Fig. 1. Graphical abstract. (a) Conceptual design of Al/W energetic composites synthesized via high-speed impact. (b) High-resolution microstructural images of Al/W energetic composites. (c) Distribution characteristics of internal W particles in Al/W composites revealed by metallographic polishing. (d) W crystals (atomic spacing d = 0.229 nm) embedded within adjacent disordered crystalline matrix. (e)-(f) Atomic aggregation process and temporal evolution of potential energy by molecular dynamics simulation. A novel Al/W energetic composite, characterized by uniformly dispersed components, high reaction enthalpy (9014 J/g), rapid energy release rate (54.0 mW/mg), and a unique embedded microstructure, was successfully synthesized via high-speed impact induction. This innovative methodology not only effectively resolved persistent particle agglomeration issues in conventional fabrication but also induced significant microstructural modifications, including matrix grain refinement, formation of metastable crystalline phases, and precise heterogeneous particle embedding. Numerical simulations revealed that the distinctive embedded microstructure substantially enhances energy release efficiency by providing abundant nucleation sites for exothermic reactions, thereby improving the performance of Al/W energetic composites. Consequently, this approach offers a promising strategy for the functional design and engineering applications of other advanced energetic composites. • A high-speed impact fabrication strategy based on gas–solid two-phase flow technology was developed to synthesis powder composites with excellent dispersion and engineerability. • Al/W energetic composites with an embedded microstructure were designed, exhibiting a highly concentrated exothermic reaction with an enthalpy change of 9014 J/g. • The embedded heterogeneous tungsten particles provided additional nucleation sites for the reaction, thereby enhancing the energy release efficiency of the composite by 95.8% compared to pure aluminum. Aluminum-based energetic materials often suffer from limitations due to surface oxide layers, resulting in insufficient combustion efficiency and hindering the full utilization of their energy and application potential. To address the inherent trade-off between energy release efficiency and safety performance, microstructural engineering strategies have been developed. Specifically, utilizing the technology of gas–solid two-phase flow, an Al/W energetic composite was synthesized via a high-speed impact method. This composite exhibited concentrated energy release, high reaction enthalpy change, uniform dispersion without agglomeration, and a distinct discrete embedded microstructure. Thermogravimetric-differential scanning calorimetry analysis revealed a significant enthalpy change of 9014 J/g and a maximum heat release rate of 54.0 mW/mg during the reaction, surpassing pure aluminum powder by factors of 6.9 and 12.5, respectively. Molecular dynamics simulations were utilized to unveil the concentrated energy release mechanism of Al/W energetic composites with embedded microstructure by providing additional nucleation sites for rapid energy transfer, resulting in a 95.8% enhancement in potential energy rate compared to pure aluminum. This composite features a straightforward synthesis process scalable for mass production, offering a novel pathway for developing advanced energetic composites with analogous embedded structures and enhanced properties.
Song et al. (Fri,) studied this question.