Selection and Testing of Thermite Compositions for Pyrotechnic Devices

摘要

Thermite "gasless" compositions represent a subclass of materials offering the processability of pyrotechnic devices for different applications, such as space actuators (rotary hinge, pin pushers, pin pullers, etc.), with the high heat release and few gas products generated. In the present investigation thermite compositions, selected on the base of the analytical search, were examined with the aim of decreasing of the sensitivity to gravity effect and increasing of wet ability of the combustion products. Simultaneous DSC-TG analyses were performed for thermites both as powders and pressed tablets allowing examining parameters of the heat release, and thermal-physical characteristics of the compositions. Experimental study of the cylindrical samples combustion within stainless tubes shows the pressure-time history along with the temperature field on the external surface of the tubes. As expected, the analyzed compositions show the smooth temperature distribution along the steel tube. Impressive reduction of the gravity sensitivity was found for some compositions. Obtained results indicate that some of the selected compositions are perspective for use as a heat source in pyrotechnic devices for space applications.