Combustion of thermite mixtures based on mechanically alloyed aluminum-iodine material

Halogen-containing reactive materials could be used for mitigating the spread of hazardous, active biological microorganisms aerosolized as a result of explosion. Here we present experimental results on combustion of mechanically alloyed aluminum-iodine (Al·I₂) powder mixed with Fe₂O₃, CuO, MoO₃, Bi₂O₃, and I₂O₅. The mixtures were compacted into pellets and ignited with a CO₂ laser. High-speed video recording was used for observations. Mixtures of the Al·I₂ powder with Fe₂O₃ did not ignite, while mixtures of this powder with the other oxides exhibited a self-sustained propagation of the combustion front with similar burn rates. Comparison experiments with a finer, micron-sized Al powder have shown a more rapid combustion of mixtures based on metal oxides and, in contrast, a slower and unsteady combustion of Al/I₂O₅ thermite. These observations are interpreted based on the analysis of reaction mechanisms.