Investigation of shock front in nanocrystalline CuTa alloy via molecular dynamics method

CuTa alloy is a typical alloy with high melting point, corrosion resistance and excellent ductility, which is expected to be used as a warhead material for weaponry. In present study, molecular dynamics (MD) method is used to reveal the thermal and mechanical responses of copper-tantalum alloys under high velocity impact from the atomic scale. The model of the nanocrystalline polycrystalline CuTa alloy was established by the two different methods. The shock wave propagation process at the particle velocity of 1.3 Km/s was simulated by the “momentum mirror” method, and the polycrystalline copper-tantalum alloy during the impact was analyzed. The change of grain boundaries in the alloy and the generation and annihilation process of dislocations. The MD simulation results show that the propagation of shock waves in the copper-tantalum alloy can be divided into three stages, namely elastic deformation, dislocation emission and double-wave structure transmission. Additionally, the vacancies generated at the same time will cause local stress concentration and temperature rise. These transformations can easily be classified in MD simulation details.