Thermal Analysis and Pyrolytic Behavior of Bimetal and Double Oxidant Thermite Al/Mg/MoO3/CuO

Abstract

AbstractIn order to study the effect of fuel Mg and metal oxide CuO on the reaction of thermite, different proportions of Al‐Mg alloys and MoO3‐CuO metal oxides were prepared by mechanical ball milling, and then the samples of Al1‐xMgx/(MoO3)1‐xCuOx composite thermite were prepared by ultrasonic dispersion method. The samples were characterized by SEM, TG‐DSC, and constant pressure combustion experiments. The results show that in quaternary thermite, adding CuO increases initial exothermic temperature, but increases exothermic heat in high‐temperature regions, and effectively reduces the activation energy of the thermite reaction. On the contrary, adding Mg reduces exothermic heat in the high‐temperature areas, but reduces initial exothermic temperature. After calculation, the quaternary thermite with the best exothermic performance is Al0.8Mg0.2/(MoO3)0.5CuO0.5. Its initial reaction temperature is only 614 °C, but the heat release is up to 2217 J/g. Its activation energy is only 106.7 kJ/mol, but the critical temperature of thermal explosion is up to 927.9 K. At the same time, Al0.8Mg0.2/(MoO3)0.5CuO0.5 has better combustion performance. During combustion, the flame is jet‐like, and the main products are Al2O3, Mo and Cu. This work provides a reference for studying the thermal safety and combustion performance of quaternary thermite.