Study of the dislocation dynamics in the plastic deformation

Using a three-dimensional model,the discrete dislocation dynamics simulation is performed at different stresses and temperatures,and the evolution of the dislocation density and the average dislocation velocity with the deformation is also discussed.The model takes into account the elastic interaction between dislocations and the slipping process against the lattice resistance,and a simplified modification of the dislocation multiplication and annihilation mechanism is adopted.The results show that both the dislocation density and velocity are in fluctuant state under the joint action of multiplication and annihilation.On the whole,the dislocation velocity increases with the increasing external stress and temperature,while the dislocation density increases with the increasing stress and decreasing temperature.