Spherical Al-Zr alloy powders prepared by centrifugal atomization for tunable energetic behavior

To improve the energetic behavior of Al, heterogeneous Al-Zr alloy powders were prepared by high-speed centrifugal atomization in this paper, the phase composition of which is Al and Al₃Zr. The thermal analysis results show that the main oxidation process of Al-Zr occurs at 800 °C–1200 °C. The oxidation peak temperature of the alloy is 25 °C lower than that of Al, accompanied with a higher weight gain and faster oxidation rate. Besides, the activation energy (E_k) is significantly reduced by 74 kJ/mol. Compared with Al/CuO, the ignition delay of Al-Zr/CuO is shortened by 0.6 ms, and the reaction temperature is advanced by 29 °C. This is due to the earlier concentrated heat release of Al₃Zr and the grain refinement of Al-Zr that aggravates the shell fracture and result in more intense oxidation of the alloy powders. Therefore, Al-Zr alloy powders possess a significantly enhanced combustion performance than Al.