Chemical reactions and energy output of aluminized RDX under shock wave

Aluminized energetic materials have been widely used in military and aerospace applications. With its high combustion enthalpy, aluminum can significantly increase the overall energy release when reacts exothermically with oxygen or oxidizers. But the performance remains undesired. There have been various studies on how to improve the performance of aluminized energetic materials. Using aluminum nanoparticles, aluminum particles coated with fluoropolymers, or mixing aluminum with other reactive metals have been proposed to improve reaction kinetics, increasing energy release efficiency and reducing ignition delays. The main challenge is the alumina surface layer covering an aluminum particle usually block the rather active aluminum from accessing oxygen or oxidizers. In this study, we propose an approach in an effort to face this challenge. We conducted a series of large scale Molecular Dynamics simulations using a reactive force field on aluminized RDX to confirm the feasibility of this concept. The simulation results bring insights into the decomposition of RDX, aluminum nanoparticles reaction with RDX fragments, and energy release dynamics of these composite explosives. The influence of particle surface with or without passivation on detonation properties is examined. Ignition delaying and aluminum oxidation efficiency are analyzed under various shock conditions.