Titanium enhanced ignition and combustion of Al/I2O5 mesoparticle composites

Aluminum (Al) is widely used in thermites, and iodine pentoxide (I2O5) is a strong oxidizer that can release gas phase iodine. The result is a potentially very powerful and effective energetic composite with biocidal properties. However, the alumina coating on the Al presents a diffusion barrier that increases the ignition temperature. In this paper, nano titanium powders (nTi) were added at various mass ratios to Al/I2O5 and a composite mesoparticle was assembled by electrospray. Combustion studies showed that nano Ti can enhance the reactivity of Al/I2O5 thermites significantly with increases in pressure, pressurization rate and dramatic decreases in burn time. Part of this behavior can likely be attributed to less sintering enhancing the completeness of reaction in the Ti added cases. Addition of titanium to aluminum was found to have a significant impact on ignition and when Al is replaced with Ti, the ignition temperature was similar to 300 degrees C below that of the corresponding aluminum thermite. These results show that titanium can be used as a fuel to tune energetic behavior and iodine release temperature and in some ways superior to aluminum. (C) 2019 Published by Elsevier Inc. on behalf of The Combustion Institute.