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As a kind of high explosives, aluminized explosive cannot release the energy maximumly, which is a key problem. Using DTA-TG equipment, the ignition performance of three kinds of aluminized explosives (RDX, HMX, and CL-20) with different mass percentages of aluminum powder (0%, 10 wt.%, 20 wt.%, and 30 wt.%) was investigated. e results showed that the energy release of the HMX/Al composite explosive with 10 wt.%, 20 wt.%, and 30 wt.% aluminum powder was only equivalent to 80%, 65%, and 36% of pure HMX, respectively. It was similar to RDX/Al and CL-20/Al composite explosives, except the CL-20/Al mixture with 10% aluminum powder. Rather than participating in the ignition and combustion, the aluminum powder does effect the complete reaction of RDX, HMX, and CL-20 in the initial stage of ignition or in the lower temperature area of the boundary.

DSC experiments were conducted on the 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaaza-tetracyclo-[5.5.0.05,9.03,11]-dodecane (also known as HNIW or CL-20) and CL-20 containing 10 wt.% microsized aluminum (Al) powders. The kinetic parameters of CL-20 and CL-20/Al were obtained by ASTM685 and Friedman methods, respectively, indicating that Al powder decreases the activation energy of CL-20 slightly and has a catalytic effect on the thermal decomposition of CL-20. By the method of nonlinear multivariate regression, kinetic models of CL-20 and CL-20/Al were derived as fα=1−αn1+kcat⋅α, where the lgkcat of CL-20 and CL-20/Al is 1.97 and 2.12, respectively, showing that the autocatalytic ability of CL-20 had been increased by adding Al powder. From the SEM images of CL-20/Al and the XRD pattern of the decomposition residues of CL-20/Al, it can be inferred that partial combustion of Al particles happened in the microscale view and led to the release of heat.

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High sensitivity limits the broad application of CL-20 despite that it is considered as the most powerful explosive. Numerous efforts and technologies of fabricating CL-20 with small particle size have been implemented for solving this problem. In this study, CL-20 with sub-micron particle size was prepared by superfine comminution technique. The results of impact and friction sensitivities tests showed that the mechanical sensitivities of CL-20 were improved after ultra-fine treatment. DSC results showed that the decomposition of CL-20 advanced with the particle sizes decreased. The sub-micron sized CL-20 showed lower activation energy (E α) compared to that of raw CL-20, suggesting that particle size reduction is in favour of decreasing the threshold of decomposition. The reaction models of CL-20 with different particle sizes could all be categorized as n-th order reactions with autocatalysis. The function of reaction mechanism could be expressed as f(α) = (1-α) n (1 + k cat * α). On aspect of heat sensitivity, the results of deflagration point tests showed that although particle size had little influence on the deflagration point with 5 s delay time (T b) of CL-20, apparent activation energy of explosion (E b) decreased apparently with the particle sizes decreased, which could impact the thermal sensitivity significantly.