Prediction of Crystallographic Texture Evolution and Anisotropic Stress- Strain Curves During Large Plastic Strains in High Purity alpha-Titanium Using a Taylor-Type Crystal Plasticity Model (Preprint)

摘要

A new Taylor-type polycrystalline model has been developed to simulate the evolution of crystallographic texture and the anisotropic stress- strain response during large deformation of high purity alpha-titanium at room temperature. Crystallographic slip, deformation twinning, and slip inside the twinned regions were all considered as contributing mechanisms for the plastic strain in the model. This was accomplished by treating the dominant twin systems in a given crystal as independent grains once the total twin volume fraction in that crystal reached a predetermined saturation value. The newly formed grains were allowed to independently undergo further slip and the concomitant lattice rotation, but further twinning was prohibited. New descriptions have been proposed for slip and twin hardening and the complex coupling between them. Good predictions were obtained for the overall anisotropic stress-strain response and the texture evolution in three different monotonic deformation paths on annealed, initially textured samples of high purity alpha-titanium.