Improved ignition and combustion performance of Al-Zn-Mg ternary alloys by incorporating Mg into Al-Zn alloys

Al-Zn alloys exhibited lower reaction temperature and micro-explosion phenomenon when compared to Al which benefited from the low melting point and boiling point of Zn. To further improve the energetic performance of Al-Zn alloys, Mg with low reaction temperature was originally incorporated into Al-Zn alloys via centrifugal atomization. The addition of Mg results in the production of Mg₃₂(Al,Zn)₄₉ with the low melting point and stepwise oxidation, which can effectively improve the reactivity and combustion. The results show that the prepared Al-Zn-Mg alloys display uniform particle size distribution, regular morphology, and excellent sphericity, which are composed of α-Al and Mg₃₂(Al,Zn)₄₉ compounds. The initiation oxidation temperature of AlZn10Mg5 and AlZn10Mg10 alloy powders is lower than that of AlZn10 alloy powders, and the oxidation efficiency is higher than that of AlZn10 alloys, which may be attributed to the oxidation of Mg₃₂(Al,Zn)₄₉. Adding Mg to the AlZn10 alloy significantly increases the peak pressure and pressurization rate during combustion. In the meanwhile, Al-Zn-Mg alloys burn faster, more intensely, and more completely when compared to AlZn10 alloys. The combustion of the spherical AlZn10Mg10 alloy powders is the most intense visually. It can be ascribed that during the combustion, a large amount of melt and gas breaks through the oxide layer, increasing the contact intimacy between oxygen and the alloy, which can significantly shorten the combustion time. In summary, the spherical AlZn10Mg5 and AlZn10Mg10 alloy powders prepared in this study show promising applications in fuels with high reactivity and better combustion performance.