Micromechanical Finite Element Simulation of Low Cycle Fatigue Damage Occurring During Sliding Wear Test of ECAP-Processed AA7075 Alloy

The purpose of the present study was to establish a high-fidelity numerical model to analyze the effect of severe plastic deformation on the wear behavior of severe deformed Al-7075 alloy by equal channel angular pressing (ECAP). Hence, we developed a numerical model based on micromechanical principles integrating the finite element method (FEM) and the low cycle fatigue concept (LCF). In this study, we conducted wear tests using pin-on-disk technology under different normal load conditions and studied the surface/subsurface and debris of worn specimens using scanning electron microscopes (SEMs). In order to identify the related parameters of the Manson-Coffin (M-C) constitutive equation, FEM results and experimental data were utilized. Numerically, LCF relationships were proven as the most accurate mathematical description of wear during ECAP processing of Al-7075 alloy. A decrease in wear rate was also observed as the ECAP pass number increased. According to SEM micrographs of worn samples, adhesion wear and delamination are the leading wear mechanisms for annealed alloys, whereas abrasion wear and plowing bands are the leading wear mechanisms for ECAP-processed alloys.