Numerical study of the effect of prior deformation history on texture evolution during equal channel angular pressing

Abstract

It is experimentally well known that mechanical properties of the material depend on crystallographic texture distribution which varies depending on deformation history. When the material deforms at several stages, it is not easy to follow up the effect of prior deformation on the final texture of the material. In the present study, the effect of deformation history on texture evolution during equal channel angular pressing (ECAP) of FCC polycrystalline metal like AA1050 is investigated by the finite element method and polycrystal plasticity model based on full constraints Taylor model. The texture evolution during the multi-pass ECAP is simulated with the initial textures determined by three virtual specimens prepared by the fully annealed, extruded, and flat-rolled materials. By comparing the pole figures and orientation distribution functions, the effect of prior deformation histories on the texture evolution is numerically studied according to the routes A and C up to four passes across the thickness of the specimen. For the extruded specimen, it is not enough to wipe out the trace of the initial textures originated from the extrusion even after four passes. For the rolled specimen, strong development of the rotated simple shear texture readily occurred with the rotation about the transverse direction of the ECAP die. This study indicates that it is necessary to control the initial texture properly for achieving a desired mechanical property.