Nanosized Al@Cu Thermite Promoting the Combustion of Boron Powder

Boron (B) has a surface oxide layer that hinders its ignition and combustion. A nanosized Al@Cu thermite was produced via a substitution reaction between Al and copper fluoride hydrochloride. This process alters the conventional Al and CuO mixture structure, with Cu etching onto Al, tightening contact between the materials, and enhancing the thermite reaction. The etching thins the oxide layer on the Al surface, facilitating active Al release. B–Al@Cu increases the exothermic heat by 460 J/g compared to pristine B and 310 J/g compared to the doped Al/CuO. The structural defect of the Al@Cu thermite allows molten Al to penetrate the Al2O3 layer during heating, triggering a strong oxidation reaction with CuO and oxygen, releasing significant heat, and diffusing the B core, which inhibits the agglomeration of B powder and enhances its oxidation efficiency. This study provides significant theoretical support and practical application potential for the design of solid propellants with B powder.