Plasticity Mechanism Associated with Nano-Void Growth under Impact Loading along 〈111〉 Direction in Copper

Evolution of Nano-void (diameter d1.3 nm) in single crystal copper and associated plasticity deformation around the nano-void under impact loading are investigated by means of molecular dynamics (MD) simulation. The results of simulation reveal that in the tensile process there are three of all four {111} family planes to be activated to glide, dislocations are nucleated in the region near the void surface and then move outside on three {111} family planes as the void grows. The velocity of dislocation along 〈112〉 directions with the maximum resolve shear stress can exceed transverse sound velocity. The calculated dislocation damping constant is appropriately consistent with the experiment results. Due to the approximately symmetrical plastic deformation around the void, the shape of the void during growth process is almost spherical. The growth rate of the void radius is observed to be constant under constant shock strength, and the amplitude increases as well as the shock strength increases.