Study on the Detonation Reaction-zone and Energy Release Characteristics of a Cast HMX-based PBX

This article gives a comprehensive study of the detonation reaction-zone (DRZ) and energy release characteristics of a cast HMX-based polymer-bonded explosive, PBX-91C, which has been demonstrated in our previous study to be an insensitive explosive. The DRZ of PBX-91C was studied by the impedance window method; the detonation reaction time, DRZ length, and detonation pressure were obtained. The cylinder test was employed to evaluate the acceleration ability of PBX-91C, the Gurney velocity and the parameters of the Jones-Wilkins-Lee (JWL) equation of state (EOS) for PBX-91C. The shock overpressure test was carried out to evaluate the energy release characteristics of PBX-91C in free-field; TNT was also tested for comparison. On the basis of the parameters of the JWL EOS determined by the cylinder test, three-dimensional numerical simulations of the shock overpressure tests were conducted. The results showed that PBX-91C is substantially more powerful than TNT; moreover, the energy release of PBX-91C is more rapid. All of these results suggest that the detonation performance of PBX-91C is close to that of RDX. PBX-91C can be a good candidate for main charges as it has both high energy and low sensitivity.