Shock-induced chemical decomposition and detonation in RDX single crystals: Role of crystal orientation

Shock compression studies on high explosive (HE) single crystals provide insight into the intrinsic HE response, avoiding the complexities inherent to the response of composite HE formulations. To examine the effect of crystal orientation on chemical energy release and detonation characteristics in a widely used conventional HE, wave profiles were measured in RDX single crystals shock compressed to 63 GPa. At 15 GPa, RDX shocked along the [100] and [111] orientations showed wave profile features consistent with decomposition onset. Shock amplitude increase was higher for [100] RDX than for [111] RDX, suggesting that energy release was faster for [100] RDX under shock compression. At 51 GPa and above, the classic Chapman–Jouget (C–J) detonation response was observed for both orientations. Measured Hugoniot states and sound speeds for the RDX detonation products showed that the overdriven detonation response for RDX does not depend on crystal orientation. The experimentally determined C–J pressure of RDX single crystals was 35 GPa, providing support for previous calculations. Our results show that the post-detonation response of RDX is governed primarily by the structure of the RDX molecules and not by the crystal orientation.