3D FEM simulation of Al-Zn-Mg-Cu alloy during multi-pass ECAP with varying processing routes

Abstract

Equal channel angular pressing (ECAP) is one of the efficient metal fabricating processes to produce very fine grain structure in materials. In the present investigation, 3D finite element method has been adopted to understand the deformation response for Al-Zn-Mg-Cu alloy with three different ECAP processing routes, namely, A, BC, and C. The simulation results revealed enormous improvement in effective plastic strain with ECAP passes for all routes; however, route BC has the edge over the other routes. In the current investigation, homogenous deformation is mainly observed across the main deformation zone (MDZ). Even after three passes, BC is found to be consistent in offering higher and relatively uniform plastic strain along with the sample thickness compared to the other routes of the same deformation level. Microstructure analysis revealed a considerable amount of grain refinement (from 74 ± 5 μm to 570 ± 7 nm) after the third ECAP pass following BC route. Also, the microstructure is featured with a high fraction of deformation bands and a high density of dislocations. The hardness, yield strength, and ultimate strength have increased to 94 %, 126 %, 53 %, respectively, compared to the initial annealed condition. The enrichment of mechanical properties can be substantiated by a significant amount of grain refinement and dislocation strengthening.