Atomistic simulation of void growth by emitting dislocation pair during deformation

摘要

The growth of voids has an important influence on the crack and fracture of metal materials. A new atomistic method, i.e., the phase field crystal, is used to simulate the void evolution and dislocation emission of the lattice deformation process. During the deformation process, the void changes its shape as the applied strain increases. Influenced by the direction of the strain application and the orientation of the lattice atoms, the void is transformed from the original circular shape to a square shape. As the strain increases, a pair of dislocation is generated on left and right sides of the void, and pushes out on the two sides. Then, the dislocation pair is emitted from the void, and departs from it, and does the climbing movement. Finally, the dislocation pair is broken down into two independent dislocations. Using the model of the void launching dislocation, the interaction among dislocations and void in the deformation process is analyzed, and the influence of the void emitting dislocation in the void growth in the deformation process is revealed.