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.