A disclination-based model for grain subdivision and its impact on the macroscopic mechanical behaviour of f.c.c. polycrystals

Abstract

An integrated substructure and texture evolution model is used to study grain subdivision and anisotropic work-hardening at f.c.c. materials under cold plane strain deformation. The substructure development is modelled with the help of coupled evolution equations for dislocation and disclination densities, separately for the twelve f.c.c. slip systems and six cell wall and fragment boundary families. The texture development is modelled with the help of a full constraints Taylor code. The couplings between the two consist in the slip rates calculated by the Taylor algorithm and driving the evolution equations, and in the critical resolved shear stresses calculated from the defect densities and entering into the Taylor code. The model is used to predict the subdivision patterns depending on the grain orientation as well as the substructure contribution to the anisotropy in the macroscopic mechanical response.