Combustion and Flame, Vol.200, 296-302, 2019
On the promotion of high temperature AP decomposition with silica mesoparticles
Silica particles are known to enhance the combustion of aluminum (Al) and ammonia perchlorate (AP) based energetic materials although the role of silica remains unknown. In this paper, AP/SiO2 mesoparticles ((AP/SiO2)(m)) and Al/(AP/SiO2)(m) composite particles were prepared and the thermal properties/reactivity evaluated. Composites with 7 wt% SiO2 have a reactivity similar to 7 times higher than that of Al/AP. The ignition temperature of Al/(AP/SiO2)(m) was also found to be similar to 100 degrees C lower compared to that of Al/AP. The thermal decomposition process of (AP/SiO2)(m) and Al/(AP/SiO2)(m) composite particles were investigated using both low and high heating rates. During slow heating, with the addition of silica, the decomposition of AP transitioned from a slow two-stage to a rapid one-step process. At high heating rate, the release temperature of CIO2 and O-2 from AP is below similar to 400 degrees C, while for (AP/SiO2)(m) case, the peak release temperature is much higher at similar to 650 degrees C, when Al NPs reach its melting point and are ready to react. This may explain why Al/(AP/SiO2)(m) shows higher reactivity than Al/AP composite particles. (C) 2018 Published by Elsevier Inc. on behalf of The Combustion Institute.