Preparation of HMX/TATB high-energy composite particles with high safety by coaxial flow focusing microdroplet method and study of their properties

To enhance the safety of high-energy explosives while maintaining high energy output, HMX/TATB composite particles were fabricated using a coaxial flow focusing droplet method. Ethylene-vinyl acetate (EVA) and ethyl cellulose (EC) were employed as the binder system. The effects of varying TATB mass fractions on the morphology, particle size, thermal behavior, chemical structure, mechanical sensitivity, fluidity, ignition and combustion characteristics, and detonation performance of the composite particles were systematically investigated. The results revealed that with increasing TATB content, the particle morphology gradually transitioned from spherical to bowl-shaped and ring-shaped, primarily due to the decrease in droplet viscosity. XRD and FTIR analyses confirmed that the crystal structures of β-HMX and TATB remained stable without significant changes during the preparation process. As the TATB content increased, the composite materials exhibited delayed thermal decomposition and significantly improved impact safety, with the critical impact energy increasing by up to 900 %. Moreover, when the TATB mass fraction was 20 %, the composite particles exhibited optimal fluidity with a repose angle of 18.83°. Ignition tests and theoretical detonation calculations demonstrated that as the TATB content increased, the composite particles transitioned from combustion to thermal decomposition, thereby significantly enhancing thermal safety while maintaining a high detonation energy output. This study offers a theoretical foundation and technical pathway for designing high-energy materials that achieve a balance between energy density and safety performance.