Architecting nano‐Al/ HMX / CuO energetic micro‐units unlocks superior interface and highly efficient combustion

Abstract The combustion performance and interfacial‐mechanical properties of the Al/HMX composite are pivotal to its application in propellant and explosive formulations. Although nano‐aluminum (n‐Al) possesses high reactivity, issues such as particle agglomeration and surface oxidation limit its combustion efficiency and mechanical properties, hindering its direct application. Spherical Al/HMX/CuO composite energetic micro‐units were designed using multiscale simulations combining molecular dynamics and computational fluid dynamics. Using fluororubber F ₂₆₀₃ as the binder, the micro‐units were precisely and controllably fabricated employing coaxial microfluidic technology. Characterization indicates that the n‐Al particles are pre‐dispersed within the micro‐units, suppressing their agglomeration. The addition of F ₂₆₀₃ as an interfacial modifier enhances hydrophobicity and delays n‐Al oxidation. The spherical morphology improves dispersion and flame propagation, while the encapsulation structure promotes efficient mass and heat transfer between n‐Al and HMX, significantly enhancing combustion. In the optimized formulation with an Al/HMX mass ratio of 1:2 and 2% CuO content, the micro‐unit exhibited a 100% increase in combustion rate, a stable heating rate of 1.04 × 10 ⁴ K s ^–1 , and a 5.5% rise in combustion temperature, outperforming physically mixed samples. By revealing the combustion mechanism and structure–performance relationship of energetic micro‐units, this study demonstrates precision fabrication advantages of microfluidics to support designing high‐performance energetic composites. image