BiVO4 bimetallic oxide thermites with high temperature particle swarm flame

Abstract

Thermites has garnered significant attention due to its high energy density and elevated reaction temperature. However, in most cases, thermites reactions predominantly generate heat and high temperatures while yielding less gas production. Although Al/Bi2O3 exhibits abundant gas generation, it demonstrates lower heat release and is too sensitive. In this study, bismuth vanadate (BiVO4) is introduced as the oxidizer in thermites for the first time. Al/BiVO4 exceeds both Al/ Bi2O3 and Al/V2O5 in terms of jetting distance, and the maximum pressure attained by Al/BiVO4 is nearly double that of Al/ Bi2O3. Additionally, we investigate the reaction mechanism of the Al/BiVO4 system by means of thermal reaction pathway analysis and characterization of combustion and thermal analysis products. This study unveils a distinctive reaction mechanism during the combustion of Al/BiVO4, with bismuth undergoing reduction prior to vanadium. Throughout the entire reaction process, gaseous substances are forcefully released, and the high-temperature solids enhance the generation of gaseous products, resulting in the formation of a flame characterized by a high-temperature particle swarm. The impressive high temperature particle swarm flame and significant pressure output performance and flame jetting distance of the Al/BiVO4 system confer advantages to its ignition capability. We posit that Al/BiVO4 holds great potential for various applications in propellants, explosives, and pyrotechnic products.