Modeling of Crystallographic Texture in Plastic Flow Machining

Abstract

Plastic flow machining (PFM) is proposed as a new severe plastic deformation (SPD) technique capable of producing ultrafine-grained sheet metal from bulk sample. Herein, a model is proposed for the three strain paths that the material follows during the PFM extrusion process. The proposed strain paths are justified by modeling the texture evolution in good agreement with the experiments in the three deformation zones. Two polycrystal models are used to simulate texture evolution: the viscoplastic self-consistent (VPSC) polycrystal approach and the Taylor-type lattice curvature-based grain fragmentation (GR) model. The simulations reproduce faithfully all three textures observed experimentally within the sheet. The experimental texture in the zone carrying the smallest strain is obtained with the VPSC approach, whereas in the higher strain region, the GR model reproduced the texture. The two main results of this modeling are as follows: 1) an example is presented for the successful identification of the deformation mode in a new SPD process with the help of the crystallographic texture. 2) At large strains, the VPSC model fails; it is the Taylor deformation-based GR approach which is able to reproduce the experimental texture evolution. © 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim