The anisotropy of shock-induced melting of Pt observed in molecular dynamics simulations

We have performed molecular dynamics (MD) simulations to investigate the melting properties of platinum over a wide range of pressures. The embedded-atom-method (EAM) potential used here can reproduce the equation of states (EOS) of Pt well, including the 300 K isotherm and the Hugoniot P–VP–V curves. We applied shock loadings along three orientations, [100], [110] and [111], and found that responses are strongly anisotropic. Shocks along [100] lead to superheating, compared with our coexistence phase simulation results. In contrast, shocks along [110] and [111] produce supercooled liquid state. This can be understood from different Schmid factors and local dislocations generated during the shock process in the three orientations. We found strongly anisotropic plastic deformations and various metastable structures under the extremely high strain rates.