Deflagration of HMX-Based Explosives at High Temperatures and Pressures

摘要

We measure the deflagration behavior of energetic materials at extreme conditions(up to 520 K and 1 GPa)in the LLNL High Pressure Strand Burner,thereby obtaining reaction rate data for prediction of violence of thermal explosions.The apparatus provides both temporal pressure history and flame time-of-arrival information during deflagration,allowing direct calculation of deflagration rate as a function of pressure.Samples may be heated before testing.Here we report the deflagration behavior of several HMX-based explosives at pressures of 10-600 MPa and temperatures of 300 - 460 K.We find that formulation details are very important to overall deflagration behavior.Formulations with high binder content(>=15wt%)deflagrate smoothly over the entire pressure range regardless of particle size,with a larger particle size distribution leading to a slower reaction.The deflagration follows a power law function with the pressure exponent being unity.Formulations with lower binder content(<=10 wt% or less)show physical deconsolidation at pressures over 100-200 MPA,with transition to a rapid erratic deflagration 10-100 times faster.High temperatures have a relatively minor effect on the deflagration rate until the HMX beta->delta phase transition occurs,after which the deflagration rate increases by more than a factor of 10.