A deformation-based model for recrystallization of anisotropic materials

In materials with high plastic anisotropy some orientations deform much more than others, leading to a large variation in strain and strain energy. It has been observed in several mineral systems that those orientations which are most deformed (''soft'') dominate the recrystallization texture. A model is proposed which relies on a self-consistent viscoplastic theory to predict the deformation of individual grains. From this model the strain energy is determined, assuming a linear hardening law. Highly strained grains are likely to recrystallize by nucleation or to disappear through invasion by neighbors. The recrystallization texture is due to a balance between nucleation (defined by two parameters, a probability parameter A and a threshold parameter B) and boundary mobility (described by a parameter C). The texture evolution during dynamic and static recrystallization for halite, quartz and ice has been simulated and results agree surprisingly well with textures observed in experimentally and naturally deformed, recrystallized materials which were difficult to explain before. The model is easily incorporated in polycrystal plasticity codes. (C) 1997 Acta Metallurgica Inc.