Molecular Dynamics Simulation of Afterburning Reactions of Aluminum Nanoparticles in the Detonation Product Atmosphere of CL-20

The afterburning reaction mechanisms of aluminum nanoparticles (ANPs) in the detonation product atmosphere of aluminized explosives are studied using the ReaxFF-lg reactive force field alongside reactive molecular dynamics (MD) simulations. The combustion process of a 10 nm ANP is simulated in a high-temperature and high-pressure environment (2 500 ~ 3 500 K) containing the principal detonation products of CL -20 (CO₂, H₂ O, CO, and N₂), revealing the reaction mechanism of ANP in a multi- component oxidizing atmosphere at the atomic scale. Results indicate that the formation of H—Al and H—C bonds decreases as the temperature rises, which indicates that the elevated temperatures are not conducive to the creation of hydrogen-related stable structures. Additionally, the proportion of CO₂ among detonation products emerges as the primary determinant of detonation temperature. CO₂ demonstrates greater reactivity than H₂ O and plays a pivotal role in promoting the oxidation of aluminum oxidation and the release of energy within the range of 2 500 ~ 3 500 K. Thus, increasing the content of CO₂ in detonation products can effectively regulate detonation temperature and boost the combustion efficiency of ANPs, enabling more complete energy release. These findings offer a theoretical foundation for designing high-performance aluminized explosive formulations.