Optimizing HMX/RDX based: balancing cost reduction and performance stability through partial RDX substitution

Polymer-bonded explosives (PBX) based on HMX offer exceptional detonation performance but are limited by high costs. This study investigates the feasibility of reducing costs by partially substituting HMX with RDX while maintaining energy output. Four HMX-based PBXs with RDX doping ratios of 0%, 8.3%, 16.6%, and 24.9% were prepared and characterized. Results indicate that RDX incorporation has minimal impact on the formulation’s microstructure. However, at 24.9% RDX content, Differential Scanning Calorimetry (DSC) revealed a 6°C decrease in decomposition peak temperature and a 15 kJ/mol drop in activation energy. Cylinder tests showed only a marginal reduction in Gurney energy (2.99 mm·μs⁻¹ vs. 2.97 mm·μs⁻¹). Validated by explosive driving tests and multi-physics simulations across various media, the velocity differences remain negligible. These findings confirm that partially replacing HMX with RDX is a viable, cost-effective strategy for PBX formulations without significantly compromising performance.