Effects of Mg Al Alloy Powder on the Combustion and Infrared Emission Characteristics of the Mg Al PTFE Viton Composition

Metal-Fluorocarbon compositions are the pyrotechnic formulations which have been widely used in infrared decoy flares to protect aerial targets from infrared guide missile seekers. In this work, the effect of Mg-Al alloy powder (i.e. the particle size and the content) on the combustion and the infrared emission characteristics (i.e. the infrared emission distribution and the infrared radiance) of the pyrotechnic composition based on Mg-Al alloy, polytetrafluoroethylene (PTFE) and Viton rubber are described. The results show that the high burning rate (with the values of 4.0 mm.s-1 to 10.0 mm.s-1, depend on the compression density) of this composition is achieved with a high content of Mg-Al alloy or when using fine Mg-Al alloy particles as well as coarse PTFE particles. On the other hand, the infrared emission radiance (in the wavelength range of 2.5 μm to 5.0 μm) of Mg-Al/PTFE/Viton composition reaches maximum values (i.e. 17.7 W.cm-2.Sr-1 and 21.0 W.cm-2.Sr-1 with the size of Mg-Al particles are 20 μm and 120 μm, respectively) at 60 wt% Mg-Al alloy. Finally, the Mg-Al/PTFE/Viton composition has a similar combustion and emission characteristics as the Mg/PTFE/Viton composition.