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

doi:10.12382/bgxb.2025.0439

Abstract

Abstract:

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 10nm ANP is simulated in a high-temperature and high-pressure environment (2500~3500K) containing the principal detonation products of CL-20 (CO₂, H₂O, 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 H₂O and plays a pivotal role in promoting the oxidation of aluminum oxidation and the release of energy within the range of 2500~3500K. 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.

Key words: aluminized explosive, aluminum nanoparticle, afterburning reaction, ReaxFF reactive force field, molecular dynamics

ZHONG Haoyuan, SONG Qingguan, JIANG Shengli, ZHANG Lei, PANG Siping. Molecular Dynamics Simulation of Afterburning Reactions of Aluminum Nanoparticles in the Detonation Product Atmosphere of CL-20[J]. Acta Armamentarii, 2025, 46(10): 250439-.

Figures/Tables 8

Fig.1 Schematic diagram of model construction and reaction process

Fig.2 Schematic half-section of ANP model in a CL-20 detonation atmosphere

Fig.3 Evolution of the number of molecules over time at different temperatures

Fig.4 Evolution of major chemical bonds over time at different temperatures

Table 1 Consumption ratios of CL-20 detonation products at different temperatures

温度/K	R_CO/%	R_CO₂/%	R_H₂O/%	R_N₂/%
2500	14.14	32.93	21.55	0.66
3000	14.22	38.09	25.86	0.65
3500	10.20	43.43	31.55	0.63

Fig.5 Reaction mechanisms of CO2 with Al and H2O with Al at 3500K

Fig.6 Evolution of H, HO, and H2 species over time at different temperatures

Fig.7 Snapshots of ANP during the temperature rise and constant-temperature reaction stages

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