Crystal plasticity finite element simulations for single phase titanium alloys: effect of polycrystalline aggregate features on the mechanical response

Within the rate-independent crystal plasticity framework, a constitutive model was constructed to describe the uniaxial tension of polycrystalline titanium alloy at ambient temperature by considering crystallographic slip as the main deformation mechanism. The three-dimensional (3D) Voronoi tessellation (VT) geometric model was used to create the polycrystalline aggregates for initial microstructure. Based on the model, the effects of polycrystalline aggregate features on the macroscopic mechanical responses were discussed. Results show that the size differences of the three directions in polycrystalline aggregates will lead to the anisotropies of the stress-strain responses in the three directions, wherein the necking phenomenon appears in the long length direction. Besides, it is found that the grain morphology and orientation have significant influences on stress-strain responses as well. The proposed model for single phase titanium alloy provides important informations for the microstructure controlling and the optimization of process parameters.