Manganese as fuel in slow-burning pyrotechnic time delay compositions

Abstract

Manganese metal was evaluated as a fuel for slow-burning delay compositions press-filled in aluminium or compaction-rolled in lead tubes. Oxides of antimony, bismuth, copper, manganese and vanadium were considered as oxidants. Measured burn rates for binary mixtures varied between 5 and 22 mm s 1 but slower burning ternary and quaternary compositions were also found. The addition of fumed silica to the Mn/MnO2 system had little effect on the propagation rate but a low level addition of hollow glass sphere significantly reduced the burn rate. Mn MnO2 mixtures showed reliable burning over a wide stoichiometric range. In this system the fuel and the oxidant share a common metal. They combine to form the more stable intermediate oxide (MnO) releasing considerable quantities of heat in the process.