Molecular dynamics simulation of healing of an ellipsoid crack in copper under compressive stress

摘要

The molecular dynamics method is used to simulate healing of an ellipsoid crack inside copper under compressive stress with embedded atom method (EAM) potential. The result shows that dislocations are emitted firstly from the ellipsoid crack and move along the (11-bar 1) and (1-bar 11) planes under a constant compressive stress of 0.34 GPa. The ellipsoid crack becomes smaller and smaller until it is healed through dislocation emission, motion, and annihilation on the surfaces. After crack healing, there are a residual dislocation net and some vacancy sites. It seems that the cavity inside the ellipsoid crack is transferred to the surfaces through dislocation emission, motion, and annihilation. At the same time, the crystal undergoes large plastic deformation and the surface become rough because of dislocation annihilation.