A simplified criterion for deformation banding applied to deformation texture simulation

Abstract

Recently it has been experimentally demonstrated that deformation banding is a more important deformation mode in polycrystalline FCC metals and alloys then has been realized and by incorporating it into the original Taylor model, a Deformation Banding (DB) model which allows texture simulation to be performed was proposed. The simulated textures are closer to experiment than those from other existing models in mainly two respects. Firstly, the DB model predicts the co-existence of the three major FCC rolling texture components, namely {l_brace}123{r_brace} or S component, {l_brace}112{r_brace} or C and {l_brace}110{r_brace} or B. The existing models are deficient in that they predict either C and S or B, but not their co-existence. Secondly, textures predicted by the existing models are always too sharp compared to experiment. The DB model predicts texture peaks with larger spread and hence more realistic texture sharpness. A simplified deformation banding criterion is proposed and has been applied to texture simulation. This criterion is that deformation banding will occur when the energy for normal slip involved in DB model is less than that for RC model. The simulated FCC rolling textures from the deformation banding models (with and without the criterion) are closer to the experiment imore » mainly two respects. Firstly, the co-existence of all the three major copper type rolling texture components (S, C and B) is predicted while other models predict either C and S or just B but not the three together. The texture peaks from the two DB models are of wider spread and thus give more realistic texture sharpness when compared with the experimental results. The original DB model predicts premature decay of the C and S component at high strains. This is due to the assumption that all grains are assumed to band right upon deformation. This unrealistic assumption is eliminated by the banding criterion proposed.« less