Activated combustion of the SiO$_2$–Al–C system and synthesis of SiC/Al$_2$O$_3$ composite powders

The mechanism of initiation and combustion of the 3SiO$_2$–4Al–3C system is studied under conditions of activation of the combustion reaction by a high-energy additive of Al + $\alpha$KNO$_3$. It is shown that combustion of this system is possible only when a certain quantity of the additive is introduced into the starting mixture. The mechanism of activation of the reaction is established, and the processes involved in the reduction stage of the combustion are shown to play a leading role in the reaction. Optimal conditions for synthesis of a SiC/Al$_2$O$_3$ composite powder containing SiC fibers are determined.