A theoretical investigation of the contribution of texture and dislocation sheets on strain path change effects in BCC metals

Abstract

Softening/hardening effects are often observed in BCC polycrystals during changing strain paths. They can lead to premature failure of the material. Both the anisotropy due to microstructural features as well as due to the development of preferred crystallographic orientations are considered to be responsible for these effects. This paper addresses a methodology to incorporate cells and cell blocks at the grain scale in a full-constraints Taylor model. This allows the coupling of the full anisotropy due to basic slip processes, crystallographic texture and microstructure. It is demonstrated that the model is capable of simulating the complex softening/hardening effects during changing strain paths. It is shown that the cross effect and the Bauschinger effect are mainly caused by microstructural features and not by textural effects.