A dislocation climb/glide coupled crystal plasticity constitutive model and its finite element implementation

The glide and climb of dislocations are two important plastic deformation mechanisms of the metallic crystals at elevated temperatures. In this work, a new dislocation density-based constitutive model for single crystal plasticity with explicit consideration of both dislocation glide and climb is presented. Three contributions of dislocation climb to the plastic deformation are involved: the kinematics, the climb-enhanced dislocation mobility and the climb-induced dislocation annihilation. A fully implicit time-integration scheme for this model is given and implemented by a user material subroutine in software ABAQUS. Then, the compression tests of < 110 > single crystalline aluminum at high temperature and low strain rate are simulated, showing good agreements with the experimental results. Moreover, this model is used to predict the creep deformation of single crystalline aluminum at different temperatures and applied stress levels. The results show that the present model can capture the power law creep behavior of single crystalline aluminum and the predicted creep exponent falls within the range suggested by earlier research.