Burn-rate studies with iron/potassium perchlorate heat pellets

A detailed study was conducted on factors which could possibly influence the burn rate of Fe/KClO₄ heat pellets. The primary variables studied included the composition, density, temperature, and thickness of the pellets. Heat powders from two commercial suppliers were characterized and the effect of Fe particle size was examined in limited tests. Substrate effects were also investigated. The burning process was monitored with a high-speed video analysis system. The substrate and pellet thickness had little effect upon the burn rate of heat pellets. The pellet density, composition, and Fe particle size, however, affected the burn rates significantly. By proper adjustment of these parameters, the burn rate of heat pellets can be affected. This, in turn, can be used to influence the rise times of thermal batteries that use this type of pyrotechnic heat source