Eventos Anais de eventos
MECSOL 2022
8th International Symposium on Solid Mechanics
FATIGUE LIFE OF ALUMINUM ALLOY 7075-T6511 CONSIDERING THE INFLUENCE OF INDENTATION DEFECT AND MEAN STRESS
Submission Author:
Natalia Gonçalves Torres , DF
Co-Authors:
Natalia Gonçalves Torres, Edgar Mamiya, Vinícius Rodrigues
Presenter: Natalia Gonçalves Torres
doi://10.26678/ABCM.MECSOL2022.MSL22-0077
Abstract
This work investigates the fatigue life of aluminum alloy 7075-T6511 in the presence of small surface defects and considering the effect of the mean stress. Artificial defects with 650 micrometers diameter and 40 micrometers depth were produced with a Brinell hardness test machine. Fully-reversed and positive load ratio (R = 0.1) uniaxial fatigue tests were performed. The aluminum alloy showed significant reductions in the presence of defects. For instance, when subjected to a stress amplitude of 240 MPa (less than half the yield stress), the observed life was 30 times shorter than the life of the smooth specimen. When the specimens were subjected to mean stresses, the same life reduction pattern was observed under the presence of indentation defects, as a function of the fatigue parameter SWT. Under high stress amplitudes, fatigues cracks were not nucleated in the indentation region, which is consistent with the fact that life reductions were not observed. The microstructure of the material reveals the presence of precipitates, which influenced the fatigue mechanism, as observed by the analysis of the fracture surface of the specimens.
Keywords
small defects, Fatigue Life, aluminum alloy 7075-T6511, mean stress.
