Spinodal decomposition as a possible void initialization mechanism for spallation in shock melted materials under high strain rates

We show with molecular dynamics simulations that spinodal decomposition is a probable initiation mechanism of spallation in impact-melted samples at extremely high strain rates. The formation of voids or bubbles is a secondary process following the spinodal amplification of density fluctuations. As a result, the spallation strength can be related to the inherent thermodynamic property of the liquid, i.e., the liquid-gas spinodal curve, which can be determined by independent equation-of-state studies in prior. This connection between high strain-rate spallation and spinodal decomposition may be further examined in future experiments.