Multiscale Characterization of a Polycrystalline Aggregate Subjected to Severe Plastic Deformation with the Finite Element Method

Abstract

The heterogeneous deformation of a polycrystalline aggregate under severe plastic deformation was reproduced with finite element analysis by using single-crystal plasticity to characterize the evolution process of the heterogeneity. Finite element analyses of a periodic polycrystalline aggregate were carried out to simulate the deformation process corresponding to the multi-pass equal-channel angular extrusion process, which reached over 250% of the macroscopic logarithmic accumulated plastic strain. The numerical results were analyzed from multi-scale perspectives: the macroscopic response, evolution of the crystallographic orientation, and deformation state of the microstructure. This study addressed the importance of finite element discretization to reproduce the heterogeneous deformation of a polycrystalline aggregate, including that of the inside grains, which is a key element for investigating the underlying fine-graining mechanism.