High-velocity shock compression of SiC via molecular dynamics simulation

Abstract

Molecular dynamics (MD) simulation on high-velocity shock compression of cubic SiC was performed using a Tersoff potential. With particle velocities in a wide range from 0.1km/s to 20km/s, the propagations of shock waves were described in detail. The evolution processes from elastic wave to phase transition wave were revealed. It was found that the shock compression of cubic SiC shows four distinct regimes. With particle velocities below 2km/s or above 16km/s, only a single elastic shock wave or single phase transition shock wave generates. With particle velocities in the narrow range from 2km/s to 3km/s, local plastic deformation is shown in SiC materials. When particle velocities are between 3km/s and 16km/s, a well-defined two-wave structure generates, consisting of an elastic wave followed by a phase transition wave. The phenomenon of splitting shock waves is similar with the separate silicon and diamond systems. The results showed that the critical pressure for the generation of phase transition wave is 140GPa. The analysis of the simulation results showed that the theory of stress waves in macroscopic systems is suitable for microscopic systems.