Flame propagation in two-component aluminum–boron gas suspensions

Flame propagation in gas suspensions of boron particles, in boron–aluminum mixtures, and in aluminum–inert additive mixtures is experimentally studied. General features of the process are revealed, and flame-propagation velocities in two-component boron-containing mixtures are measured. It is shown that, in the considered range of parameters of the suspensions, addition of boron to aluminum retards flame propagation. The decrease in the flame-propagation velocity in boron–aluminum mixtures is more pronounced than in analogous aluminum–inert additive mixtures. The latter can be attributed to oxygen consumption by boron in relatively low-exothermal reactions yielding boron suboxides and, correspondingly, oxidant deficiency for the leading process of aluminum combustion.