these components are electrical conductors, they can
still be machined by Electrical Discharge Machining (EDM). Many of these components
before final use require hardening heat treatments such as quenching, carburizing,
nitriding and boriding. Therefore, this work presents a study of the possibility of Boring
with surface hardening in AISI H13 and AISI P20 steels together with Electrical
Discharge Machining (EDM). Steel samples were subjected to (EDM) using electrolytic
copper electrodes. In place of the conventional dielectric, a solution of Sodium
Octaborate Tetrahydrate diluted in deionized water was used as a source of boron to
verify the possible formation of a boride layer. As a partial result a hardened layer of
approximately 30μm thickness was observed on AISI H13 steel and 35μm on AISI P20
steel using Optical Microscopic (OM) and Scanning Electron Microscopic (SEM). To
verify a possible presence of boron in the layer formed of each material, the samples
were subjected to the characterization technique by X-Ray Diffraction (XRD) where
spectra with peaks at specific diffraction angles that predict the existence of the
element Boron were observed in both materials. (B) in the layer when these spectra
are compared to the same materials AISI H13 and AISI P20 submitted to traditional
boridations already based in the literature. In the hardness test, 649HV was obtained
in the boride layer for the H13 steel, which represents a gain of 146% compared to the
untreated base material and 694HV for the AISI P20 steel, representing a gain of
159%.

Chitosan is a bio-polymer obtained by the deacetylation reaction from chitin, a natural polymer found in the exoskeleton of crustaceans, and widely bio-available due to the high volume of crustacean shells annually discarded by the fishing industry. Additionally, chitosan has a structure rich in oxygenated and nitrogenous functional groups that are potentially useful to promote its interaction with the metallic surface of steels, and it is also a polymer soluble in acidic media. Given the chemical characteristics of chitosan and its relatively low cost and high availability, the present research project evaluated the potential of chitosan as an environmentally friendly corrosion inhibitor for 304 stainless steels in hydrochloric acid (HCl) medium. Different electrochemical tests was carried out in HCl medium in the absence and presence of chitosan at various concentration levels to obtain the electrochemical parameters related to the corrosion of 304 stainless steel, such as corrosion potentials, corrosion current densities, inhibition rates, Tafel slopes, polarization resistances and charge transfer resistances. To this end, the tests carried out consist of open-circuit potential (OCP) measurements, potentiodynamic polarization curves and electrochemical impedance spectroscopy, using properly cut and prepared specimens. In addition, the morphological and chemical characterization of the surface of the specimens carried out before and after contact with the different corrosive media using scanning electron microscopy, energy dispersion X-ray spectroscopy (EDX) and Raman spectroscopy. Based on the electrochemical and characterization results, it was concluded that chitosan was effective in inhibiting acid corrosion of 304 steel.

Boriding is a thermochemical treatment used in steels to improve their surface properties, promoting better performance in various tribological applications in mechanical engineering. This research work investigated the feasibility of using sodium octaborate (Na₂B₈O₁₃.4H₂O) as a source of the element boron in the process EDM, by penetration, in AISI 8620 steel surface, using an adapted EDM machine. The tool electrode used was electrolytic copper. Sodium octaborate was diluted with deionized water to form the aqueous solution, which acted as a dielectric fluid. The boride layers was evaluated by optical microscopy and Vickers microhardness test. Boron diffusion was evaluated by x-ray diffraction on the machined surface and by energy dispersion x-ray spectroscopy (EDS) in Scanning Electron Microscopy (SEM) equipment. After the application of the EDM process, a gain of 134% was verified, approximately, in the hardness value of the boride layers in relation to the base material. The FeB and Fe₂B phases were detected in the X-ray diffractograms, as well as the diffusion of the boron element observed by means of EDS in the cross section of the piece close to the surface.

Pre-construction paints, also known as shop primers, are used in several industrial segments in order to prevent oxidation during the processing steps. As welding operations are carried out over coated plates, there is concern about the negative impact of the paint on the welds. In this sense, despite the countless efforts in order to minimize undesirable consequences, there is still a vast investigative field involving welding consumables and, mainly, the formulation of paint. This work aims to verify the influence of shop primer lithium fluoride addition in the welding process (electrical parameters and weld characteristics). In order to verify the influence of fluoride, the results were compared between samples without coating and coated without, with 10% w / w and with a load of 20% w / m of fluoride. The results showed a relation between shop primer and fluoride addition on the electrical signals and weld bead morphology.

The petrochemical industry, especially oil refineries, contains a wide variety of aggressive environments, some of which are unique to this sector. For example, corrosion by ammonium chloride, a salt formed in the processing of gasoline and diesel hydrotreatment, interfering with the operation of the industrial plant, damaging the mechanical and/or metallurgical characteristics of the materials, with operational, financial, and even life-threatening repercussions. In this research, potentiodynamic polarization and electrochemical impedance spectroscopy were used to determine the corrosion resistance of three different austenitic stainless steels, AISI 304, AISI 316L and AISI 317L, exposed to a saline solution of sodium chloride (NaCl) and ammonium chloride (NH₄Cl), both at 3.5% (w/v) concentration. The results indicated that the 317L austenitic stainless-steel samples presented larger passivation regions, with higher pitting corrosion potential and lower passivation current density values, and lower corrosion rate values.  They also presented higher values of real and complex impedance for all the frequency spectra analyzed, in addition to the presence of unique semicircles of inductive characteristic. Thus, the comparison of corrosion resistance showed to be the austenitic stainless steel 317L which conferred greater corrosion resistance among the steels adopted in this research. In sequence, in the capacity of resistance to corrosion, we have the stainless steels 316L and 304, immersed in the analyzed electrochemical means. The formation of pitting corrosion was more prevalent in the ammonium chloride medium for the 316L and 304 stainless steels. Therefore, the application of these steels in environments containing this salt is not recommended, mainly, in the reaction sections of petroleum products hydrotreatment units.

Electric steels are a special type of steel, with great importance in the steel industry. These steels are largely applied in motors and transformers, being widely consumed due to magnetism presenting itself as an efficient way of transforming electricity into mechanical movement. Two families of electrical steels stand out, the GOs (grain oriented) and the NOs (non-oriented). In this study, two semi-processed non-oriented electrical steels, one with a Fe-Si base and the other with a Fe-Al base, were investigated for magnetic losses and mechanical properties, in the conditions as received and after heat treatment. The microstructural aspects were obtained via optical microscopy and scanning electron microscopy supported by EBSD technique. The mechanical properties were evaluated by tensile and hardness tests. The magnetic properties, such as saturation magnetization, permeability and loss components (parasitic, hysteretic and excess) were obtained over a wide frequency range (10–400Hz/10–60Hz) and maximum polarization (0.1– 1.5T), through the Epstein test, by equipment manufactured by Brockhaus. The average grain size of the Fe-Si-based sample after heat treatment was approximately 68μm, while the Fe-Al sample was 128μm. In the analysis of inclusions, the material based on Fe-Si showed better results, with an inclusion density of 68.5 inclusions/mm2, against a density of 102.3 inclusions/mm2 of the Fe-Al sample. In mechanical properties, the heat treatment led to a decrease in yield strength and strength values, results that improve the stampability of the blades after cutting. Comparing the two steels, the Fe-Si steel showed a higher hardness value, due to the higher carbon content present in the sample. The different results obtained were reflected in the magnetic properties, both in the evaluation of the loss components separately and in the total losses, with the Fe-Si sample presenting bigger losses at frequencies up to 200Hz, and above this value, the biggest losses went from the sample to Fe-Al. Based on the results, it was possible to establish important discussions on the microstructural aspects and chemical composition on the mechanical and magnetic properties.

Thin films, with thickness on the nanometer or micrometer scale, have been used in several areas of science and technology, as these coatings give the substrate different optical, chemical, electrical, mechanical, magnetic or thermal properties. To obtain the thin films, the precursor materials can be liquid, solid or gaseous, and the choice of the deposition technique takes into account, especially the physical state of the precursor material. The sol-gel method stands out for the preparation of thin films in the liquid state. With the intention of modifying or improving the substrate properties, many types of materials can be deposited from ceramic to metallic materials. The choice of material should mainly consider its application, properties and availability of access. In recent years, an exponential growth has been observed in the scientific study of the properties and applications of titanium dioxide (TiO₂). TiO₂ has interesting properties for use in coating metallic substrates to prevent the corrosion process and self-cleaning character that is related to its oxidative potential by the incidence of ultraviolet light. Due to its crystalline structures it is possible to combine TiO₂ with other compounds to improve its properties. In this sense, the insertion of niobium ions (Nbⁿ⁺) in the TiO₂ structure can bring promising results for the industries of the branch. Believing in the corrosion preventive potential of thin films with TiO2/Nbⁿ⁺ and knowing that the wear of metallic materials costs countries, on average, 5% of the PIB value, the present work aims to evaluate the potential of the film nanostructured based on titanium dioxide and niobium to prevent corrosion of AISI304 stainless steel in acidic media containing chloride ions. The film was obtained by the sol-gel method using titanium isopropoxide (IPT) in acetylacetone (AcAc) as precursors; ammoniacal niobium oxalate (ONA) in methanol. Nitric acid was added to reach pH=2 while the system was under agitation. The deposition of the film on the AISI304 steel took place by the immersion method (dipcoating) and then the samples were subjected to heat treatment up to 550°C. Structural and morphological analyzes were performed. To evaluate corrosion, the samples were submitted to an electrochemical test in 2mol/L HCl solution. Previous DRX results on the particulate material reveal that the crystalline phase is anatase and the peak shifts indicate the insertion of niobium in the TiO₂ matrix. Optical microscopes and MEV reveal the homogeneous adhesion of the film on the metallic substrate.

The lattice structure is the study object for application in tissue engineering, as it presents high mechanical performance, high capacity to absorb energy and low density of this structural arrangement. The most recent possibility of manufacturing the lattice model is through advanced additive manufacturing techniques, which print complex structures with dimensional accuracy, speed and simplicity. The most widely used additive manufacturing technique nowadays is fused deposition modeling (FDM), which has advantages such as a simplified approach, dimensional efficiency and economically viable devices. However, the FDM technique includes several process parameters that directly affect the quality and properties of the printed parts. Therefore, studies are necessary to minimize or eliminate usual problems to FDM, such as anisotropy, high processing time, inferior mechanical properties, voids and lack of adhesion between the printed layers. In this work, it is proposed to manufacturing lattice structures with high porosity, which will be obtained through the FDM printing technique, with emphasis on the parameterization of the main process variables related to the analysis of the rheological behavior of the material, aiming to contribute to the improvement techniques for making scaffolds. Structures will be printed in poly(lactic acid) (PLA) and subsequently adsorbed magnetic nanoparticles on the scaffold structure. At the same time, structures will be printed with a blend with self-healing properties composed of poly(ethylene glycol-co-cyclohexane-1,4-dimethanol terephthalate) (PETG) and Surlyn 8940®, a poly(sodium ion stabilized methacrylic acid co-acid) (PE-co-AMA), which allows the reduction of printing defects. The printed samples will be characterized mechanically, thermally, structurally, morphologically and rheologically. Keywords: lattice

The grain-oriented silicon steel, HGO, is employed in magnetic cores of electrical machines due to its favorable electrical and magnetic properties, such as high permeability, high electrical resistivity, low coercive field, and low energy losses. Electrical steels play a vital role in today's energy sectors. To prevent sticking between silicon steel sheets during the high-temperature annealing process and to reduce total energy losses, a primary layer of forsterite (Mg2SiO4) or glass film is formed. To enhance the insulating property and corrosion resistance of silicon steel, an insulating coating is added over the forsterite. It is evident that one key approach to improving the characteristics of grain-oriented electrical steel involves applying an electrical insulating coating, phosphate-based, on the glass film surface. This results in the generation of tensile elastic forces in the metal, consequently reducing energy expended in a magnetization cycle. The aim of this study is to evaluate the effect of the phosphate component of the insulating coating on magnetic losses in grain-oriented electrical steels. The phosphate density on HGO steel ranged from 0.005 to 0.006 Kg/mm2, and the average tensile stresses induced by the component in the metal ranged from 3.67 to 7.03 GPa, depending on the coating. Magnetic induction passage varied with coating presence, with uncoated steel exhibiting the highest permeability. At 50 Hz, the percentage difference in total losses between coated and uncoated steel was explained by non-uniformity in magnetic induction levels. The secondary coating reduced magnetic losses by 1.7/50, ranging from 0.988 W/kg to 1.199 W/kg. Using the phenomenological loss separation model, Ph, Pa, and Pc were calculated, with samples lacking secondary coating showing higher Pa values from 20Hz onwards. At 1.7 T/50 Hz, Ph losses increased by 6.5%, Pc losses remained constant at 1%, and Pa losses increased by 6.3%. Below 20Hz, Ph surpassed Pa and Pc, with an inversion occurring above this threshold, where Pa became greater than the other two components across the frequency range.

The Alkali-Aggregate Reaction (AAR) is a pathology related to concrete that occurs due to the existence of three factors: the presence of alkaline oxides, usually sodium or potassium, from cement, reactive minerals found in some types of aggregates, and moisture. Supplemental cementitious materials (MCS) are considered suitable inhibitors for AAR and are also contributors to studies of new materials that help reduce clinker and help advance sustainability. Alkali-activated materials (MAA) are made from the alkaline activation of solid aluminosilicates. Raw materials can vary in origin and composition, making room for waste and by-products on a large scale and in low demand. The method used to investigate the RAA was the accelerated test of mortar bars established by NBR 15577 (ABNT, 2018). The granulometric curve of the aggregate used, basalt stone powder, was obtained by sieving e. The chemical, mineralogical and microstructural characteristics of the aggregate were analyzed using X-ray fluorescence (FRX) and ray diffraction (DRX) and scanning electron microscopy (SEM) tests. The expansion of prismatic bars (25x25x285mm³) produced with CP-V cement, aggregate, and water was analyzed. The bars were cured for 30 days in a thermal tank at 80º C in water and NaOH and presented expansions of up to 0.63%, indicating high reactivity of the basalt. Different formulations of MAA mortars were produced with an aggregate/precursor ratio of 2.25 and activator/precursor 0.6. The precursors used are metakaolin (MC), granulated blast furnace slag (EGAF), and sugarcane bagasse ash (CBCA). The activator solution is composed of 8M NaOH and sodium silicate (SS). The MAA mortar bars were stored separately in water and NaOH solution and will be analyzed for RAA under both conditions. After 30 days of accelerated curing, the bars will be subjected to a flexural strength test. In order to investigate whether there were differences in the properties of mortars cured in water and NaOH, the same samples will be investigated. The remaining parts of the rupture in the bending test will be sawn into perfect cubes and characterized for compressive strength, water absorption, and microstructure.

Every ten seconds humans kill approximately 24,000 animals for food, up to 75 billion a year. A task that is accomplished with speed and efficiency like never before in the history of mankind. While the world's population has more than doubled in the last 50 years, meat production for consumption has more than quadrupled. The land, water, food and greenhouse gas emissions involved in this production are reaching frightening values. Laboratory meat production (farmed meat), a science that has emerged in the last decade, presents itself as a possible solution to the problems involved in raising animals for slaughter. Still young, this branch of science still needs a great deal of study and parameter setting to become an industry with productive capacity on a global level. One of the most important aspects for laboratory animal protein cultivation is the bias in the development of porous scaffolds to promote the mechanical support that cells require. Electrospinning is one of the most applied techniques for the fabrication of these structures, but it has a low production rate, which directly implies the cost of the final product. In this work we will study the manufacture of two equipment inspired by the technique of Rotary Jet Spinning (RJS), a promising alternative to overcome the challenge of producing scaffolds to meet an imminent global demand. Cellulose acetate (Sigma Aldritch) nanofibers will be made with bixa orellana extract added (1%wt) by both techniques, thus, the morphological, chemical, physical, mechanical and biological properties will be compared in order to determine the advantages and disadvantages outlined by the nanofibers produced.

Tissue engineering is seen as a promising solution for the reestablishment of the normal functions of the organism, as it explores the concept of reconstruction and regeneration of tissues and organs in the laboratory through the in vitro culture of patient cells on biodegradable biomaterials, the scaffolds and, therefore, are reinserted into the patient. Currently there are several methodologies and materials for the production of scaffolds, an affordable and large scale approach is still a challenge. Among the scaffold production methodologies, the techniques of decellularization applied to fruits and legumes have shown to be very promising. The vegetables are interesting because they are basically constituted of cellulose which is a biocompatible and biodegradable polymer, and yet exhibit an interconnected pore structure of the extracellular matrix that can act as scaffold for the culture of mammalian cells. In the present project it is proposed to obtain low cost scaffolds from plant decellularization. The decellularization methodology will be developed in order to maintain the morphology and mechanical properties of the plant matrix. The material obtained will be characterized by Fourrier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric analysis (TG-DTA) differential scanning calorimetry (DSC).

The proposed work consists of an innovative process of laminating carbon fiber in a female mold cavity for the production of hollow parts by blowing air under controlled pressure conditions. The scientific investigation is about the influence of temperature and pressure on the compacting of the fiber layers, the interface between the fiber and the polymer matrix, and its resulting consequences on the mechanical strength of these parts. Also will be studied the counter internal mold that will receive the air conditioning, inflate and press the fibers against the walls of the mold.
The work will be developed in pieces of simple geometry, in this case a tube of rectangular section, but the acquired knowledge can be used in pieces of complex geometries like bicycle frames, tennis rackets, wings and fuselages of airplanes, wind blades as well as others parts for the aerospace sector and for the automotive / automotive market. The aviation industry, sports equipment manufacturers and the increasing use of electric cars stimulate the development of cost-effective carbon fiber lamination processes and can be used to manufacture hollow parts with complex geometries.
The main difference of the proposed process for the conventional ones employed in the industry is to eliminate the most costly part of the process, the autoclave, causing the mold itself to perform the autoclave function for application of pressure and temperature for curing the resin and compacting the layers of fiber and consequently ensure high mechanical strength that will be verified by tensile and bending tests.

In order to analyze and validate the energy efficiency of the EOF (Energy Optimized Furnace) primary refining furnace, we propose in this study an analysis by computational modeling of the gas flow and the resulting thermal use. After researching in specialized literature, all the mathematical models already validated for computational modeling and to support the reading and interpretation of the obtained results were raised. Throughout this study, the structure of the EOF furnace, the furnace operation cycle, the types of metal scrap used and the thermal losses with the walls composed of refrigerated elements were evaluated. Through the computational model, the gas flow was analyzed and it was verified that the current kiln works with an atmospheric air inlet greater than the ideal and the real density of the metallic scrap different from the design density, which caused a great loss in the kiln's energy efficiency and the limitation of productivity gains in the process. After these validations, a working scrap density is proposed for better efficiency of the EOF furnace process.

The study of multiphase flow is present in the processing of one of the most used materials in the world, steel. In the melt shop, steel processing occurs in some stages within the steelmaking models, from primary refining, through secondary refining to continuous casting or conventional casting, composed of equipment called reactors. The study of steel refining reactors to control the surface and internal quality of the final product, is one of the interests in the steel industry, in order to guarantee the quality of the steel and increase productivity. In the continuous casting process, in the melt shop, one of the equipment is the tundish. In the first continuous casting processes, the tundish had only the function of reservoir of liquid steel, between the pan and the mold, where he distributed the steel between the veins and to have a better operational control, being able to develop mathematical and physical models. After great development in the steel industry, the tundish started to perform other functions besides the steel distribution, such as the improvement in the steel's clarity. One of the mechanisms used for this improvement in the tundish is the argon diffuser. This mechanism occurs through an inert gas curtain with the ability to float inclusions, endogenous and / or exogenous classifications. This gas injection generated a need to model the tundish reactor as multiphase. In addition to the gas injection, it was necessary to understand the behavior of the slag towards liquid steel, and there may be a phase of the steel / slag mixture. Some points can be discussed in multiphase flow mathematical models, such as the definition of velocity profiles to characterize a dead or stagnant volume, and algebraic models to simulate the removal of inclusions, such as alumina and silica within the steel. A low-cost way for industries to study a reactor's process and geometry variables is computational mathematical modeling. Computational Fluid Dynamics or CFD; is the area of knowledge that deals with the numerical simulation of fluid flows, mass transfer. The present work will use computational mathematical modeling to simulate a physical model of a tundish, installed in the company USIMINAS, in order to propose a definition of the characterization of stagnant or “dead” volume, and verify the assertiveness, through validation with the data of the physical model, using Computational Fluid Dynamics techniques.

This research aims to study the feasibility of applying the residue generated in the foundry process of aluminum scrap, known as sludge, as raw material in the production of geopolymeric materials, because previous studies indicate that the reject of Aluminum has relevant alumina and silica content. This residue is a toxic material, so it is necessary to be disposed of in appropriate landfills to avoid damage to the environment, which leads to the importance of giving new applications to this reject. Geopolymers are materials obtained by alkaline activation of aluminosilicates and have several applications, and can be used in substitution to Portland cement, may also be applied in the industry, which is used as thermal insulator, for Example. The geopolymers have great sustainable potential and can have their matrices produced with up to 100% of residues containing SiO2 and Al2O3. The Reject, after being removed from the furnace The Crucible will be grinded, sifted, and characterized by X-ray diffraction, to analyze the crystalline phases present, X-ray fluorescence, to analyze its chemical composition, and will also be analyzed by microscopy Scanning electron (SEM), to study the topography and microstructure of the aluminum dross. As a source of silica, Metacaulim will be used. The carbon powder will be added as aggregate to confer mechanical resistance to the material. To improve the performance of the Geopolymer as thermal insulator, will be placed in the mixture the aluminum powder, which acts as a pore forming agent. An evaluation of the performance of the carbon powder and its ideal content to improve the mechanical strength of the Geopolymer, the content of the aluminum powder will also be evaluated. The curing temperature of the materials will be studied, the temperatures analyzed will be 40, 60 and 70 ° C. The alkaline activators used in geopolymerization are sodium hydroxide (NaOH) and sodium silicate (Na2SiO3). Some samples of the formed Geopolymers will undergo heat treatment at the temperature of 1000 º C, these samples shall be characterized by X ray diffraction to analyze the effects of heat treatment on the possible formation of new crystalline phases. The Geopolymer samples will undergo bending and hardness tests to evaluate the mechanical behavior of the material. The geopolymeric matrices will also undergo thermal conductivity tests, thermogravimetric analysis and adsorption assays using the BET method (Brauner, Emmett, Teller) for porosity evaluation. In this way it will be possible to indicate applications for the reject, which can reduce the environmental impacts generated by aluminum foundries, the reject gains economic potential and the society will have a cheaper, functional and sustainable product option. 

One of the main concerns of the mining industry is the large amount of waste generated in mineral extraction and processing. In addition to causing impacts on the environment, these environmental liabilities occupy large areas and can cause problems in their disposal. The use of such residues in civil construction has been promising through several researches. This dissertation seeks to incorporate sterile from phosphate mine in the production of hydraulic tiles in partial replacement to Portland cement. The waste was characterized by means of granulometric analysis tests, scanning electron microscopy (SEM), X-ray fluorescence (XRF), X-ray diffraction (XRD), thermogravimetric analysis (TG) and evaluation of pozzolanic activity. The hydraulic tiles was produced by replacing cement with waste in the content of 25%. The pieces were produced with the waste without calcining and calcined at temperatures of 400°C and 600°C. The tiles were evaluated according to some parameters such as visual and dimensional analysis, water absorption, color uniformity and mechanical resistance. As a result of the work, it was possible to obtain pigmented hydraulic tiles by using the waste with reduced Portland cement consumption, satisfactory strength and aesthetically appropriate.

The literature has shown that recent developments of new nanocomposites can show improvements with comparative advantages in mechanical, thermal and/or tribochemical properties, giving them technical and economic feasibility for use in the civil construction industry. One of the potential applications would be the microstructural and physicochemical optimization of epoxy polymer matrix composites reinforced with glass fiber for making GFRP (Glass Fiber Reinforced Polymer) rebars and/or, in particular, in nanocomposites of this same matrix reinforced with nanotubes and/or graphenes. In addition, steel is today one of the most used materials in civil construction, having a very satisfactory mechanical performance, however, its main disadvantage is its susceptibility to corrosion/erosion, affecting its structural integrity, reducing the useful life in service or durability of concrete reinforced, mainly by the accumulation of humidity, sea water or by phenomena such as acid rain. Thus, the combination of this type of nanocomposite using fiberglass and graphene can represent a considerable increase in its properties. In this work, specimens of GFRP rebar were made from 5 different compositions: 2 composites of epoxy matrix/glass fibers 50:50 m/m with oriented fibers (rover) and the other with chopped fibers (FVP), and 3 other variations graphene nanocomposites (with 0.30%, 0.50% and 0.70% w/w). An aluminum mold (Al5083 alloy) was designed and built for resin transfer molding to obtain and optimize the processing of these composite and nanocomposite samples. Subsequently, physicochemical characterizations were carried out and the mechanical, tribochemical and thermal properties of specimens (CPs) of the GFRP rebars were evaluated. Through the microanalyses obtained in scanning electron microscopy (SEM) and chemical analysis by energy dispersive X-ray spectroscopy (EDS) it was possible to obtain the percentage of carbon, the dispersion and distribution of glass fibers and graphene nanoplates, as well as evaluating the morphology of the composites. Thermal (DSC, TGA, thermal diffusivity test using the flash laser method), mechanical (3-point bending and impact) and saline degradation tests were carried out on the GFRP rebar samples to evaluate the type of tribochemical wear of the nanocomposites with the objective of comparisons of these properties between them and also in relation to metallic rebars (CA50). The evaluation of the nanocomposites with SEM/EDS showed a slight increase in carbon as the graphene concentration increases in the samples, confirming the presence of graphene added during the processing of the CPs. The values obtained for the flexural strength at 3 points showed that there was a significant variation of this property for the different composites, for the sample G05 (0.5% graphene), the flexural strength value had a gain of 41.1% in compared to the Rover sample (0% graphene), reaching (80.8±1.0) MPa. In addition, the values obtained in the impact tests showed that the addition of graphene in the composite also promoted a significant increase in impact resistance compared to the traditional composite Rover sample, with the G07 sample showing an increase in impact resistance of 43.5% in compared to the Rover sample. The compiled results indicate that graphene nanocomposites for GFRP rebars have numerous competitive advantages over steel rebars, and may be a future option for trade-off in constructions in marine environments.

The nitriding process performed through machining by electrical discharges is a method that combines themachining of complex geometries parts to the ability to obtain thermochemical nitriding treatment on their surface. This study aims to evaluate the results of nitriding by electrical discharges on AISI 4140 steel, using as a dielectric fluid, a mix of deionized water with diluted pharmacological urea and the addition of silicon carbide powder to the fluid, in different proportions. Nitrogen, as the element to add surface hardness in steel, comes from the urea that is part of the dielectric fluid used in the process. A properly adapted penetration EDM machine was used to carry out the experiment. Twenty-five identical samples were prepared and machined by electrical discharges using a graphite electrode. The characterization of the sample was made via Vickers microhardness test, evaluationof surface roughness and optical microscopyand x-ray diffraction techniques. Additionally, the machining performance was evaluated in all sets of samples, with and without abrasive powder concentration variation. The results obtained show the formation of the nitrided layer in the steel with an increase of up to 110% in surface hardness in relation to the substrate, change in machining performance and reduction in surface roughness when abrasive powder is added to the dielectric fluid.

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Fuel cells are being considered as the most promising source of energy of the future, it meets the necessary requirements for the preservation of the environment, and the demands of energy, had today as more clean, safe and highly efficient sources in the modern world. The advances in research carried out in the last 40 years have made fuel cells competitive and / or viable for several applications. In Brazil, due to the great hydroenergetic potential and flex technology with the use of ethanol in automobiles, the use of fuel cells as a stationary power generation system or in motor vehicles, may be extremely feasible due to the possibility of concomitant use with catalytic reform of ethanol for H₂ production. In this work it was studied the manufacture of active components of these cells (Pt/C catalysts and without platinoids) from graphene oxide composite used as a support and impregnated with platinum and another possible catalyst by the process of photoposition to UV radiation. As a preliminary step, the influence of exposure to UV radiation from two graphene oxides used as a catalyst support at 3 different pH solutions was also studied. Firstly, results from the MEV-EDS, DRX, FTIR, TGA and Raman characterization techniques proved the photoreduction capacity of oxygenated functional groups of GOs submitted to UV radiation, with acid pH being the most effective and consequently the one chosen for the photodeposition process. Subsequently, the process of exposure to UV radiation was used to obtain the catalyst, the formulations being composed of the 2 GOs previously tested in combination with the platinum precursor H₂PtCl₆. Finally, a catalyst formulation containing the two graphene oxides, one acting as a support and the other as a catalyst was obtained by the same process. The results of the MEV-EDS, DRX and FRX characterizations confirmed the success of the photodeposition process and cyclic voltammetry tests confirmed the electrochemical potential of the materials obtained.

Cellulose acetate (CA) nanofiber blankets have great potential for application as a scaffold, in Skeletal Muscle Tissue Engineering, for combining properties such as high surface area, high porosity, and interconnection between pores, in addition to presenting good biodegradability characteristics mechanical properties, and hydrophilicity. However, some limitations need to be overcome, among them, the low cellular infiltration inside electrified nanofiber blankets and the chemical composition that favors the biomaterial/cells interaction for the generation of living tissue. Thus, this project proposed the modification of the surface of polymeric nanofibers of CA with alginate particles, through the combination of electrospinning and electrospray techniques, with the objective of creating a surface with chemical characteristics more like the extracellular matrix (ECM). The process parameters and the characteristics of the solutions for obtaining CA nanofibers and alginate particles were studied separately. Subsequently, adaptations were made to the electrospinning equipment to produce nanofibers and nanoparticles in a single process, producing a hybrid material. The morphological characterization of the nanostructures obtained was carried out by SEM, the chemical characterization by FTIR, the thermal property was evaluated by TGA, the hydrophilicity was evaluated from the swelling test in liquid medium. The CANF produced by the electrospinning technique presented a morphological structure in the cylindrical shape and elongated with diameters in the order of magnitude around 181 nm. The crosslinked alginate particles had dimensions varying between 146 and 1418 nm. The CANF blankets covered with crosslinked alginate particles have diameters in the order of magnitude around 218 nm, with an average diameter varying from 143 to 291 nm. It appears that the blankets of CANF/R-ALG showed greater swelling compared to pure CANF, presenting a percentage of water absorption in the range of 250 to 450%. This is a positive effect on the cultivation of some cell groups in vitro that require a material with charge for better cell adhesion, growth, and differentiation.

Self-healing are a new class of intelligent materials with the ability to partially or fully recover functionality after a defect has arisen. It is known that the mechanical properties of ceramic materials limit their use in some applications, as they are subject to fragile fractures. Self-healing applied to these types of materials can increase their useful life and be economically viable, since it will not be necessary to replace them whenever a defect arises. In addition, self-healing can be carried out in situ, thus reducing part repair time. Within this context, this work evaluated the self-healing capacity of a ceramic material produced, by uniaxial cold pressing, with alumina (Al₂O₃), silicon carbide (SiC) and magnesium oxide (MgO). The raw materials were characterized by X-ray diffraction, X-ray fluorescence and laser diffraction particle size. The specimens were produced by varying the SiC/Al₂O₃ ratio (0.2, 0.3 and 0.5) and keeping the percentages of MgO (3% by mass) and binder (6% by mass) fixed. To assess self-healing, a discontinuity was generated on the surface of the specimens (after drying and sintering at 1400ºC) using a durometer with a conical diamond indenter and applying a load of 20 kfg. The healing time in the oven, at a temperature of 1000ºC, was 1 minute, 30 minutes and 1 hour. To evaluate the self-healing efficiency, the specimens (sintered, indented and after curing) were analyzed in terms of water absorption, porosity, bulk density and flexural strength. The results showed a reduction in shrinkage with increasing silicon carbide content and decreasing alumina content. The increase in SiC content did not influence the bulk density value and the healed samples had lower water absorption values. For lower SiC contents there was an increase in porosity varying the healing time, which may be related to the possible occurrence of thermal shock in the parts and the formation of cracks. By increasing the SiC content, it is possible to see that with healing there was a decrease in apparent porosity, evidenced for the samples containing 20% of SiC. From the results obtained it is possible to infer that, for the mixture containing 15% of SiC, the specimens healed at 60 minutes had an increase in flexural strength of 84.9% when compared to specimens that were only indented and, for specimens containing 20% SiC, this increase was 61.1 % for the time of 30 minutes and, for the specimens containing 30% of SiC, this increase was 41.9% for the time of 1 minute. For the 30-minute healing time there was a reduction in the size of the discontinuity in the specimens by about 19.1%, 14.8% and 18.93% for the formulation containing 15%, 20% and 30% of SiC , respectively. The results obtained are indicators that the materials produced are capable of self-healing.

In this work, the effects of reduced graphene oxide (rGO) on the tribological behavior of the ultra-high molecular weight polyethylene (UHMWPE) under sliding contact conditions were studied through the correlation of morphology, mechanical and surface properties with its tribological behavior. The UHMWPE/rGO nanocomposites were prepared at 0.010, 0.10, 0.25 and 0.50 wt.% rGO contents. The sliding wear tests were performed at a pin-on-disc configuration, with a polymeric disc sliding against a tungsten carbide-cobalt alloy pin counterface. The worn surfaces were evaluated by profilometry and optical microscopy, in order to identify changes in the wear mechanisms resulted from the presence of rGO at different contents into the UHMWPE matrix. The nanocomposites morphology was evaluated by scanning electron microscopy images and the degree of crystallinity was obtained by differential scanning calorimetry. The mechanical properties were evaluated by Shore D hardness, Vickers microhardness, and instrumented indentation measurements. The surface properties of both pin and nanocomposites faces were evaluated by contact angle measurements, and the surface energies and the adhesion work of the pin/nanocomposite pairs were estimated. The nanocomposites structures with 0.10 and 0.25 wt.% of rGO exhibited a higher degree of crystallinity when compared to the neat polymer and the high dispersion level of the nanofillers at the matrix. Shore D hardness and Vickers microhardness values increased up to 7% and 25% compared to the neat polymer, respectively, as function of the rGO content. On the other hand, the greatest values of instrumented hardness and elastic modulus were obtained by the nanocomposites with 0.10 and 0.25 wt.% of rGO, with around 40% of increase, and the lowest work of adhesion with the pin surface. Additionally, the coefficient of friction (μ) of these nanocomposites was around 50% lower when compared to neat UHMWPE. Three different scenarios of the wear mechanisms took place at the sliding contacts, where each one depended on the testing materials' properties.

Literature has recently shown that aluminum (Al) matrix nanocomposites with graphene (G) reinforcement have attracted attention mainly due to their high physical properties/density ratio. Al and its alloys, in turn, are commonly used industrially in the electrical, automotive and aerospace sectors in various applications that require materials with high mechanical resistance, good conductivity, low density and a significant cost-effective comparative advantage. Graphene, an allotropic carbon, has a very low density, low coefficient of thermal expansion, in addition to reasonable mechanical and electrical properties. In this work, it was sought to improve the melt processing in an inert atmosphere to evaluate the properties of nanocomposites with an SAE 323 aluminum alloy matrix with graphene reinforcement. The graphene material used had up to 30 layers, being added in proportions of 0.5%, 1% and 2% m/m. To obtain the specimens (CPs) by melting in a resistive furnace, adaptations to avoid oxidation were carried out using a nitrogen (N₂) gas atmosphere. The tests of physical-chemical and microstructural characterizations of the PCs were performed by scanning electron microscopy coupled with energy dispersive spectroscopy (SEM/EDS) used to determine the percentage of carbon, to determine the incorporation and dispersion of fractions of graphene and evaluate the morphologies. The mechanical, electrical and thermal tests performed were: hardness (HB and HV) to evaluate the mechanical properties; electrical conductivity test to evaluate the electrical properties (conductance) and thermal conductivity test, using the quadruple thermal method (laser flash) to evaluate the thermal properties (thermal conduction). It was found that in the nanocomposite that the reinforcement material was dispersed and found both in the matrix and in clusters, and the mechanical properties did not show changes, whereas the electrical and thermal properties were slightly modified.

Thermal and optical behavior of some materials are important issues
concerning energy consumption and economic aspects. This work tests five different
paints applied on steel plates. Temperatures values were measured considering
three different distances of an infrared (IR) radiation source (lamp) and three types of
air flow acting on coated plates. Diffuse reflectance of the paintings was also
measured by a spectrophotometer for wavelengths from 250nm to 2500nm. Infrared
thermography and simulations using finite element software were also done as
complementary characterizations. Results shows profile temperature curves for
external and internal surfaces of the plates, and for the interior of a prototype. Based
on these tests, thermal behavior analysis concerning the tested configurations,
thermal conductivity coefficient estimation and economic aspects assumptions were
made. It was also possible to predict the economic benefits/penalties on buying high
reflectance inks instead off common ones. Some other analysis such as: surface
appearance, assumptions about heating and cooling behavior, heat flux distribution
and surface discontinuities, were also made for each material. Results shows that,
proportionally, interior temperature was higher for cool paints, when compared with
common white one at 60 cm distance from radiation source. On the other hand,
however, cool paints have a tendency of keeping interior “cooler” when external
temperatures are higher. Based on the measurements made, the use of cool paints,
reduced, on best cases, the interior temperature of the prototype by 9.1% (-2.83 °C)
at 40cm from the radiation source and by 22.2% (-7.13 °C) for 20cm distance from
the radiation source (when comparing them with the regular acrylic based white
paint). Comparing with solar irradiation that reaches The Earth surface, the radiation
source of 250W power, on a 0.09 m 2 surface area, represents a value about 1300%
higher. The study also showed that pigment color has a major influence on the
results and so, black paintings had the worse efficiency, as was expect.

The purpose of this work is to evaluate the potential of the use of mining tailing from K-feldspar mining as raw material for the synthesis of geopolymeric materials that will be used in the construction of pavers for pavement. Contemporary organizations are showing increasing interest in the reuse of solid waste from industrial processes with the intention of reducing environmental impacts and reducing costs. Mining activity is one of the main waste generators in Brazil. In parallel, geopolymeric materials have been gaining prominence in studies that place it as a possible substitute for ordinary Portland cement, due to its advantages from the environmental point of view. In this work, different types of mineral waste from K-feldspar extraction (gray, yellow, mixed) will be subjected to characterization tests (x-ray fluorescence, particle size analysis and X-ray diffraction) in order to ascertain the potential of these materials as precursors for the production of geopolymeric cements. Different formulations will be carried out by varying the contents of the residue and the activators. The geopolymeric materials resulting from each formulation will be subjected to tests of compressive strength, MEV, X-ray diffraction and BET in order to verify the success of the geopolymerization reaction. The formulation resulting in a geopolymer with a higher compressive strength will be used for the fabrication of pavers and, these, subjected to compression strength test and abrasivity test. In this way, it will be possible to investigate the feasibility of using this waste and the use of geopolymerization in the production of paving materials.

Construction niches are materials that have a biotic load in their composition and present the potential to create an environment colonizable by several organisms of a affected region after mining activity. The use of soil in its composition causes the material to possess this biotic load and the use of iron ore tailings as a constituent is an alternative for a sustainable use of the minetailing in order to promote its return to the environment in a sustainable way. The vegetation type most impacted by mining is the Campo Rupestre, and for this reason, the construction niches present potential to promote the rehabilitation of species in this environment after mining activity. This research aims to evaluate the capacity of a construction niche to promote the growth of species in the laboratory and to be colonized in a natural environment. The niches will be prepared from the combination of different proportions of iron ore tailing, soil and binder materials. The establishment of organisms on the surface of the constructed niches will be analysed by performing bioassays under controlled laboratory conditions and under natural conditions in the Campo Rupestre in an area located in Vázea do Lopes region. The niches will be characterized for their mechanical strength (flexural test), microstructural (porosity, specific surface area and MEV), chemical and mineralogical composition (XRD and FRX). The growth of organisms in the construction niche may be an indicator that this restoration method can promote the rehabilitation of species and create new ecological niches by accelerating the recovery of ecosystems in rocky outcrops.

Thermoplastic Polymeric Materials have high potential for large scale production at low cost. The use in solar collectors is currently restricted the applications of low temperatures, generally for the heating of swimming pools. The greatest limitation in relation to the metallic collectors is the due to the low thermal efficiency in temperatures higher than 40°C. The present work consists on the development of a polymer matrix composite with the application of dispersed carbon-based additives to increase the thermal conductivity (usually between 0.1 and 0.4W/m.K) and to values higher than 1W/m.K , thereby improving the thermal performance of polymeric solar collectors. Cylindrical test bodies will be produced in Acrylonitrile Butadiene Styrene (ABS) for the measurement of thermal conductivity. Initially the pellets of the polymers (virgin and recycled) will be extruded for the dispersion of the additives and then thermoformed in cylindrical bodies for the measurement of the thermal conductivity. The measured data will be used in numerical simulation software to predict the performance of solar collectors manufactured with the obtained materials.

Due to its commercial importance, an aluminum-silicon alloy was subjected to machining by electric discharges in aqueous medium containing urea, in an attempt to obtain a machined surface enriched with nitrogen and harder than the base metal. The samples were machined in deionized water and urea (33.33g / L) solution with different electrodes (electrolytic copper and graphite) and had their Vickers microhardness values measured. In addition, X-ray diffraction assay was performed to identify the crystalline phases present on the surface before and after the machining process. The morphology and thickness of the machined surfaces were analyzed by scanning electron microscopy. With the tests carried out, it was possible to verify that, after machining by electric discharges, there was an increase in surface hardness of over 55% and the appearance of new crystalline phases in the machined surface, possibly of oxides and aluminum nitride. The morphology of the machined surface presented fragile elements similar to those reported in the literature (spherical pores and voids of irregular geometry), and an optimization of the machining parameters was necessary to correct this problem. Since nitride peaks coincide with peaks of aluminum oxides in the diffractograms, a complementary chemical characterization is required to confirm the occurrence of nitriding.

CA6NM cast martensitic stainless steel is used in the construction of rotors, components used in hydraulic turbines. Your choice is due to manufacturing cost and operating performance. A similar weld metal is used in the repair or manufacture of these rotors, containing 13% chromium, 4% nickel and 0.4% molybdenum, with carbon contents below 0.04%. Through the use of double-stage tempering heat treatment, it is possible to obtain higher values of toughness. The aim of this study was to evaluate the effect of temperature on the microstructure and toughness of this weld metal, analyzed under five different conditions, in addition to as welded. The microstructures were analyzed using Optical Microscopy (MO) and Scanning Electron Microscopy (SEM). The amount of austenite retained was obtained by performing X-Ray Diffraction (XRD). The mechanical characterization of the weld metal was carried out, with the performance of the V-notch Charpy test, to obtain the toughness, and the Vickers hardness test. In all conditions analyzed, retained austenite was formed, however, the highest levels were found in double-stage heat treatments. The tempering carried out at 580 ° C / 2h was what led to the obtaining of the lowest fraction of retained austenite, while at 650 ° C / 2h + 580 ° C / 4h the highest content of this constituent was obtained. The toughness value of the weld metal was directly proportional to the percentage of retained austenite found. As for hardness, this relationship was reversed. In all the analyzed conditions, the material presented more characteristic of fragile fracture. The best mechanical properties, according to the objective of the present study, were found in the double stage heat treatment.

Microallyed steels with niobium and vanadium have been outstanding in recent years, this is due to the great potential of use in structural applications, especially in long products of high strength. Addition of alloying elements, together with the TermoMechanical Control Process, provides formation of homogeneous microstructures, besides increasing the strength concomitantly with the increase of. This occurs due to the grain refinement and the formation of precipitates, which is a phenomenon peculiar to high strength microalloyed steels (HSLA). However, the use of micro-alloying elements has not yet been extensively studied, especially for steels with high equivalent carbon content. A high value of equivalent carbon added by elements such as V and Nb can lead to deleterious effects on the material if no precautions are taken during the welding process. Studies indicate that the main problems found in the welding of microallyed steels are related to heat input, which may affect the HAZ characteristics of these metals. Thus, depending on the chosen heat input, the value of equivalent carbon and on the type of element, it will be possible to have changes in the width, hardness and microstructure of the HAZ. This may affect the characteristics of these steels when applied as reinforcing bars. Thus, the objective of this work was to evaluate the effects of heat input and niobium addition on the HAZ of high carbon equivalent vanadium microalloyed steels for application as reinforcing bars. Thus, welds were carried out on V and NbV microalloyed steel rebars by the GTAW (Gasshielded Tungsten Arc Welding) process. The results indicate the coarse grains region of HAZ as the most critical place during welding. Abnormal grains (> 100µm) for welding with high heat input or the presence of martensite in low heat input were observed. Both phenomena are also related to Pcm (critical metal parameter) and the niobium content, which may favor or delay these occurrences. On the other hand, the results do not indicate softness in any region of the HAZ, proving to be an advantage, either in terms of applied heat input or by the addition of niobium in the steels.

The increase in demand for polymeric material, especially in structural applications, calls for the need to produce bigger and more complexes parts that must meet strict standards. Although polymers easy processability, properties as low melting temperature, low thermal conductivity, low diffusion capability and low wettability, together with a wide variety of grades and mixtures, hinders the achievement of an efficient union and high productivity. Among the many polymeric-union processes, one of the most recent is the Friction Stir Welding, that relies on the heat and mixture of materials by the friction between a rotation tool and the substrate. Therefore, the present work aims to investigate the influence of the tool geometry, rotational speed and welding velocity on polycarbonate plates. It was observed that higher rotation speed results in an increase of temperature leading to more homogeneous mixture and a welding bean free of visual defects. The increase of welding speed reduces the peak temperatures achieved in the plate for both tools. The relation R/T was measured as 78.2 for cylindrical plunge and 65.5 for conical plunge, this last reached better mechanical properties due to their greater surface with the substrate and smaller volume of affected material. The best ultimate tensile strength measured, 33.96MPa, is 54% of the one measured for the unprocessed material plate, and that value was measured in the weld made using the conical plunge at a rotation speed of 2160rpm and a welding speed of 40mm/min. The results exhibit the applicability of friction stir welding in polycarbonate, and the relation R/T enables an efficient prediction of welding parameters to optimize mechanical properties for each tool.

Every day the market becomes more competitive, which makes Engineers and Material Scientists develop mechanisms for more economical solutions and processes. Electrical discharge machining (EDM) is a process that is being researched for allowing some adaptations to be made obtaining the feasibility of machining metallic materials, immersed in aqueous solution containing urea, generating a surface enriched with nitrides, which increases the hardness of the part and consequently increase the useful life. In this work the feasibility of nitriding samples of austempered nodular cast iron (ADI) and verify the formation of the nitrided layer on the surface of the material was studied. The tests for the evaluation of the process were: Hardness tests of the ZR layer and ZAC, evaluating the mechanical properties; by means of X-ray diffraction (XRD), determine the nitrides formed in the nitrided layer; to measure the thickness of the nitrided layer, the formation of the recast zone and the heat affected zone (ZAC) using optical microscopy and scanning electron microscopy (SEM) and to evaluate the performance of the copper and graphite materials by quantifying the wear of Copper and graphite tool electrodes as a function of the material removed, calculating material removal rate (TRM), copper electrode wear rate and graphite tool (TD) and relative volumetric wear (DVR). The results showed nitrided layer formation on the surface of the samples machined with the two types of electrodes. A significant increase in hardness values was observed. 

Changes in the mechanical efforts combination applied on metallic material during a forming process also changes the strain path. It influences on the mechanical behavior of many alloys, which depends on the mechanical processing applied and the structural particularities of the alloy. Although the AISI 430 stainless steel is ferritic, austenite can be obtained in its microstructure at high temperatures. Which makes possible increase the steel hardening by quenching, due to the formation of martensite. It was studied the mechanical behavior of the AISI 430 ferritic stainless steel after different combinations of strain path and heat treatments. AISI 430 ferritic stainless steel sheets were characterized using tensile, shear, Vickers hardness, metallographic and X-ray diffraction tests. The steel was characterized as received and after annealing and quenching. Samples were annealed, pre-deformed (tensile, shear, straight-reverse shear, cold rolling and combination of traction with shear and cold rolling with shear), heat treated in quenching and, after, tensile tested and/or shear tested again. The quenching heat treatment promoted the formation of martensite in the AISI 430 steel, increasing its mechanical strength and decreasing its ductility, even when the steel was pre-deformed before the quenching. In addition, the Bauschinger effect occurred when straight-reverse shear efforts were applied with the quenching heat treatment between the loadings. In general, the lower the amount of pre-deformation imposed, the higher the mechanical strength of the AISI 430 steel after the tempering heat treatment. Which indicates that the lower density of discordances favors the martensitic transformation.

Understanding the phenomen at hat occur during the machining processes contributes to the in crease of the predictability, which allows a great erefficiency during the manufacture. The comprehend the influence of variables and machining parametersis of fundamental import anceto understand the process behavior. Milling is characterized by high rate of material removal and interrupted cutting. This intermittence causes the cutting tool to be subjected to cyclic alvariations of temperature and tension, which dis advantage the application of cutting fluid by the tradition al method in the process. In this work the influence of the machining direction was evaluated on the wear evolution of the cutting tool in the face milling of the SAE 1045 steel in dry condition and with the application of cutting fluid through the technique of minimum quantity of lubricant. The machining directions adopted were longitudinal, along the leng thof the work piece, and transversal, along the width of the work piece. Square section bars of SAE 1045 laminated steel with dimensions of 100mm x 400mm were used, also carbide cutting tools. The tests were conducted by dry and with MQL application with two diferente cutting fluids. In each test condition the worf pieces were machined in the longitudinal and transversal directions, resulting in a total of sixtest conditions. Simultane ously with the millhing tests, the mechanical vibration signal sof the system were collected. The wear evolution in the cutting tools was analyzed with the optical microscope. At each stop for analysis the tools, therough ness of the surfasse was evaluated in the work pieces. At the end of the tests in each condition, the tools were analyzed by scanning eléctron microscopy, which allowed the identificati ion of the forms and the mechanisms of wear. In general it was observed that the application of the MQL was beneficial to the life tools and, in some cases, improved the surface finish of the part. The signs of mechanical vibrations collected were related with the evolution of tool wear.

The present work evaluated mechanical behavior of high performance fiber performance cementitious composites (HPFRCC), before and after thermal treatment. For this, reinforced specimens with 1%, 3% and 5% fibers by volume were molded, using the methodology of infiltrated slurry, after dispersion of the reinforcement in the molds. The concentration of fibers occurred in region subjected to traction during bending stresses. After curing at 7, 14 and 28 days, all specimens was bending tested, with half being heat treated at 250 ° C and with gradual heating in an electric oven. It has been observed that exposure to temperatures around 250 °C improves mechanical performance of HPFRCC with the proposed fiber distribution. The composite reinforced with 5% of fibers, submitted to thermal treatment, showed bending resistance between seven and eight times greater when compared to the control group without reinforcement and without heating. The results of statistical analysis revealed that increase in age, increase in fiber content and the application of heat treatment contributed to increase in strength, toughness and deflection. The pull-out assay revealed that fiber-matrix bond is cohesive and confirmed influence of heat treatment on fibermatrix bonding mechanism. The images obtained by digital and scanning electron microscopy helped to understand the fiber-matrix interface, showing bonding surface between composite elements, and confirmed that heat treatment promotes a change in the surface of steel fibers. The cracking profiles did not exhibit a defined pattern and presented distinct designs with distortions and inclination tendencies as the fiber content increases.

Duplex stainless steels (AIDs) are metal alloys that have a microstructure consisting of approximately equal volumetric fractions of ferrite (a) and austenite (g).Due to this fact, this type of material has an excellent combination of mechanical properties and corrosion resistance. Because of this, DSSs are widely used in a variety of fields.However, when the DSSs are exposed to high temperatures (650 to 950ºC) their microstructure can undergo modifications and exhibit deleterious phases, which deteriorate its properties. Among the phases, the most deleterious are the sigma (s) and chi (c) phases.Such phases, even in small fractions, can cause significant drops in the mechanical properties and corrosion resistance of the DSSs.Given this, the aim of the present work was to characterize the material from the conditions of heat treatments (HTs) in which it was submitted, to analyze the influence of the intermetallic phases, especially the σ phase, in the mechanical properties of the UNS S31803 DSS and determine the kinetics of the σ phase formation.To this end, a computational thermodynamic simulation was initially performed to calculate the fraction of the phases present in the equilibrium.Subsequently, isothermal aging HTs were performed at 750, 800 and 850ºC at different times to induce s phase precipitation.Subsequently, the samples were subjected to the metallographic preparation. After that, the material was microstructurally characterized by optical microscopy (OM), scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques.Subsequently, the quantification of the phases present in the material was carried out using the techniques of quantitative stereology and a feritscope. Finally, a model was proposed to predict the the kinetics of the σ phase formation (activation energy) from the Avrami equation.In addition, tests were also carried out for the mechanical characterization of the material through the hardness, ultra-microhardness, tensile and impact (Charpy-V) tests.Results of the microstructural characterization showed that the s phase precipitated gradually in the material microstructure as a function of the time of exposure of the material to the HTs, but there are significant deviations between the phase quantification techniques.Moreover, results of the mechanical characterization showed that the increase in the fraction of s in the material microstructure increases the hardness, the yield strength, the ultimate strength and decreases the elongation, in addition to the impact toughness, deteriorating the mechanical properties of the material.

The increasing technological development increasingly demands materials and components of high mechanical performances, thermal, chemical resistance associated with low specific mass. These demands can be found in carbon fiber reinforced epoxy polymer matrix composites. In addition, the doping of this type of composites with carbon nanotubes (CNT) further enhances their properties. This work evaluated the formation of a new phase in composites in the interface region between the epoxy matrix and oxidized carbon fibers with sizing of functionalized carbon nanotubes, besides evaluating variations in mechanical resistance. Was fulfilled the sizing of carbon nanotubes at the levels of 0.10%, 0.30% and 0.50% by weight by the coating method. The micrographs obtained by scanning electron microscopy (SEM) indicated good dispersion in the deposition of 0.10% and 0.30% of CNT, while the 0.50% content presented the formation of agglomerates. The evaluation of the interface in the composites using atomic force microscopy (AFM) indicated the formation of a new phase after the superficial treatment of the fibers, whereas the scanning electron microscopy showed a better adhesion of the epoxy resin in the carbon fibers after fracture to the contents of 0.10% and 0.30% of carbon nanotubes. The tensile test showed a 24.2% increase in tensile strength, 18.0% in the modulus of elasticity and 22.2% in the toughness for 0.10% CNT deposition, while the flexural test showed a increase of 30.16% in the rupture limit stress and increase of 77.2% in the modulus of elasticity to 0.10% deposited CNT. The deposition of 0.50% did not show significant variations. The values for impact strength were statistically the same for all samples. The results indicated the formation of the interface of higher mechanical strength in the composites made after sizing of CNT by 0.10% and 0.30%, which reflects in its better mechanical properties.

Hot work tool steels are those used in tooling that work at high temperatures reaching up to 500 ° C in operation. Are mainly applied in the manufacture of forging, extrusion and die castings. They need to present characteristics such as, high tenacity, tempering resistance, mechanical resistance at high temperatures, high thermal conductivity and others. Thus, the heat treatment is the step that defines the final mechanical properties of these materials, being considered the most critical step in the process of tooling construction, although it only comprises 5% of its total cost. In this context, the objective of this work was to evaluate the microstructural influence and mechanical behavior of three different hot work tool steels, AISI H11, AISI H13 and DIN 1.2367, when subjected to different parameters of heat treatment of quenching and temperingsubsequent. The evaluation was performed using techniques ofoptical microscopy and scanning, as well as mechanical tests of hardness, microhardness, impact and tensile test. The results showed that the increase of the austenitization temperature in the tempering promoted an increase in the hardness of the materials, due to the increase in the volumetric fraction of the martensite formed, in detriment of the essentially ferritic microstructure with dispersed carbides observed in the annealed alloys. It was also observed that the microstructural evolution as a function of the increase of the austenitization temperature. It was verified the phenomenon of secondary hardening experienced by these materials in the tempering stage, as well as the influence of austenitization and tempering temperature on the mechanical behavior of the materials.

The application of titanium alloys in the market has good acceptance and notoriety in several segments, such as aerospace, naval, biomedical and aeronautics. The diversity in its applications is basically due to the association of several interesting mechanical and physical properties in the industrial application, such as good strain strength, corrosion strength, critical cryogenic capacity and low density. However, titanium alloys does’t present good wear strength often preventing it from being used as a parts subject to slipping. In order to improve the wear strength, studies have shown the ability to nitrate the surface layer of the titanium sample through NDE (Nitriding by Electrical Discharge), joining process with the heat treatment, making it possible to combine techniques once performed separately. Researches also showed that by combining powder mixed with the dielectric fluid,such as silicon carbide significant changes were achieved as in the improved rate of removal of the material, the reduction of surface roughness, the wear rate of the electrode.The purpose of the present work is to nitrate by ion implantation a Ti6Al4V titanium alloy in an EDM machine using deionized water and urea (which is the source of the nitrogen element) with the addition of the carbide abrasive powder of silicon in predetermined concentration. The electrodes used were electrolytic copper and graphite. Characterization techniques such as optical microscopy (OM), X-ray diffraction (XRD), scanning electron microscopy (SEM), microhardness and surface roughness measurements were applied.

This study aims to produce alkali activated materials (AAMs) with self-cleaning properties from industrial wastes. Many results in literature show promising results with AAMs, often surpassing the performance of ordinary Portland cement (OPC) in many tests. Two precursors will be utilized to manufacture this AAM, both are industrial wastes, the first derives from the material placed in waste piles by a phosphate mine, while the other is eucalyptus fly ash (EFA). These materials will be characterized through spectroscopy via X-Ray fluorescence (XRF), X-Ray diffraction (XRD) and Fourier-transform near-infrared (FTIR); also scanning electronic microscopy (SEM), density tests, loss on ignition (LOI), thermogravimetry analysis (TGA) and particle size analysis. The research done on the topic supports the possibility of alkali-activating these types of materials and gives a range of values for variation, within which the activation can be performed. In this sense, the experiments will be design (DoE) using statistical modelling of mixtures to obtain the composition that shows the best results, also to understand how each variable and/or interaction affects the performance of the material. Once produced the AAMs, they will be tested for mechanical strength and durability through standard test for OPC, also they will be analyzed via SEM to evaluate the phases formed after activation. The self-cleaning potential will be determined by immerging samples of the materials into methylene-blue aqueous solutions, the solution will then be sampled and analyzed to determine its concentration after regular time I intervals, which will be done in a UV-Vis spectrophotometer.

High Chromium White Cast Iron (HCWCI) is a special type of cast iron that receives additions of alloying elements. HCWCI receives additions of up to 30% chromium, according to American Society for Testing Materials (ASTM) A 532, giving this material a high resistance to wear and corrosion. HCWCI is used in severe wear regime environments, showing itself as one of the most cost-effective materials for this type of regime. Mining is an example of the application of this material to parts such as wear plates and ore pulp pumps. Research carried out adding niobium to this alloy obtained positive results, increasing the resistance to wear with insertions of mass percentages between 0.5% and 1% of niobium by weight. The HCWCI is considered a hard machinable material due to the high content of carbides, which associated with the matrix, form a rigid microstructure and high hardness. The material used in the research was developed by the casting process and later characterized, since it is not a commercial material and that the knowledge of its microstructure and its properties are important to evaluate the characteristics of this material in relation to its machinability. The machinability was analyzed in the material with and without addition of niobium, varying the cutting parameters: cutting speed; feed and dry cut and lubricated-cooled condition. The output parameters analyzed were: tool life; roughness and wear mechanisms. The addition of niobium caused reduction of the volumetric fraction of carbides, reduction of hardness, refinement of the microstructure and contributed positively to the machinability of the HCWCI. The increased cutting speed strongly impacts on cutting tool cutting life, increasing the feed rate can be interesting in the volume increase removed, having a low impact on the life of the tool. The use of cutting fluid can bring significant contributions to the process, especially in relation to the roughness and the useful life of the tools. The cutting fluid influences the wear mechanisms of the tools.

The research about self-cleaning surfaces has been gaining space in both academic and commercial areas due to the various possible applications for this type of surface, such textiles, windows, mirrors, photovoltaic modules, etc. One of the materials most used as thin film self-cleaning is titanium dioxide (TiO₂), because it is a compound abundant in nature, non-toxic, it causes reduced environmental impact, it has high photochemical activity, low cost, chemical stability in systems aqueous solution in a wide pH range and low band gap value (3.2eV for the anatase). The self-cleaning property of thin films of titanium dioxide is related: photo-induced hydrophilicity and photocatalytic activity.

In this work, the self-cleaning ability of some thin films will be evaluated by comparing uncoated glass substrates with substrates coated with TiO₂ pure films, and TiO₂/SiO₂ composites. The films were obtained through sol-gel process through a dip coating. In addition to the film characterization obtained by the measures of transmittance and contact angle, special attention will be given to the accumulated soiling (soiling effect) on glass substrates, coated and uncoated, due to their exposure in the environment for a period of 11 months. The disclosure occurred in an urban area of the city of Belo Horizonte, Minas GeraisThe main objective of the work is to relate the composition of the thin films to the amount and composition of the deposited dirt, therefore, evaluating the self-cleaning properties of the films and verifying if they are able to inhibit or reduce the accumulation of cracks or the development of biofilms.

Portland cement is the most widely used material in the world, so improvements in cost, quality and efficiency are important. Based on this purpose, several materials are studied with the objective of partially replacing the clinker used in cement production. In particular, two industrial wastes may promote such substitution, being the depleted mixture from the manufacture of metallic magnesium as a source of calcium oxides and silicates, and red mud, a residue from the refining of bauxite, by virtue of its composition indicate pozzolanic properties. The present study made the chemical and physical characterization of the studied materials, by means of X-ray fluorescence (FRX), granulometric analysis, X-ray diffraction (XRD), scanning electron microscopy (SEM) Luxan, Chapelle and thermogravimetric analysis. The total percentage of Portland cement replacement by the two wastes was 25%, with variations of the individual amount of spent mixture and red mud. Cylindrical and prismatic test specimens were used to evaluate mechanical strength and porosity at the ages of 7, 28 and 91 days, through the water absorption test and mechanical compression and bending tests. The fine granulometry (less than 45 μm) and lower water absorption by the composite with substitution indicate a possible filer effect of the study material. The Luxan and Chapelle tests showed that there is pozzolanic activity in the material. The responses obtained by the mechanical tests were favorable because the replacement did not compromise the performance of the material, presenting results at compressive strength higher than that established in standard (40 MPa). The tensile strength in flexion was compatible with reference. The use of tailings as a substitute for Portland cement proved to be effective in promoting lower energy costs, reducing CO₂ emissions and giving sustainable disposal to industrial waste.

Currently, the high demand for organ and tissue transplants and grafts has driven the evolution of tissue engineering, the area of science that aims to promote the development of specific tissues through the cultivation of stem cells. The development of stem cells is based on their seeding in an artificial structure composed of a biomaterial that mimics extracellular matrix functions in human organs and systems. In search of a solution for tissue vascularization, several decellularization studies have been promoted. It is a technique of removing cells from the organ with maintenance of the extracellular and vascular matrix, which will be used as a natural matrix for cell recellularization. Considering the features of cellulose as a biomaterial, the scarcity of organs for the decellularization process and the similarity of the mammalian vascular network with some plant species, this study aims to evaluate the properties and features of a leaf after the decellularization process and its potential for use as a scaffold. Immersion and perfusion techniques were used as decellularization protocols and the final material was subjected to scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and differential scanning calorimeter (DSC). The plant decellularization was considered a viable and low cost option, wich results in acceptable structural changes but still requires additional tests for biological applications.

High chromium cast irons (HCCI) are important alloys currently used in a variety of applications that requires high abrasion resistance such as mineral processing, slurry pumping and pulp manufacturing industries. The outstanding performance of these alloys is due to the presence of hard carbides in a matrix composed mainly by martensite and austenite. Their microstructure can be altered by addition of alloy content and heat treatment, in order to enhance mechanical properties. In this study, the influence of destabilization heat treatment - 950°C, 1000°C and 1050°C - on mechanical properties of high chromium cast iron with 0,5% niobium is examined. The hypoeutectic microstructure was altered by the heat-treatment, the matrix specimens became predominantly martensitic and there was secondary carbides precipitation. Niobium carbides agglomerated in petal-like and blade-like form. The 1000°C and 1050°C destabilized specimens presented the lowest wear rate values and highest matrix microhardness. The wear resistance was proportional to the matrix microhardness. Also, the size of the secondary carbides may have influenced wear rate. The wear mechanism was plastic deformation with microcutting and microploughing. Specimens which had more removed material presented a higher average roughness (Sa) and maximum values of peaks (Sp) and pits (Sv) tended to be lower as the temperature of the heat treatment increased. 

The present work evaluated the possibility of the use of an iron ore tail as an addition to partial replacement of Portland cement in cementitious composites. The iron ore reject was processed and calcined in the temperatures of 500 and 750 °C. For analysis, scanning electron microscopy (SEM), laser granulometry, X-ray diffraction (XRD), X-ray fluorescence, thermogravimetric analysis (TGA) were performed. The inorganic and calcined iron ore tailings had their pozolanicity evaluated by the Luxan method. After a characterization, the tailings were used in the preparation of mortar specimens with 10, 20 and 30% weight substitution of Portland cement. The composites were submitted to compression tests, with ages of 3, 7, 28 and 91 days, flexural traction test, with ages of 28 and 91 days, and water absorption and sulfuric acid attack, with ages of 28 days. The results of the Luxan test showed that the calcined tailings have pozzolanic properties. The results of mechanical properties showed a decrease in resistance, but with values above 30MPa for 30% substitutions at 28 days. In relation to the acid attack resistance, a replacement of the cement by the tailings showed excellent results. In general, the use of iron ore tailings instead of cement in mortars is a viable alternative for the immobilization of this industrial waste.

TRIP-assisted steels shows great potential and applicability in automotive industry due to their excellent combinations of properties that allow the production of thinner sheets without compromising the performance of components. The excellent combination of high strength, ductility and crashworthiness observed in TRIP steels is related to the multiphase structure present in these steels, produced usually by a thermal treatment consisting in intercritical annealing followed by isothermal treatment in the bainitic transformation range. In this work the effects of the intercritical annealing and bainitic transformation temperatures, as well as the holding time at isothermal bainitic temperature, on the microstructure and mechanical properties of a TRIP-assisted steel were analyzed. Evaluations were conducted in terms of optical microscopy, scanning electron microscopy, atomic force microscopy, X-ray diffraction, hardness tests, tensile tests and analyzes concerning the work hardening behavior of the material by four different methods: Hollomon analysis, work hardening rate, instantaneous n value and Crussard-Jaoul analysis. Higher austempering times favored the formation of bainite with lath morphology and allowed greater retention of austenite, resulting in lowerhardness values and yield strength. Reduction of austemperingtemperature favored the refinement of the bainitic structure and resulted in lower retained austenite fractions, but with a higher carbon content. In general, the use of a lower intercritical temperature promoted lower hardness values due to the increase of ferrite proportion. As for the hardening methods used, the analysis concerning the instantaneous n value was the most adequate for the deformation behavior evaluation of the studied steel.

In 2010 around 60 thousands tons of windshield scrap were genereted in Brazil. However, only 8% of it was recycled. The current windscreens are made of laminated glass, which consists of two layers of glass and a layer of polyvinyl butyral (PVB) polymer in between. Both glass and PVB are recyclable, but they need to be separated, which hinders the recycling of windshields. The most used method of separation between PVB and glass is shredding. However, this process does not recycle 100% of the materials, as some of the shards of glass generated during the shredding are attached to the PVB, that generates a residue that’s contains 30% of the initial windshield mass. The objective of this work is to develop a process for complete separation between PVB film and the windshield glass, allowing the recycling of glass and PVB with no waste generation. Flat laminated glass proof body were used to establish the process parameters. The process was tested for windshield samples of Fiat Palio car, samples of Pilkington and Saint-Gobain Sekurit windshield brands were tested. The method developed in this study consists of three stages: glass fragmentation, thermochemical attack and removal of the remaining glass fragments. As a result, the PVB film was obtained without glass fragments, which allows recycling of both the polymer and the glass.

The hardening of the Bake Hardening effect, BH, was studied in this work. This method is commonly used to increase the mechanical strength of steels in the automotive industry. Such a hardening mechanism depends on several parameters, such as the conditions used for the plastic deformation of the material, the temperature and time of the heat treatment, the chemical composition of the steel, among others. Considering this approach this work presented a Bake Hardening hardening study for the BH220 steel in the 1% preformed state after performing a stamping operation by analyzing the increase in mechanical strength. Samples were taken at 0 ° and 90 ° with respect to the rolling direction. Mechanical strength analysis was done using tensile techniques, with pre-deformations ranging from 0.4 to 3% and shear technique, with pre-deformations starting at 0.4% and reaching 11%. The results indicated a strong influence of the position of samples taken from the stamped product on hardening by hardening, as well as the plastic deformation applied to BH220 steel. Samples taken from the stamped product and tensile deformed in the 1% laminate condition revealed that the C direction of this product exhibited the greatest hardening by hardening. In the samples drawn at 90 ° DL, a differential mechanical behavior in traction and shear was observed: an increase of the BH effect was observed with the increase of the amount of pre-deformation while in shear, a decrease of the BH effect was observed with the increase of the amount of pre-deformation in shear. The responses of the material also varied by virtue of the mode of deformation applied. In terms of traction, the material was hardened, while in shear, there was softening for certain situations.

Superparamagnetic nanoparticles of iron oxides have been intensively studied for many industrial, environmental and biomedical applications. As biomaterials, nanoparticles have interesting properties for applications such as hyperthermia cancer treatments, contrast agents in MRI, controlled drug delivery, among others.In this project, superparamagnetic nanoparticles of iron oxides were synthetized by co-precipitation and coated with oleic acid in mono and bilayer. TEM analysis showed the particle size equal or inferior to 10 nm, magnetization analysis (VSM) proved the superparamagnetic character of the synthesized material and the results spectroscopies of Mössbauer and Fourier Transform Infrared (FTIR) confirmed the presences of phases and oleic acid molecules on the surface of the nanoparticles, recommending the potential of therapeutic use of nanoparticles of superparamagnetic magnetite.

The comprehension of the phenomena that occur during the machining allows the increase of the predictability of the process, leading to the increase of the productivity during the manufacture. Knowing the variables and the parameters of machining is very important to understand the behavior at the interface between the cutting tool and the workpiece. As an intermittent process, the milling exposes the cutting tool to cyclical variations of temperature and tension, generated by the rotation movement of the milling cutter during machining. This work has the objective of analyzing the wear of cutting tools in the front milling of parts with different geometries. These variations cause damages and wear, which can lead to fail and consequent end of tool life. Factors such as length and part geometry influence the number of tool inputs and outputs in the workpiece, increasing its wear. In this work, tests of frontal milling were carried out on two SAE 1045 steel bars with different geometries, keeping all cutting parameters constant. To differentiate them, channels were machined in one of them, respecting the total cut length, which was 300mm. After a defined amount of cut in and cut out, the tools underwent successive optical microscopy and mass gauging, in order to identify and characterize the present forms. Simultaneously, mechanical vibration signals were collected from the system composed of test specimens and cutting tools, with the purpose of ratifying the influence of the geometry of the parts on the evolution of tool wear. The data collected for each piece were arranged in graphs for a better understanding and comparison of the performance between the tools, and it was observed that the number of inputs and outputs of the tool on the part is the most relevant factor in the evolution of the wear. The tools used in the milling of the test pieces without channels were worn less than those used in the test pieces with channels.

The sterile rocks in mines are extracted from the pit and disposed in piles, generating environmental liabilities and considerable costs. The sericiticphyllite represents much of the sterile in the iron mines of the Ferriferous Quadrangle. In order to reduce costs and improve concrete performance, the cement industry has used supplementary cementitious materials (SCMs) partially replacing clinker in Portland cement. A type of SCM is represented by pozzolans, which are materials that when finely milled can react with the cement forming compounds with binding properties. The present work evaluated use of sericiticphyllite in partial replacement of clinker in Portland cement. For this, the phyllite was initially characterized by granulometric analysis by wet sieving and thermogravimetric analysis (TGA).Based on these results,a granulometric reduction was carried out in an industrial scale pendular mill and thermal treatment at four different temperatures in an industrial rotary kiln, aiming to transform the little reactive phases of the phyllite into more reactive phases.The products were characterized by scanning electron microscopy (SEM), X ray fluorescence (XRF), laser granulometry (LG) and Xray diffraction DRX. For the characterization of the material as a pozzolan, hydration heat tests, electrical conductivity in sodium hydroxide solution and determination of the Portland Cement Performance Index were performed.New cements were produced by replacing 25% of a cement with reduced additions by milled phyllites with and without heat treatment. The properties of these cements were evaluated by mortars compressive strength tests at the age of 28 days as prescribed by the Brazilian cement standards. To complement the analysis, tests of flexural strength at 28 days, dry density, void ratio and water absorption were performed.The sericiticphylliteFRX composition indicated the oxides SiO₂, Al₂O₃ e Fe₂O₃ and the XRD analysis indicated the presence of kaolinite, quartz, goethite, hematite and muscovite in the form of sericite, minerals formed predominantly by the oxides previously mentioned. The replacement of the Portland cement clinker by phyllite reduces the heat generated and dissipated in the hydration reaction of the cement pastes, reducing the porosity and increasing durability. The results of the electrical conductivity in sodium hydroxide solution and the determination of the Performance Index with Portland Cement showed that the phyllites heat treated at 700ºC and 900ºC have good pozzolanicity and meet the requirements of NBR 12653 for pozzolanic materials for the production of Portland cement. The milled sericiticphyllite with or without heat treatment has no influence on the flexural strength and causes a slight increase in the water absorption, it is believed that this absorption is due to the greater need of dewatering water caused by the increase of the surface area of the system due to the reduced granulometry of the phyllites when compared with the cement.All the phyllite samples tested can be used in pozzolan Portland cement compositions (CP IV) of strength class 32, according to NBR 5736 (ABNT, 1991).

The mineral aggregateshasinterestingcharacteristics for severalapplications, theirextractionandprocessingdependonthe mining processes, wherehigh wear ratesoccur. Wear as thevariablethatrepresentscost must beminimized in anyway, thusincreasingprofitabilityindicesanddecreasingmaintenance, therebyprovidinglongermachineandequipmentlife. In thiswork, a studywascarried out onthewearofmetalliccoatings, obtainedcommercially, being: high abrasionresistantlowalloyboronsteelswithdifferenthardness classes (AR) andhardfacingrichchromiumalloydepositedbywelding. Both coatequipment in thestagesof mineral extractionandprocessing. The coatingswereevaluated for theirmicrostructure, hardnessandchemicalcomposition. Abrasiveweartestswereperformedaccordingto ASTM G65 (Rubber Wheel) withquartzsandnumber 50, andtheabrasionresistancepropertiesofeachtestedcoatingwereanalyzed. The performances ofthecoatingstestedwereverifiedbymeansofthemassloss in theabrasivetestandbyscanningelectronmicroscopy, where micro wearmechanismswereidentified. The micro wearmechanismsobservedwererelatedtothemicrostructuretypeandhardnessofthecoatings, varyingbetweenmicro-cuttingandmicro-cracking. The highhardnesshardfacingrichchromiumalloypresentedhigherabrasiveresistancethanmartensiticlowalloyboronsteels, butpresenting a brittleandcrackingbehavior. Thiseffectcanaffect material performance underimpactoperatingconditions

The Light Steel Frame (LSF) is an alternative building system to the traditional building system using reinforced concrete, where prefabricated galvanized steel sheets are used for construction of houses and small buildings. The steel sheets used in this process undergo through mechanical forming processes, as folding, to acquire the needed format for assembling the structures. The corrosion behavior of galvanized sheets, however, can vary according to modulus of deformation that the part has suffered, that is, different regions of same part can presents a different corrosion behavior. This study has as objective evaluate the corrosion resistance of galvanized steel sheet after forming by folding in comparison with the corrosion resistance presented by non-folding samples. To carry out this work, was analyzed 25 galvanized steel samples used to build the metallic structure of LSF construction system. The samples were previously characterized by measuring the thickness of coating and microstructural analysis of coating. The samples were separated in five groups, where one group didn’t suffered forming and, on other groups, the samples were folded forming angles of 30°, 60°, 90° and 120°. After that, all the samples, including non-folded, were submitted to corrosion test using a galvanostatic / potenciostatic. The corrosion analysis were carried out by comparing the corrosion potential Ecorr showed by the samples in different forming situations. The results has showed that folded samples has presented higher corrosion potential than non-folded samples, confirming the hypothesis that mechanical forming influences on the corrosion resistance of material. Also, the results has showed that the percentage of deformation suffered by the coating have influence on the acceleration of corrosion process.

This study is an integral part of a broader project aimed at the construction of a hydrocyclone for the removal of high levels of oil in water in order to allow the replacement of gravitational separators on offshore platforms. The materials selected for application in this industry must be of high mechanical and corrosive strength due to the complex processing characteristics. The stainless steel duplex UNS S31803 is a commercial steel, which has been widely used for such applications. In this work, the objective is to evaluate the effect of the conformation and welding processes, in the microstructure and corrosion resistance of the material. The plates duplex steel UNS S31803, 1,8mm, were ceded by Aperam South America. The sheets were cold conformed by folding at a 90 ° angle. After the folding, the pieces received a weld bead by simple deposition by the TIG -Tungsten Inert Gas welding process, with a thermal input of 0,4 kJ/mm², realized in the ESAB. For the analysis of the material in the three studied conditions, material as received (MR), shaped material (MC) and shaped and welded material (MS), characterization tests were performed (MO/MEV), X-ray diffraction, volumetric analysis of the ferritic phase with the aid of a ferritecope and by image analysis by ImageJ^®. For analysis of the corrosive properties, cyclic potentiodynamic polarization tests were applied to the material under the three conditions studied. The results showed that only in the conformed material, there were indications of phase transformations induced by cold deformation (γ → α'). For the deformed and welded material, the volumetric fraction of ferrite in the heat-affected zone increased significantly. No formation of the sigma phase was observed, but there was precipitation of chromium nitrides in the ferrite due to the high cooling rate after welding. In the cyclic polarization tests, it was found that the welding conditions imposed on the material, after the conformation, impaired its performance in terms of its corrosion resistance, affecting the regeneration of the passive film.

The industrial sector seeks in all its processes ways to optimize the production of mechanical components, seeking still improvements in the physical and mechanical properties of the materials. EDM is a process that has been studied because it allows some superficial modifications to be produced, at the same time as the part is machined. Previous studies have demonstrated the feasibility of machining metallic materials by EDM, immersed in aqueous solution containing urea, obtaining a surface enriched with nitrides which increases the hardness of the part, but none showed uniformity of the machined layer. In this work, the feasibility of nitriding samples of AISI 4340 steel by the EDM process by penetration using dielectric fluid as deionized water and urea was studied. As electrode tool were used graphite and electrolytic copper. The operating parameters of the EDM machine were adjusted in such a way as to allow the formation, dissipation of a plasma channel and maintenance of the uniform surface layer. The influence of the tool electrode on the machining performance, the microstructure and the uniformity of the nitrided layer were analyzed through material removal rate (TDM), wear rate (TD) and relative volumetric wear (DVR), microscopy as well as an X-ray diffraction analysis to prove the formation of nitrides on the machined surface. The analyzed images confirmed the formation of the rectified and nitrided layers. The roughness of the samples after machining and in the successive polishing steps were evaluated where 10μm thicknesses were obtained in the machined surface. There is a decrease in the concentration of nitrogen from the surface. It was performed microhardness where it was verified that there was gain in the hardness. By means of these analyzes it can be concluded that the copper electrode presented in the sample a greater uniformity thus allowing the removal of the recast layer.

One of the biggest environmental challenges today is reducing the emission of carbon dioxide (CO2) into the 
atmosphere. It is one of the greenhouse gases, being generated mainly through the burning of fossil fuels.
 Its capture has been the subject of countless researches and new technologies, as well as distillation, 
gas / solid reaction, adsorption, etc. This work proposes the production and study of the adsorptive 
characteristics of the hydroxyapatite (HAP) synthesized using as the calcium source chicken eggshells. 
Hydroxyapatite is not widely used as a gas adsorbent and is nowadays its main application in the biomedical
 sector due to the similarity with the mineral phase of human bones. The chicken eggshell, being a calcium 
carbonate-rich waste and of no commercial value, appears as a source of calcium carbonate for the synthesis
 of HAP. For the preparation of the eggshell, hygiene was initially carried out for removal of organic material 
and some unwanted impurities in the process. The eggshell was submitted to the Thermogravimetry (TG) 
test where the ideal decarbonation temperature was determined: 805ºC. Calcination of the shell for 
conversion to calcium oxide was carried out using muffle type alumina crucibles. The result of the X-ray 
Diffraction (XRD) test for the egg shell after calcination was satisfactory. The synthesis reaction generated 
a compound with some crystals of hydroxyapatite and calcium hydroxide. After calcining the compound 
was reexamined by XRD and the result was also satisfactory, being found peaks confirming the presence 
of hydroxyapatite. The adsorption tests were carried out with carbon dioxide at levels compatible with 
those found in industrial chimneys, where there is the burning of fossil fuels. Quantifications of the initial 
levels of CO2(14 ± 1%) were made with adsorption evaluation in cycles of up to 180 minutes at room
temperature. The tests were made by varying the mitigating material in calcined and non-calcined, and 
in environments with or without light. Comparison of the adsorption results of the calcined HAP and 
non-calcinedHAP showed a higher efficiency of the non-calcined HAP in the light environment. In this 
scenario there was adsorption of approximately 44g of carbon dioxide to each gram of mitigating material.

The hot recycling of Reclaimed Asphalt Pavement (RAP), as material to compose asphalt mixtures, aims to reinforce the sustainability concept of the asphalt paving area, promoting the mitigation of damages caused by oil and natural aggregates extraction. RAP is a residue, which is produced in abundance during the maintenance of asphalt paving, but it is still little used in hot asphalt recycling mixtures. The main objective of this research was to study the performance of hot recycled asphalt mixtures with 100% of RAP, for cold application in pothole. In the experimental research, before the materials dosages, the physical characterization of RAP was carried out. The results of granulometry and bitumen extraction tests carried out for the RAP were approved for use in the asphalt mixture dosages, since they presented the characteristics established by the reference curve of DNIT ("C" range). The addition of Re-refined Engine Oil Bottom (REOB) in the hot recycled asphalt mixtures had as function to maintain the workability of the mixture at ambient temperature and provide rejuvenation of the properties of the aged binder present in the RAP. The mechanical characterization was made with compressed samples, which were molded by the Marshall methodology, to perform the tests of diametral compression strain and Marshall stability and fluency. The results obtained in this work confirmed the research proposal, which were presenting dosages of hot recycled asphalt mixtures with 100% of RAP and addition of REOB, petroleum asphalt cement (bitumen), rubber powder and lime, with good workability and mechanical strength. The developed mixtures characterized as an alternative material in pothole maintenance, with cold application.

The literature shows that aluminum foams have a wide range of applications as structural material mainly in the aeronautical and automotive industries due to the physical properties of thermal and acoustic insulation, as well as the ability to absorb mechanical stresses of compression and / or torsion, among other characteristics such: weight reduction and energy saving. This work aims to contribute to the studies related to parameters to obtain aluminum foams via the route of powder metallurgy using the cold conformation mechanical compaction. A drawn SAE 1045 steel mold was machined and heat treated (quenching and tempering) in the quest for surface hardening required to withstand the high loads used in the uniaxial compression of the powders (aluminum and titanium hydride) used in the proposed experiments matrix. The raw materials consisted of aluminum powder (Al), powdered titanium hydride (TiH2) as foaming agent and zinc stearate as the release agent. Fifteen green test specimens, divided into 5 batches, denominated A, B, C, D and E, with expander concentration 0.00%, 0.80%, 1.00%, 1.20% and 1.50% respectively. A priori, compaction occurred at a pressure of 350 MPa, after the green CPs were sintered at a heating rate of 16 ° C / min to the temperature of 710 ° C in an inert atmosphere, argon, remaining at this temperature for 8 minutes. The physicochemical characterization of materials and CPs were used to determine the particle size, the Thermogravimetric Analysis (DTG) specifically for titanium hydride, in order to verify the release temperatures of X-Ray Diffraction (XRD) for the verification of crystalline structure, X-ray Fluorescence Spectroscopy (EDX) for analysis of chemical composition, and finally Scanning Electron Microscopy (SEM) for analysis of surface morphology proof bodies. The following foaming processing parameters and the mold have proven to be effective. The materials produced presented values of relative densities between 0.44 and 0.73, with the volume increasing up to 126%, for the studied parameters of compaction with 350MPa, heat treatment 710ºC / 8 min in inert atmosphere.

The nitriding by electrical discharges is emerging as a low cost alternative that promotes the junction of the machining process by electrical discharges with the surface treatment in the same equipment at the same time. The dielectric fluid used in the process, an aqueous solution containing nitrogen, undergo transformations due to the thermoelectric complex process that took place during the machining process, forming iron nitrides.
Throughout the development of the electrical discharges nitriding process (EDN) emerged many questions. One is the influence of urea quality used in the aqueous solution of the dielectric fluid as the nitrogen source for the nitriding process. This study aims to evaluate the interference of urea quality in the EDN process using AISI 4140 steel samples. Therefore, were used three types of urea: fertilizer, pharmaceutical and analytical standard. The nitriding was performed on electrical discharge machine (EDM) per penetration, machining steel samples immersed in aqueous solutions of urea with concentration of 20 grams per liter and using copper or graphite electrodes. There was the formation of two main layers in the process: remelted zone (RZ) and the heat affected zone (HAZ). The thickness of these layers was evaluated by optical microscopy, and also evaluated the Vickers microhardness. The results showed that the category of the urea used influences the thickness of the nitrided layer. For HAZ, the analytical grade urea, associated with copper electrode, propitiated the formation of a layer with a thickness almost double when compared to the experiments that used fertilized urea. No significant variation in the thickness of HAZ was observed when graphite electrode was used. The values of hardness did not show expressive variations. The different categories of urea used did not significantly interfere on the material removal rate (MRR) since the electrical conductivity of the prepared aqueous solutions remained low.

In this work, sulfonation reactions of polystyrene (PS) residues (disposable cups and expanded polystyrene - EPS) with different degrees of sulfonation were carried out. Homogeneous sulfonation reactions were carried out using acetylsulfate as a sulfonating agent and heterogeneous sulfonation used sulfuric acid as the sulfonating agent. The characterization of the products was done using infrared spectroscopy, solubility tests and inductively coupled plasma optical emission spectroscopy (ICPOES).
Infrared spectroscopy revealed that the reaction was efficient and all the starting materials tested were successfully sulfonated, and EPS was chosen as the substrate for further reactions varying the degree of sulfonation. Solubility and ICPOES have shown that by changing the synthesis conditions it is possible to achieve different degrees of sulfonation of the products. Partially sulfonated polystyrene (PSS) obtained in the reactions were selected according to the sulfonation grades and tested as superplasticizer additive for mortars and concretes, and their flow and compressive strength were evaluated.

Organic solar cells (OSC) are considered the most recent generation of photovoltaic devices. They are flexible, lightweight and can be processed through solutions. Moreover, the possibility of abundant materials usage makes them useful in a series of new applications in the photovoltaic field, like in portable and flexible electronic devices (e.g. battery chargers, screens) and devices integrated to textiles (i.e. e-textiles). Although a lot of studies are being conducted to understand the mechanisms of degradation in OPV devices, recent researches already extended lifetime to about 2-3 years by using appropriate layers of barriers. This makes necessary a set of accelerated studies to predict the lifetime of the OPV modules, considering the specific characteristics of this new technology and that the number of factors that affect the performance of these devices is greater than in traditional inorganic devices. Creating specific standards to evaluate OSC stability and lifetime involves performing a variety of tests, in many laboratories and by different devices, all of them following a set of stablished protocols. The accuracy of the results depends on the quantity of reported data, which is still incipient. According to the literature, an OSC can degrade because of chemical-nature processes – that suggests that an Arrhenius model (i.e exponential decay model) can be used for study. In this work, an accelerated test, using temperature degradation, was conducted to estimate the lifetime of OSC cells, based in the “T80 model” which measures the degradation until 80% of the initial value is reached. Unlike other works, this method evaluates degradation simultaneously in three different temperatures. Furthermore, a portable and low-cost apparatus, scalable to bigger projects, is presented. The achieved results indicate that the OPV cells degrade considerably in 85º C and 100º C, since the beginning of the study (1^st week). Only one of the cells degraded in 70º C could keep the degrade tax of the PCE parameter under 20% after 1008 hours (42 days) of analysis, while the remaining cells presented a good performance, considering the I_SC parameter.

Thermoplastics have been gaining more and more space in the market, especially in the automobile industry, where its consumption has grown over the years. Commercially the polypropylene (PP) stands out in its excellent mechanical, physical and chemical properties. The objective of this study was to evaluate the quality of the solvent, sorbitol, functionalized zinc oxide nanoparticles, recycled ABS and PP and PS cups, applying a long processing time in order to simulate reprocessing. The techniques of X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetry (TG / DTA), scanning electron microscopy (SEM), x-ray fluorescence (FRX), infrared spectroscopy, And dynamic-mechanical analysis (DMTA) were used to characterize the materials and mixtures, parametric parameters to define the best aid. Initially it was chosen to work with two degrees of PP, until a definition of pure PP as of interest. The processing of pure hair and all components and blends followed the same pattern. Four processing times were done, simulating a reprocessing, in addition to the contents of 5,10 and 15% of additive. These materials were extruded in a HAAKE extruder, which are important data on the behavior of the material. Possible degradation during processing was evaluated via mechanical tests. The additives added significant properties to the increase in energy peak, energy and influences on compound strength. As expected the commercial additive, sodium benzoate significantly improves the thermal and mechanical stability of the material. It was observed that, ABS significantly improved thermal stability, and recycled PP and Ps improved the rigidity of the material. It was also verified that, reprocessing by up to four times, did not significantly affect the quality loss of the material contributing to the improvement of the thermal stability of the mixtures, besides a better mechanical performance compared to that presented by the pure polymer.

Due to the large amount of residue that has been generated in the ceramic industry, a way to mitigate the environmental impacts generated by the waste disposal during the porcelain production process has been studied. Among the various types of ceramic coatings, porcelain has stood out due to its technological production process and excellent technical characteristics. The purpose of this work was to study the main characteristics of porcelain tile and a detailed physicochemical characterization of the atomized mass (MA), the residue generated in the polish of the porcelain (pie), and the raw materials used in the production of porcelain tile by means (XRD), X-ray fluorescence (EDX) and Scanning Electron Microscopy (SEM). According to the data obtained, it can be stated that the chemical composition of (Residue) and the present phases are similar to the atomized mass (porcelain), which makes possible to reuse it as a raw material in the ceramic industry. After the characterization, new ceramic mass formulations were proposed, using or not the residue obtained from the porcelain polishing phase in which the formulations were based on triaxial standard compositions of ceramic materials, which had the best mechanical performance according to specific bibliography. The formulations studied were divided into M series, C series, C3 series and MR series. They were submitted to different firing cycles ranging from room temperature to 1245° C, in order to evaluate the best physical and mechanical responses. The best formulations of these 4 series were put in an optimized firing cycle in a ceramic company. Fifteen specimens with dimensions of 20,0X60,0X9,0mm, uniaxially pressed at 54MPa, were produced for each formulation. After sintering, the samples were characterized by linear retraction (RL), volumetric retraction (Rv), water absorption (AA%), apparent density (Dap), apparent porosity (Pap). The bending test of the samples followed the standard NBR 13818: 1997. The results obtained showed that from the M series the M4 formulation produced the ceramic material with best performance, it obtained a flexural strength of 32.63 MPa and a water absorption of 1.68%. From the C series, it was the C3 that presented a better result of apparent density (5592,78 kg m-3) and water absorption (1.44%) and greater mechanical resistance (41,27 MPa). The series MR to MR3 with 15% by weight of waste was the best performance with water absorption (5.53%) and higher mechanical strength (12.46 MPa). Finally, in the C3 series, the best performance was observed in the C3C formulation in mechanical strength (34.56 MPa), which is the maximum point, which indicates that a better packaging of particles. When analyzing the results of the formulations of better mechanical performance that were submitted to the industrial furnace, it is observed that the firing cycle influenced directly on the possibility of reusing or not the residue generated in the polishing of the porcelain tile and that the three formulations tested, even if not classified as porcelain tiles, have presented excellent performances and are classified as other ceramics.

Effluents contaminated with heavy metals from agriculture, mining and industrial activities are highlighted in the waste treatment field due to their high toxicity. Among many possible methods to treat this type of effluent, electrocoagulation is a versatile technique that generates smaller volumes of waste, when compared to other treatment techniques. In this work, a pilot unit for heavy metal effluents treatment using the technique of electrocoagulation was constructed. Operational parameters were investigated for the evaluation and determination of the best conditions for the process, looking for lower operational costs, lower electrodes consumption and better solid flocculation. The best results were with sodium chloride in 2000mg/L concentration, and 4 electrodes (2 pairs). The heavy metal removal tests were evaluated by determining the residual concentration, thus indicating the percentage of removal of these elements by atomic absorption spectroscopy. The zinc and copper removal were higher than 93% and 99%, respectively, sufficient to attain the maximum concentration for discard. The sludge generated by the electrocoagulation process was characterized by X-ray diffractometry, X-ray fluorescence spectroscopy, scanning and transmission electron microscopy, laser granulometry and supercicial area analysis. It was noted that all the solids obtained are monophasics and nanostructured, similar to magnetite, allowing future studies about using that procedure for rote synthesis. The average particular size was between 18nm and 36nm, the average particular aggregate size was about 205nm. The large superficial areas of the solids (between 32,5m²/g and 43m²/g) and the heavy metal presences allow to use them in adsorption and catalysis process, respectively.

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This study attempts to propose the development of fertilizer inputs from the mitigation process of greenhouse gases from chimneys of thermoelectric,plants (TEP) coal or natural gas. To achieve this end, the catch by physical adsorption pressure balanced technology will be used (PSA). After immobilization of the effluent CO2, chimneys eiiminated by using a compound of beta-tricalcium phosphate (13-TCP), hydroxyapatite (HA) and amorphous calcium phosphate (ACP) and subsequent incorporation into N2 and K, the techniques will be improved agglomerating the product of these two constituents saturated with CO2.The research will be conducted in order to optimize structural parameters of post particies of calcium phosphate saturated with CO2 and functionalizing with chemical elements (K and N2) its application in agriculture, seeking to develop materiais for pH correction purposes of acid soils and maintenance of soil fertility. The FCT will be donated in sufficient quantities for use in this research by companies already contacted. Ailied to the exploratory studies of adsorption of retained gases (quantification of CO2) will develop studies of agglomeration / pelletizing, and release of macronutrients, seeking explanations of the interactions of surfaces and / or interfaces of the particuiate matter in the soil. The modified NPK fertilizer processing will be conducted by mixing the saturated FCT powder with ammonium nitrate powders or urea (nitrogen source) and potassium chioride, becoming a possible siow-release fertilizei, able to release their retained components in its crystal lattice directly on the plant roots 'or soil, promoting a gain in crop management. The physicochemical characterization phase calcium phosphate (FCT) will be developed with the use of equipment of laboratories of DEMAT / CEFET-MG: MEV, DRX, FRX, laser diffraction (CILAS), surface area analysis (BET) and Thermal analysis (TGA). The FCT residue with CO2, N2 addition and / or K applied to the corrective pH fertilization when there is the possibility of correcting the soil once. This practice is to apply the seed furrows or haul a quantity of P, N, K and Ca so as to accumuiate over time, reaching over and after some time the availability of these nutrients in the desired proportions.

Titanium and its alloys are widely used in the biomedical field as implants and orthopedic prostheses
 due to their behavior in terms of biocompatibility, corrosion resistance, as well as other mechanical 
properties. Under normal conditions the titanium is covered by a natural oxide film of 1.5 to 10 nm 
thickness, composed mainly of TiO

₂

, which improves the biocompatibility property, resulting in a more
 favorable biological response of the surrounding tissue in relation to the prostheses of other metals. 
However, after allocation of the biomaterial in the physiological environment, reactions in this interface
 may cause local or systemic effects due to characteristics such as surface energy, composition,
 structure, roughness and topography, as well as local conditions of the tissue. This phenomenon 
can occur because the anatomic-physiological response can be affected, besides the superficial
 chemical properties, by the superficial morphology and roughness of the metallic biomaterial.
 In this work the Ti-6Al-4V alloy had its surface modified by electrochemical processing with the 
objective of improving the resistance to wear or corrosion, increasing the biocompatibility through 
external aspects, such as: TiO2 film thickness, wear coefficient, microhardness and roughness, 
making it more effective to biofixation and adhesion of the biomaterial to the bone tissue.
The physico-chemical and biological characterization involved scanning electron microscopy, 
electron diffraction spectroscopy (EDS), X-ray diffraction, X-ray fluorescence, micro-hardness vickers, 
abrasion, roughness and cytotoxicity, which is a requirement for biomedical application materials. 
This evaluation aimed to determine the combination of process variables that positively influence 
the characteristics of the formed film, and thus contribute to the electrochemically coated products 
offer greater reliability in their application.

Developed in the last years, the Electric Discharge Nitriding (EDN) process has become a promising way to simultaneously process and nitride the surface of metallic materials. Low density, good tensile strength (comparable to many bonded steels) and excellent corrosion resistance are properties that allow the application of titanium and its alloys in the aerospace, naval, chemical, automotive and medical industries. However, it is rarely used as sliding parts due to its low resistance to abrasive and adhesive wear mechanisms. The thermochemical treatment of nitriding can solve this restriction. The objective of this work was to study the nitrided layer in the Ti6Al4V titanium alloy by means of the NDE process, using a solution of deionized water and granulated urea as a source of nitrogen as the dielectric fluid. A penetration electric discharge machining machine was used in the process. Copper and graphite were used as materials of the electrodes tool. The machinability of the Ti6Al4V alloy was evaluated to the parameters: material removal rate, wear rate and relative volumetric wear. To characterize the nitrided layer were made optical microscopy, where the nitrided layer of 276 μm and 249 μm was verified using copper electrode and graphite, respectively. The Vickers microhardness measurement was performed with a 90% hardness increase compared to the base material. The formation of nitrides on the surface was evaluated by means of x-ray diffraction. Metallographic images of the cross section of the surface showed the formation of the nitrided layer. Sliding wear tests were carried out, pin to disk for evaluation of the wear resistance, in this test the higher wear resistance of the nitrided samples by the NDE process was verified in relation to the titanium alloy sample without the NDE treatment. In addition, abrasive and adhesive wear on the tracks generated by the wear test were observed through scanning electron microscopy.

The C-Mn steel pipes are commonly used as a coating on the pipes of the oil wells of the oil & gas industries since when they started their activities. Several requests are required in those pipes, but the main one is the severe resistance against corrosion by hydrogen sulfide (H2S) or carbon dioxide (CO2). A direct application would be to use steel pipes made of high-alloy (Ni, Cr) which have high added value and acquisition costs become, for production, unviable. The option to increase the resistance against corrosion is the use of overlay techniques at the metal coating of the C-Mn steels using nickel superalloys and/or stainless steel (NAFFAKH; SHAMANIAN; ASHRAFIZADEH, 2008). The metallic coating used is an INCONEL® 625 nickel superalloy, which has good corrosion resistance in harsh environments such as H2S and CO2 (CARNEIRO et al. 2003; KITTEL et al, 2010; WANG et al, 1013.). The deposition of the coating by the welding process is a complex procedure and generates a thermally affected zone (TAZ) which in most cases is detrimental (SILVA et al., 2012). Microstructural and microhardness characterization of the system C-Mn steel/ INCONEL® 625 coating was taken before and after performing five heat treatments simulating possible industrial routes, checking among these, the most promising for industrial applications. The results show that the steel used has good hardenability, but after deposition of Inconel® 625 was observed a harder zone, called the TAZ, withbainite formation in the steel and the presence of molybdenum and niobium carbides between the dendrite coating. Some heat treatments performed deteriorated microstructure and hardness of steel or were not able to eliminate the TAZ. However some thermal treatments, showed good results in the preservation of the original features of the steel and the coating, eliminate the hard zone (TAZ), with feasible time being framed to the reality of production processes.

The iron oxy-hydroxide akaganeite (β-FeOOH) was synthesized, as well as a magnetic-adsorbent composite by combining akaganeite nanoparticles (β-FeOOH) with magnetite nanoparticles (Fe3O4). Because of its high affinity for arsenic (As), this material has great potential for use in decontamination processes of aqueous environments via adsorption. The akaganeite was previously synthesized by hydrolysis of FeCl3.6H2O and characterized. The characterization by EDX showed a
6.5% chloride content, which is consistent with the literature. With FTIR spectroscopy was possible to identify all bonds-vibrations characteristics of akaganeite. The confirmation of obtaining the β-FeOOH phase was also made by XRD-Rietveld Refinement, in which was determined a crystallinity of up to 99.0% for akaganeite. The images obtained by TEM showed the typical morphology of akaganeite:
somatoids with a length of about 200 nm and a diameter of approximately 50 nm. The Raman spectrum showed a profile of peaks characteristic of β-FeOOH. The akaganeita presented a specific surface area of 21 m2/g, determined by BET and a PZC equal to 7.02. The composite (β-FeOOH/Fe3O4) was synthesized by coprecipitation of magnetite nanoparticles in the presence of akaganeite, i.e., the previously obtained akaganeite served as substrate for the synthesis of magnetite, in which was used FeSO4.7H2O and FeCl3.6H2O as precursors. The composite was characterized by FTIR, DRX- Rietveld Refinement, TEM and PZC, confirming the presence of both β-FeOOH and Fe3O4 phases. The characterization techniques DRX, FTIR and TEM showed the predominance of akaganeite phase in the composite, 73,9% determined by Rietveld refinement. Microscopy revealed the typical morphologies of akaganeite (somatoidal and nanorods) and of magnetite (cubic), with an average crystallite size estimated at 100-200 nm in length and 10-50 nm wide in diameter to akaganeite and 5-15 nm for magnetite. The PZC value of the composite was 6.99. Adsorption data collected in akaganeita and in the composite fit better to Langmuir model. These data also confirmed that the magnetic composite shows good potential for removal of As (III) and As (V) as the maximum adsorption capacity was 8.8 and 8.1 mg/g for As (III) and As (V), respectively, reaching 87% removal of As (III) and 96% removal of As (V) in low contaminant concentrations in solution. Thus, the composite can be considered an effective adsorbent for arsenic removal of trace concentrations in aqueous media. As the adsorption capacity was similar for the two species in the composite, it is considered that the oxidation stage of As (III), normally used in conjunction with other contaminant removal processes, can be avoided. The presence of magnetite
nanoparticles in the composite did not compromise, significantly, the performance of akaganeite as arsenic adsorbent, but introduced the great advantage of magnetism on the solid-liquid separation, making it very attractive for application in adsorption processes on an industrial scale. Therefore, using the "magnetic akaganeite" in batch operations and magnetic separation it’s possible to optimize the removal of arsenic and reduce operating costs.

Reclaimed Asphalt Pavement (RAP) when recycled hot pressed and give rise to a material with characteristics that may be suitable for making tiles. Tile is defined as a coating for floors or walls to run finishes in buildings. The main objective of the research is to contribute to the technical feasibility study of the Reclaimed Asphalt Pavement using recycled hot for making recycled asphalt tiles for use in construction. The recycled asphalt tiles can contribute to preserving the environment, have low cost and present features that can provide adequate durability. For this study we analyzed the manufacturing processes, physical and mechanical tests and pathologies of the RAP tiles, hydraulic and ceramics, aiming to optimize the development of recycling RAP. Molding of the test specimens RAP was characterized, heated and compressed to form blocks that were later cut forming the recycled asphalt tiles. Before pressing the blocks, characteristics such as temperature and pressure were observed in order to ensure more efficient processing of the tiles. The tests performed on specimens were absorption, resistance to mechanical strength, resistance to abrasion, degradation climate chamber and adherence. The recycled asphalt tiles exhibited satisfactory values in most tests. On the presented results, it can be concluded that recycled asphalt tile may be viable from a technical point of view.

A cobalt oxide-based catalyst recovered from cell phone Li-ion batteries supported on a ceramic substrate was developed in this work. Both active phase and support were from material recycling. Analysis by XRD and XRF showed about 99% of cobalt in the phases Co3O4, CoO and LiCoO2 for the active phase and phases similar to those of cordierite for the ceramic support. Evaluations of catalytic performance and reaction conditions by cracking soybean oil were performed. Characterization of the products by FTIR, TG/DTA and CG showed the inactivity of the ceramic support to the reaction and indicated that any alteration in the visual, thermal and chemical aspect of the cracked oil was exclusively due to the catalytic efficiency of the catalyst. They also pointed out that catalyzed reactions under temperature conditions around 322°C, 332°C and 355°C and times of 4 and 8 hours were able to convert the soybean oil into synthetic gaseous fuel and that the temperature of 355°C and the time of 4 hours was the best condition for this. Concluding that the developed catalyst proved to be efficient in producing fuels from renewable sources at low temperatures and over a relatively short period of time, leading to a significant energy reduction in the process, reducing costs of +processing and production of alternative fuels.

The utilization of the energy generated by the Sun, both as a source of heat and light, is today one of the most promising energy alternatives. Among the many applications of solar energy, the direct generation of electricity by photovoltaic effect presents itself as one of the eco-friendliest ways to generate electricity. The photovoltaic modules are subject to action of pollution, dust and other natural factors, which make difficult or reduce the incidence of solar rays in photocells harming its efficiency, what is clear when we compare the electrical measurement between PV modules with soiling and cleaned. In this work, besides the simulation of soiling in different photovoltaic modules, it was studied the influence of dirt accumulation on the performance of a photovoltaic module installed at CPEI-CEFET/MG-campus II that is generating electricity by photovoltaic conversion, without cleaning maintenance for more than eight years. Important to note that in this case, the module was removed from the photovoltaic generator in normal working conditions and it has been characterized regarding its efficiency, before and after cleaning. The accumulated dirt was characterized regarding its chemical composition, biological and mineralogy. the dirt is composed by great amount of organic matter due to biofilm, which causes reduction in the transmittance photovoltaic modules cover and hinders the maintenance of cleanliness. The comparison between the module surface, before and after the cleaning process showed the importance of studying and identification of the differences between the electrical parameters that are affected by dirt, as biofilms that resist to the natural cleaning generating a loss of more than 10% of the electric power during on photovoltaic conversion. With the objective of facilitating the characterization and comparison between the electrical parameters, it was developed a test instrument and measurement system in order to calculate and store the data of the current and voltage curve (I-V). The obtained data were analyzed and are presented in this dissertation. This research aims to assess the effect of dirt and to identify the characteristics of the existing dirt, contributing to the improvement of efficiency of the energy radiated conversion by the sun into electrical energy as well as the reduction of maintenance costs of photovoltaic panels.

High strength steels are widely applied in structural parts that require properties such as tensile strength, toughness and abrasive wear resistance. The wear is one of the most common failures that occur in mechanical components. Low-alloy steels offer combination of price and performance that make them competitors of highly alloyed steels, cast iron and ceramic. This work was proposed according to the development of new classes of steels to minimize the effects caused by abrasive wear. The main goals of it are to get four multiphase structures (bainite, ferrite and constituent MA) for the steel 0.26% C-1.13% Mn-0.92% Si-0.72% Cr-0.29% Mo-0 18% Ni-0.17% Cu and compare their mechanical and tribological properties with a structure consisting of tempered martensite, a typical structure of wear resistance steels. It is also intended to evaluate the influence of volumetric fraction of retained austenite in wear resistance through the TRIP (transformation-induced plasticity) effect. The heat treatment temperatures selected were 820, 860, 900 e 940°C for 10 minutes, followed by rapid cooling to the bainite holding temperature of 400 °C for 5 minutes and finally cooling in water. The tempered martensite structure was obtained by austenitization at 940ºC for 10 minutes followed by quenching in oil and tempering at 250°C for 2 hours. Optical microscopy (OM) and scanning electron microscopy (SEM) were used to analyze the obtained microstructures. The amount of austenite was measured by the technique of integrated intensities of X-rays and other constituents by counting points. To evaluate mechanical properties after heat treatments, hardness tests and tensile tests, at room temperature, were carried out. The abrasive wear resistance was evaluated by microabrasion tests. The multiphase structures showed superior ductility to the tempered martensitic structure, but had lower hardness and tensile strength. However, the results of microabrasion tests exhibited that these structures have superior wear resistance to the tempered martensite structure.

Calcium phosphate-based adsorbents are not very common for use in CO2 capture systems. In view of this fact, this paper proposes the study of a ceramic compound of calcium phosphate-based named Calcium Phosphate Three Phase (CPT). The term “three-phase” refers to the existence of three distinct phases in their structure, namely: Amorphous Phosphate Calcium (ACP) - amorphous phase; phosphate Tricalcium (β-TCP) and hydroxyapatite (HA) - crystalline phases. The CPT is an attempt to improve the calcium phosphate adsorbents formed at low temperatures (below 400°C). This research’s main objectives were to synthesize and characterize the CP3P powder, in addition, to simulate the CO2 emission conditions of a chimney, comparing FCT behavior exposed to CO2 in a fluidized bed with the ACP behavior described in previous study's results. For the tests, the fluidized bed system that injects CO2 and compressed air in specific proportions had been improved, simulating gasses’ emissions released by burning coal from industrial chimneys. The equipment used was developed considering the methodology Conceiving, Designing, Implementing, Operating - CDIO being composed of three columns for fluidization through the adsorption technique balanced pressure - PSA interlinked with intake and exhaust valves, where the particulate materials adsorbents (CPT and ACP) are deposited. In this equipment are coupled devices that allow composition measurements and flow rate of gas continuously without the need to interrupt the flux when the adsorbent powder exchange is performed. Quantifications of the initial levels of CO2 (13 ± 1%) were carried out with adsorption evaluation in cycles of up to 300 minutes at room temperature, alternating the column with the adsorbent in each cycle. Comparison of the adsorption results of the FCT and ACP saturated with CO2 showed a higher efficiency of the ACP, with a substantial increase in adsorption rate during the first 120 minutes, reducing the concentration to 5.4 vol%. CO2 and, from this point, saturation occurs until the end of the cycle. The FCT adsorption rate reduces the concentration to approximately 8% vol. CO2, saturation occurring from that point until the end of the cycle. This percentage difference between the FCT and the ACP showed a reduction of the reactivity of the FCT to the CO2 in relation to the ACP for adsorption at room temperature.

Brazil is following the global trend of increased participation of aluminum in vehicles. Currently, vehicles of the heads have already been replaced in its entirety by aluminum. In the case of the blocks, due to the high investments in the lines of casting and machining to exchange this component, the replacement process is still in its infancy, as a function of the problems with the durability of injection arrays. However, the benefits such as reduced weight and improved performance of the engine, and generates less environmental impact result. On the other hand, one has to find a technological solution to increase the useful life of aluminum injection tooling. Some technological solutions have been researched in the industry, such as the use of special steels and machinability of the central false, which will cause this trend to be realized as new engines are released in the future. In this scenario the special steels for hot work are intended for use in tooling that usually suffer Contact with hot material to temperatures that can exceed 1.100ºC. To withstand such working conditions, while still maintaining high hardness and resistance to wear by friction and thermal fatigue, they have predetermined amounts of chemicals that provide the unique microstructure with fine grains, and carbides of different elements derived, which by turn, can achieve the desired thermal stability for thermal cycles of this process with as severe. This work aims to identify the cause of the failures occurred in the central dummy fixed array of HPDC aluminum injection tooling (High Pressure Die Casting), made of AISI and / or H Series Premium for hot work. Were
carried out physicochemical characterizations by metallographic tests with fractographic analysis in the vicinity of fractures in order to identify the types of cracks (transgranular or intergranular), by means of scanning electron microscopy (SEM) with energy dispersive analysis Ray Spectroscopy X (EDS) and Optical Spectroscopy (EO), and withdrawal of mechanical properties using Vickers hardness testing and traction, and analysis efforts. The results allowed to conclude that the tool presented, in addition to thermal fatigue, mechanical stress levels above the yield strength, as evidenced by the appearance of microcracks, with ductile fractures observed in the early failures regions.

Cartilage is resistant and elastic tissue which covers the surface of the bone and joint structures composed. Its function is related to the sliding the joint surfaces to each other in a smooth and frictionless way, giving support and evenly distributing the intra-articular pressure. The rheumatic or traumatic injury cartilage leads to a decrease in protection subchondral bone. This structure is innervated and sensitive
to the pressures and impacts, resulting in joint pain, functional limitation and in severe cases there is a total loss of movement. As an alternative to treatment of joint problems proposed devices as a structured in the form of hydrogel. Among the materials with potential for obtaining hydrogels can be highlight the sodium alginate, showing hydrophilic property, biocompatibility and allows cell growth. In addition, the alginate associated with the calcium chloride ion favors a reaction of gelation resulting in increased gel strength. Thus alginate hydrogel promotes proper hydration to recovery from injury and provides support and functional cartilage formation. However these materials have lower resistance observed in joint systems. Another important material in the preparation of hydrogels corresponds to the polyacrylic acid
(PAA) having properties as bioadhesiveness, ionic character and capacity to form polymeric networks which result in swelling of the gel and increase in the capacity of water absorption. In this work hydrogels were prepared by mixing aqueous solutions of sodium alginate 1% (w / v) aqueous solution of polyacrylic acid (1% v / v) at varying pH values between 4.0 ± 0.1 5 5 ± 0.1 and 7.4 ± 0.1, followed by crosslinking with an aqueous solution of calcium chloride. The films obtained from the blends of sodium alginate and PAA were characterized by SEM, XRD, DSC, TGA, FTIR, degree of swelling and mechanical tests. Results show the formation of hydrogels, and the influence of pH on the crosslinking of sodium alginate and PAA. It is believed that this hydrogel can check the mechanical properties, biocompatible films and to
enable their use for applications in tissue engineering.

One of the biggest problems in Brazil and other countries around the world refers to the lack of sanitation or the lack of clean water and collection and transport of sewage. In order to solve this problem, it is necessary to carry out major infrastructure projects of sanitation, which should be designed considering the useful life of at least thirty years. There are a large number of materials used in the manufacture of sanitation pipes (Polyvinyl Chloride (PVC), High Density Polyethulene (PEAD), steel, ductile iron, concrete, ceramics and Glass Reinforced Plastic (GRP)), either in piping system of water supply or sewage comes always aim to improve the quality of human life. Therefore, due to the high competition of various types of materials on the piping market, so it is vital the study of the piping structural life of Glass Reinforced Plastic (GRP) with minimum expectation of fifty years for sanitation, infrastructure networks (water supply and sewage), thus aiming at improvement of technical knowledge on the GRP pipes and their increased use in infrastructure projects. This work verifies the minimum expectation of fifty years of service life by applying methodologies comprising the achievements of destructive mechanical testing of long-term specimens of GRP pipes for more than ten thousand (10,000) hours, according to ASTM D 2992 06 - Procedure B and ASTM D 3681 06 Standards. These tests are commonly known as HDB (Hydrostatic Design Basis) and Strain Corrosion Design Basis. The points of failure were recorded and plotted on graph of time of failure versus circumferential elongation (log x log), which were set for the regression line, so that the circumferential elongation of failure was extrapolated to 438,000 hours, or was and extrapolated set to fifty years of expected minimum use of FRP pipes. The results showed that the methods used are appropriate to verify and predict the structural life of GRP pipes for the long term of fifty years, and demonstrated that the values of HDB and Strain Corrosion found are satisfactory and consistent when compared to others tests of HDB and Strain Corrosion performed worldwide in GRP pipes manufactured by the same production process of continuous winding (Filament winding - Flowtite Technology)

The study of sunscreen products capable of preventing epithelial neoplasms becomes extremely relevant since the ultraviolet radiation from sunlight from damaging the genetic material from other cellular changes. Several proposals for greater access to these products, such as sanitary reclassification, compulsory dispensation, coupled with re-education programs are under study by the National Health System-SUS and National Sanitary Surveillance Agency-ANVISA. Faced with the need for the development of safer and more effective sunscreens, sensory pleasing this study aims to use particles biphasic calcium phosphate (BCP) associated with titanium dioxide feedstock way possible without resorting to introduce new UV filters. The work was structured with the characterization of raw materials and 50:50 mixtures with and without heat treatment using X-ray diffraction (XRD) and Scanning Electron Microscopy rays, as well as its ability to optical absorption in the UV-Vis and phase transformation hydroxyapatite and β-TCP formation of calcium titanate. The XRD showed a profile with diffraction peaks indicative of compound BCP no impurities and titanium dioxide. The transformation of phases and formation of calcium titanate was observed since 2 hours of sintering of mixtures. From SEM analysis of the topographical observed that higher temperatures result in increased time and surface smoothness. The capacity of the optical absorption of the mixtures showed that even a simple mixture promotes satisfactory absorption profile in relation to the pure compounds. The sintered mixture for different times showed a similar profile unsintered mixture, indicating that the phase transformation and the formation of the calcium titanate does not increase the optical absorption in the UV region but shifts the curve contributing to the improvement of the appearance of undesired white film in sunscreens. We conclude that the material has optical absorption spectra suitable for the purposes of this study, which is the use of these compounds in sunscreens. The calcium phosphate particles are applied as cosmetics ingredients for a variety of products necessary protection against ultraviolet radiation, especially when seeking less sensitizing products.

The skin is the biggest organ of the body corresponding to 20% of the total body mass. Among other functions, the most important match is the first immunological barrier of the body. Without the cover skin without harmony the organism such that it may be incompatible with life. Therefore, from pre-history, the treatment of wounds, especially skin wounds, was modified in order to improve their healing process. Cutaneous lesions judged as more significant for the present work, the injuries are burns and chronic ulcers. In studies of tissue engineering hydrogels are of great interest, and a polymer that best meets the needs of a hydrogel for biomedical purposes is chitosan. In this study, chitosan hydrogels were crosslinked with adipic acid in the presence of water soluble carbodiimide to obtain films for potential application in the treatment of skin lesions. The raw material was characterized by techniques of viscometry, FTIR, potentiometric titration, DSC, TGA, XRD. The films were produced in turn characterized by OM, SEM, XRD, FTIR, DSC, TGA, and their mechanical properties were evaluated, GI and transmission of watervapor. The material investigated showed promising results as for future use as biomaterial, in view of its mechanical properties and cell viability was that were compatible with the characteristics of epithelial tissue, and thus makes it a potential for tissue engineering. In addition to other modulation results as the degree of swelling and TVA promoted by the amount of crosslinking in the material. It is expected that the results may enable the continued investigation of these materials.

Cutting fluids are used in machining processes by presenting several benefits throughout their operations. However, environmental issues have become increasingly important within the productive processes, adding to the economic and technological aspects. Taking into account the high demand of mineral emulsifiable cutting fluid, there is a need to better leverage them in order to avoid premature disposal as well as reformulation strategies for improvements in the machining process. This work was initially performed monitoring of mineral emulsifiable cutting fluid with continuous use in the process of cylindrical grinding diving employing the parameters concentration of mineral oil in emulsion, density, viscosity and pH (hydrogen potential) over 9 cycles rectification, addition analyzing the changes of chemical, physical and microbiological suffered by cutting fluid through its degradability after 6 months of use. The monitoring results showed significant variations in the values of concentration and pH. The results of degradability showed changes in pH, acid value, total solids, chemical oxygen demand (COD), conductivity and increase of microbial contamination. Subsequently, a new emulsion was used in order to achieve the rectifier set parameters when affected by the degradation in order to increase the life time through the recommendations of the manufacturer of cutting fluid with the use of triazine-based biocide and alkalizing over a period of four months. As a result of monitoring is observed that the values of concentration and pH significant variation, but the pH values remained within the manufacturer's specifications, microbiological counts remained within the parameters and the degree of corrosion decreases with the addition of biocide. Then, we propose a reformulation of cutting fluid with the addition of additives: Oily Agent (A1) Lubricant Component (A2) and Extreme Pressure (EP) (A3), aiming at improving the efficiency of the process. The results showed a better performance of the emulsion admixed with the additive Extreme Pressure (EP) (A3). Then, the emulsion was reformulated, emulsified and wrapped in the shell of the rectifier. There was monitoring the concentration, pH, degree of corrosion and microbiological count in order to adjust the properties affected during the grinding process. This redesign aims to increase the lifetime of the emulsion additive. As a result of tracking observe that the concentration values show significant variation and the pH did not undergo significant variations. The pH remained within the optimal job specifications, the microbiological count remained within the established parameters and the corrosion rate decreases with the addition of biocide. Finally, we evaluated the performance of another industrial biocide based on the 2,2-dibromo-3-nitrilopropionamide, increasing the lifetime of cutting fluid. This provides a mechanism for biocide control microbial proliferation different from the basis of triazine biocide because it does not release formaldehyde. There was monitoring the concentration, pH, degree of corrosion and microbiological count. The monitoring results showed a reduction of microbial contamination and a subsequent drop in pH, thus requiring the use of alkalizing and a tendency of increased corrosion rate of the emulsion. The results enabled the reuse of the cutting fluid by adjusting the basis of biocide triazine, because it resulted in the maintenance efficiency of the process with maintaining the operational parameters of fluid usage when compared with the commercial advantage of a cleaner production and the increased life time of the fluid. The reformulation of the fluid gave a better performance of the process and increase the life time. The results of the recoverability of cutting fluid through adjustments of biocide based on 2,2- dibromo-3-nitrilopropionamide presented maintaining operating parameters, but the corrosion rate is critical.