Study on the combustion performance of highly active spherical AlBi alloy particles

By exploiting the immiscible nature of the aluminum–bismuth (Al Bi) binary system, spherical AlBi10 alloy particles with a unique particle-embedded network structure were successfully synthesized using a high-speed disc-shaped centrifugal atomization method. In this structure, nanoscale Bi particles are embedded within a micrometer-scale Al matrix, forming a continuous network that subdivides the Al grains into nanocrystalline domains along grain boundaries. The embedded Bi particles, undergo micro-explosions during combustion, promoting the dispersion and rapid reaction of the Al particles. In terms of thermal behavior, the oxidation exothermic peak of the AlBi10 alloy occurs at 1000.7 °C, which is 16 °C lower than that of pure Al. The oxidation weight gain reaches 64.03 wt%, representing 7.02 times that of pure Al. Combustion performance tests revealed that the AlBi10 alloy–KP–PF sample exhibits excellent reactivity. Under ambient air, complete combustion is achieved within 3.0 s, with an average burning rate of 2.93 mm/s. Under confined conditions, the peak pressure reaches 7.52 MPa, and the pressure rise rates increases to 67.02 MPa/s. These results demonstrate that the AlBi10 alloy particles, owing to their distinctive structure, exhibit significantly enhanced reactivity and combustion efficiency compared to micrometer-sized Al particles. Therefore, AlBi10 alloy particles show great promise for applications in energetic materials.