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

Abstract

In order to study the effect of fuel Mg and metal oxide CuO on the reaction of thermite, different proportions of Al-Mg alloys and MoO 3 -CuO metal oxides were prepared by mechanical ball milling, and then the samples of Al 1-x Mg x /(MoO 3 ) 1-x CuO x 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 Al 0.8 Mg 0.2 /(MoO 3 ) 0.5 CuO 0.5 . 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, Al 0.8 Mg 0.2 /(MoO 3 ) 0.5 CuO 0.5 has better combustion performance. During combustion, the flame is jet-like, and the main products are Al 2 O 3 , Mo and Cu. This work provides a reference for studying the thermal safety and combustion performance of quaternary thermite.

Hot Bridge-Wire Ignition of Nanocomposite Aluminum Thermite Synthesized Using Sol-Gel-Derived Aerogel with Tailored Properties for Enhanced Reactivity and Reduced Sensitivity

“…The addition of CuO to Al-Mg alloys in thermite reduces the activation energy of the reaction, with the best performance observed in Al 0.8 Mg 0.2 (MoO 3 ) 0.5 CuO 0.5 [69]. The addition of CuO to Al-Mg alloys increases the exothermic heat in high-temperature regions of the thermite reaction [69], while the addition of KClO 4 to Al/Bi 2 O 3 nano-thermite also reduces the activation energy, with Al/Bi 2 O 3 /10wt%-KClO 4 exhibiting the highest heat release among other samples [70], while the lowest activation energy was observed in Al/Bi 2 O 3 /30wt%-KClO 4 [70].…”

“…Diluted Fe 2 O 3 -2Al thermite system with alumina was found to suppress burning rate, peak temperature, and expelled mass, signifying potential cost-effective and controlled applications in thermal processes [74]. Therefore, the key factors determining the activation energy, heat of reaction, and fraction of energy feedback in thermite include the choice of fuel and oxidizer and thermodynamic and kinetic parameters [69,70,72,75]. These factors interact synergistically to exert their influence on the thermite reaction propagation, heat release, and combustion performance [69,72].…”

“…Therefore, the key factors determining the activation energy, heat of reaction, and fraction of energy feedback in thermite include the choice of fuel and oxidizer and thermodynamic and kinetic parameters [69,70,72,75]. These factors interact synergistically to exert their influence on the thermite reaction propagation, heat release, and combustion performance [69,72].…”

Study on combustion characteristics and pyrotechnic cutting effects of bimetal thermite Ni/Al/Fe2O3 system

“…The results indicated that as the Mg content increased, the ignition temperature plummeted from 450 °C to 220 °C, while the reaction activity experienced a significant improvement. Liu et al [19] analyzed the effect of fuel Mg and CuO on the reaction of thermite. The results demonstrated that in quaternary thermite, the addition of Mg diminished exothermic heat in the high-temperature areas and the initial exothermic temperature.…”

“…Liu et al. [19] analyzed the effect of fuel Mg and CuO on the reaction of thermite. The results demonstrated that in quaternary thermite, the addition of Mg diminished exothermic heat in the high‐temperature areas and the initial exothermic temperature.…”