Combustion of ultrafine aluminum in air

The paper reports results of studying the combustion of ultrafine aluminum (surface average diameter of particles is $\approx$ 0.1 $\mu$m) in a sealed bomb at an initial air pressure of 1 atm. The combustion proceeds in two stages, similarly to combustion in air. It is shown that during the two-stage combustion of ultrafine aluminum powder in the bomb, the mass concentration of chemically bound nitrogen in the final products increases by $\approx$ 20% in terms of aluminum nitride. An increase in nitrogen content in confined combustion validates the previously proposed mechanism of binding air nitrogen with participation of the gas phase during aluminum combustion.