Combustion and Thermal Behavior of Selected Metallic Fuels Used in Pyrotechnic Compositions

Metal powders have both a high specific energy and a high energy density, which explains their widespread use in energetic materials (propellants, explosives and pyrotechnics). Pyrotechnic compositions are used extensively for both civilian and military applications. However, the combustion of pyrotechnics remains challenging to understand or predict due to the diversity of the components and the wide range of parameters that affect their results. Therefore, ongoing research efforts worldwide aim to investigate the combustion mechanisms of pyrotechnic compositions to improve their performance. In this review, studies on the ignition and combustion mechanisms of four metal powders (Al, Mg, Fe and B) are discussed. Moreover, their use as fuel in pyrotechnic systems is reported, as well as the combustion performance and energy release of the pyrotechnic mixtures. Additionally, some mixtures composed of fluorinated oxidizers and Al, Mg and B are also presented. Thermal analysis methods such as DSC and TG are used to obtain the thermal behavior of the pyrotechnic compositions. Furthermore, parameters such as particle size and the equivalence ratio that affect the performance of pyrotechnic mixtures and those that remain little studied are reported in this review.