Banca de DEFESA: ARTHUR HENRIQUE IZUMI DE ABREU

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : ARTHUR HENRIQUE IZUMI DE ABREU
DATA : 28/02/2019
HORA: 13:00
LOCAL: Sala 330 - Prédio Escolar
TÍTULO:

Evaluation of the influence of heating rate, grain size of aluminum powders and magnesium alloy (AZ91) on the production of metallic foams.

PALAVRAS-CHAVES:

Metallic Foams, aluminum powder and AZ91, powder metallurgy, titanium hydride.

PÁGINAS: 75
GRANDE ÁREA: Engenharias
ÁREA: Engenharia de Materiais e Metalúrgica
RESUMO:

Engineering materials tend to be lighter and stronger as a requirement for structural applications. In this context, metallic foams are gaining more and more importance in this field of industrial applications, especially in the aeronautical area. This work aimed to contribute to the research on metallic foams and to improve the manufacturing route through powder metallurgy. The influence of the granulometry of the powders used, the green compacting rate, the concentration (mass fraction) of magnesium and the kinetic parameters (temperature versus time) in the production of aluminum foam were studied. Four aluminum powders of up to 99% purity were mixed with 1% titanium hydride and the addition of 5% magnesium alloy (AZ91) was evaluated. They were then packed in a mold designed for the study of metal foams constructed from SAE 4340 steel. They were then loaded into a muffle furnace and heated at a rate of 6 ° C, 16 ° C and 40 ° C per minute until the temperature of 710 ° C and maintained at that temperature for 8 minutes. The post sintering body was cut to analyze the internal structure of the matrix in relation to the geometry and the distribution of the pores. As a result of the processing, it was found that the foam quality is tied to a narrow distribution range of the sizes of the powders used (aluminum, AZ91 and the titanium expander-hydride agent) which allows better uniformity of compaction along the matrix, generating a high level of porosity. It was observed that the heating rate should be sufficient for nucleation and growth of the pores, but not so high to avoid coalescence. The presence of magnesium (AZ91) apparently facilitated the coalescence of the pores and increased the hardness of the material. It was also observed that the higher the compaction pressure (green densification) the greater the entrapment or confinement of the generated gases ( ) inside the matrix, which results in the formation of pores.

MEMBROS DA BANCA:
Interno - IVETE PEIXOTO PINHEIRO SILVA - CEFET-MG
Interno - LEONARDO ROBERTO DA SILVA
Externo ao Programa - MARCELLO ROSA DUMONT
Presidente - SIDNEY NICODEMOS DA SILVA