Análise do comportamento de fadiga da liga de alumínio 7075 solubilizado e envelhecido

Imagem de Miniatura
Tipo
Dissertação
Data
2016-08-09
Autores
Paz Gonzalez, José Fernando
Orientador
Couto, Antonio Augusto
Título da Revista
ISSN da Revista
Título de Volume
Membros da banca
Vatavuk, Jan
Lima, Nelson Batista de
Programa
Engenharia de Materiais
Resumo
In recent decades the aluminum had a great evolution since the beginning of his story that came to have a greater value than gold, to the present day that it is used in our days from a tin of soda to key parts of an airplane. With the growing need in various industrial segments, especially the aeronautical and automobile industries, wherein the weight reduction is a concern, the study of this material becomes important. This work has as objective the study of aluminum alloy 7075 solubilized and artificially aging were studied in which the main mechanical behavior of this material. It was performed the hardness, tensile tests and the focus, fatigue test, in which was observed a hardness of 230 HV and mean tensile strength of 676 MPa and yield strength of 615 MPa. The study of fatigue behavior was done in a rotating bending testing machine at ambient temperature to developing the Wöhler curve also known as S-N curve (tension x No. of cycles), who showed the characteristic of non-ferrous materials An specimen reached number of cycle greater than 8,4x106 with the stress of 135 MPa. The fracture surfaces showed the typical characteristics of crack propagation and ductile overload fracture and showed differences in the type of crack propagation in low cycle when compared with medium and high cycle, besides that was showed ratchet marks and fatigue stretch when observed with SEM. It was observed the presence of dimples associated with the precipitates.
Descrição
Palavras-chave
solubilização , metalografia , micrografia , materiais metálicos , curva de Wohler , tratamento térmico , flexo rotativa
Citação
PAZ GONZALEZ, José Fernando. Análise do comportamento de fadiga da liga de alumínio 7075 solubilizado e envelhecido. 2016. 85 f. Dissertação (Engenharia de Materiais) - Universidade Presbiteriana Mackenzie, São Paulo .