Effects of octogen on the crystallization and solidification behaviors of DNAN through microcalorimetry

To improve the damage performance of melt-cast explosives, one effective approach is to increase the proportion of solid-phase high-energy components. However, elevating the solid-phase content May alter the crystallization behavior of the 2,4-dinitroanisole (DNAN) melt or suspension, which can impact defect formation and overall quality and ultimately affecting the safety and detonation performance of the cast explosives. This study focuses on DNAN casting process with the addition of octogen (HMX) solid form, particularly examining its crystallization thermodynamics and kinetics. The effects of the content and particle size of the solid-phase additive HMX on the crystallization and solidification behaviors of DNAN are investigated using microcalorimetry, and the thermodynamic and kinetic parameters of DNAN crystallization are determined. The results indicate that incorporating HMX to DNAN increases the degree of undercooling; however, excessive HMX content damages the forming quality. Optimal forming quality and solidification rate are both achieved at a 43% content of HMX. Additionally, coarse HMX particles may impede the nucleation and crystallization of liquid-phase DNAN, making it difficult to meet the undercooling requirements.