Simulation of Plastic Deformation Behaviors of Ti3Al Single Crystal with Crystal Plasticity Finite Element Method

A crystal plasticity constitutive model for Ti3Al single crystal was established based on slip deformation mechanism within the frame of crystal plasticity theory, and a program was compiled to describe it by means of secondary development of ABAQUS/UMAT user subroutine. Then we applied it to simulate the mechanical behaviors of Ti3Al single crystal with different orientations during unidirectional compression deformation. The activation of slip systems and the interaction between activation and orientation has been analyzed. The simulation results show that basal slip of (0001)<11<(2)over bar>0>, prismatic slip of {10 (1) over bar0}<11<(2)over bar>0>, and pyramidal slip of {11 (2) over bar1}<11<(2)over bar>6> can be activated. However, there is dramatic difference on the ease or complexity of activation of various slip systems, which is due to the difference of critical shear stress and Schmid factor. It is difficult for basal slip and pyramidal slip to be activated because of their larger critical shear stress, which causes the activation of basal slip and pyramidal slip just with a larger Schmid factor. Pyramidal slip systems can be initiated only when compression axis is close to [0001] direction due to the maximum critical shear stress. Prismatic slip is much easier to be activated and also has the largest contribution to plastic deformation. Furthermore, the simulation results are in good agreement with the experimental results.