Internal Explosion Performance of RDX@Nano-B Composite Explosives

Boron powder is an additive for metalized explosives with great application potential. To improve the energy release ability of boron powder, the composites of RDX and nano-boron (RDX@Nano-B) were prepared by the spray-drying process, and the metalized explosives based on it were designed (named PBX-B1). The detonation heat and explosion pressure of boron-containing explosives PBX-B1 under vacuum and air conditions were measured and analyzed by an internal explosion test. On the other hand, the equilibrium pressure and energy release of the PBX-B1 explosive system after detonation were analyzed and compared with that of an explosive formulation of the same composition (named PBX-B2). Results showed that the detonation heat of PBX-B1 was 7456 J/g in a vacuum environment, which was 34.8% higher than that of RDX (5530 J/g). However, in the air environment, the detonation heat of PBX-B1 increased by 19.2% compared with that in the vacuum environment, and the explosive gas products mainly included N-2, NOx, CO, H2O, CH4, HCN, and CO2. The peak pressure and equilibrium pressures of PBX-B1 were 11.2 and 0.42 MPa, which were increased by 155% and 75% compared with the vacuum environment, respectively. It is worth noting that, compared with that of PBX-B2, the released energy in the aerobic combustion stage and equilibrium pressure of PBX-B1 were increased by 49.8% and 10.5%. This study demonstrated the strategy of improving the energy release of boron-containing metalized explosives through the design of an explosive microstructure, which provides important clues for the design of higher-energy metalized explosives.