Molecular dynamics study of the micro-spallation of single crystal tin

The micro-spallation of single crystal tin is studied using the molecular dynamics method. Firstly, the Hugoniot curves of tin are obtained and compared with experimental data. Secondly, the dynamical evolutionary processes of micro-spallation are investigated under various impact velocities via non-equilibrium molecular dynamics. The simulated results reasonably represent the ejection phenomena that damage, and the liquid fragments that accompany, the reflection of a strong shock wave at the free surface of the target. Our atomic-scale analysis demonstrates that the micro-mechanism of micro-spallation is attributed to melting and cavitation, i.e., nucleation, growth and coalescence of voids. Also, the primary difference between classical spallation and micro-spallation lies in the amount of voids and the distribution of void nucleation sites. The void volume distribution is quantitatively described by a power function. The relation between the formation of voids and thermal dissipation is also qualitatively discussed.