Banca de DEFESA: VITOR FERREIRA VIEIRA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : VITOR FERREIRA VIEIRA
DATE: 24/05/2023
TIME: 10:30
LOCAL: Microsoft Teams
TITLE:

ANALYSIS OF MECHANICAL CHARACTERISTICS OF THIN FILMS IN SIMULATION OF TRIBOLOGICAL TESTS BY THE
FINITE ELEMENT METHOD

KEY WORDS:

Finite element method, DLC, Nanoindentation

PAGES: 101
BIG AREA: Engenharias
AREA: Engenharia Mecânica
SUBÁREA: Processos de Fabricação
SUMMARY:

The diamond-like carbon (DLC) coating is a thin film that has high hardness, chemical inertia and low coefficient of friction, characteristics that can improve the performance of cutting tools and mechanical components. In order to identify these characteristics, it is of great importance to carry out mechanical tests, such as nanoindentation, which can reveal valuable information regarding the understanding and improvement of coating techniques and, when combined with the finite element method, lead to detailed results of the behavior of the specimen during the test. Taking this into consideration, the present work aimed to develop a finite element model for the nanoindentation test of a sample composed of high-speed steel coated with a thin film of DLC, in order to verify the feasibility of using the model as a substitute for the nanoindentation test. For this, a finite element model was elaborated for the test. The impact of simplifying only one indentation, the variation of the indenter tip radius, the use of a two-dimensional model for the test and the influence of friction during the test were evaluated. It was noted that the use of only one indentation to describe the partial indentation test has a great impact on the results. Changing the tip radius for the nanoindentation test does not have a significant impact on the curve of indentation force x displacement of the indenter or the hardness obtained for the material. The simplification of the model to two-dimensional has the impact of simplifying the Berkovich indenter from pyramidal to conical, also significantly impacting the test processing time. The variation in the coefficient of friction was not relevant to the results. After that, the film thickness was varied from 1.5 µm to 1.0 µm and 2.0 µm. Better mechanical characteristics of hardness, stress behavior and deformation were noted during the test for the 2.0 µm thin film. It was possible to verify the feasibility of using a mathematical model using the finite element method to simulate the nanoindentation test in order to complement or replace the performance of experimental tests, having as a limiting factor the purpose for carrying out the tests.

COMMITTEE MEMBERS:
Externo à Instituição - JÁNES LANDRE JÚNIOR - UFMG
Externo à Instituição - PAULO SÉRGIO MARTINS - UNA
Interno - SANDRO CARDOSO SANTOS
Presidente - YUKIO SHIGAKI