Eur. Phys. J. D 50, 241-251 (2008)
https://doi.org/10.1140/epjd/e2008-00212-2

Molecular dynamics study of the micro-spallation

CEA, DAM, DIF, 91297 Arpajon, France

Corresponding author: ^a laurent.soulard@cea.fr

Received: 15 July 2008
Revised: 10 October 2008
Published online: 14 November 2008

Abstract

We present a complete molecular dynamics analysis of the micro-spallation, which corresponds to the various events following the reflexion on a free surface of a unsustained shock wave causing the melting of the material. In a first stage the various curves required for a purely thermodynamic analysis (Hugoniot, melting curve and isentropes) are calculated by the mean of both equilibrium and non equilibrium molecular dynamics. Next we define two cases. In the first one the shock pressure is above the melting pressure (SM case). In the second one the melting occurs during the release wave following the shock (RM case). These two configurations provide quite similar results if the melting kinetic of the SM case is slow enough and we observe the formation of a solid micro-spall. In the other SM cases a direct transition from a liquid to a gas is obtained. As other results we found that (i) the melting under shock is a stationary process in the front shock referential and so is supported by the Rayleigh line and (ii) the spall strength of the micro-spallation is negligible.