Differential regulation of Al/CuO thermite combustion via alloy fuels and electrostatic spray atomization

This study addresses the issues of the limited contact interface between the fuel and the oxidizer. A strategy for simultaneously optimizing the formulation design and the preparation process was proposed. Three types of fuels - pure aluminum, aluminum-magnesium alloy, and aluminum-silicon alloy - were selected, and polyvinylidene fluoride (PVDF) was used as the binder. Six groups of thermal reaction samples were prepared by two methods: physical mixing (PM) and electrostatic spray atomization (ES). The microstructure, combustion characteristics, thermal behavior, and product composition of the samples were systematically studied using scanning electron microscopy, X-ray diffraction, high-speed photography, infrared thermal imaging, and synchronous thermal analysis. The results showed that the alloy fuels affected the later stage of the reaction by altering the melting behavior and surface oxide layer characteristics, while electrostatic spray atomization played a key role in the early stage, functioning by shortening the mass transfer distance and enhancing the “pre-ignition” effect of polyvinylidene fluoride. The coupling of fuel formulation and preparation process enables differential modulation of the combustion performance of Al/CuO thermites. This study provides an effective strategy for developing high-performance aluminum-based thermite materials.