Comprehensive atomic insight into the whole process of thermolysis of HMX/CL-20 mixed explosives based on a brand-new layered model of mixed explosives

Based on a brand-new and excellent layered model of mixed explosives, the thermolysis process of HMX/CL-20 mixed explosives at different temperatures was studied by reactive molecular dynamics. The thermolysis mechanism was revealed on the atomic scale, and some gratifying new discoveries were obtained. Among them, the activation energy of the mixture in two stages was lower than that of the pure HMX system in different degrees, and CL-20 would promote the thermolysis of HMX. The analysis of the initial reaction path showed that a large amount of NO2 brought by CL-20 and OH generated by HNO2 decomposition would be the important factors of this phenomenon. The direct reaction between HMX and CL-20 also changed with the change of temperature. Furthermore, the addition of CL-20 would increase the number of final products such as H2O, N2, H2. The analysis of bond number brought a new conclusion. A large number of C atoms in the mixture were in clusters, and the larger clusters would not decompose even at the high temperature of 3500 K. The “lower” external temperature cannot drove the clusters composed of so many C atoms to change. To put it briefly, CL-20 would speed up HMX’s thermolysis and alter the system’s overall response mechanism.