Phase and structural transformations and mechanism of propagation of self-propagating high-temperature synthesis in a V2O5-Al mixture

Physicochemical transformations upon heating and combustion of an Al−V₂O₅ mixture are investigated. It is established that the process proceeds in a one- or two-wave regime, depending on the method of initiation. Concentration profiles of the starting and intermediate products are obtained in various zones of the wave of self-propagating high-temperature synthesis. The presence of vanadium radicals in the preflame zone is detected. It is proposed that the main feature of transformation of the mixture in the processes of a low-temperature wave is chain autocatalysis. It is established that, at initial temperatures in vacuum or upon dilution of the mixture, a low-temperature wave stabilizes near a high-temperature wave, thus entering a “satellite” regime. Institute of Problems of Combustion, Almaty 480012. Translated from Fizika Goreniya i Vzryva, Vol. 33, No. 6, pp. 36–47, November–December, 1997.