Interfacial intermetallic reaction for oxide layer fragmentation: A coating strategy towards aluminum-based energetic materials

Metallic fuels, especially aluminum, are widely used in energetic materials for their high energy density. However, their dense surface oxide layer raises ignition thresholds and limits combustion efficiency. To address this, this study coated micron aluminum particles with transition metals (Ni, Cu, Zn) via optimized electroless plating, forming core-shell Al@M particles for Al/MoO 3 . The coated particles were characterized by SEM, EDS, XRD, and ICP-MS. Thermal analysis showed that the coatings, particularly Cu, significantly promoted exothermic reactions, lowering the main reaction peak and intensifying combustion. Ignition tests revealed shorter ignition delays for coated samples. High-speed photography confirmed larger flame areas and more violent combustion. The enhancement is attributed to the intermetallic reactions between Al and the coating metals, which generate an alloy shell with a high coefficient of thermal expansion. This disrupts the confinement of the native Al 2 O 3 layer and facilitates rapid reaction propagation. This work provides a practical coating strategy for significantly improving the reactivity and ignition performance of aluminum-based energetic materials.