Activated combustion of a silicon–carbon mixture in nitrogen and SHS of Si$_3$N$_4$–SiC composite ceramic powders and silicon carbide

It is established that Si$_3$N$_4$–SiC composites with a mass content of SiC 5–60% and a dominating content of the $\beta$-modification of silicon nitride can be produced by interaction of the components in the Si–C–N$_2$ system in the combustion regime. It is found that the fraction of $\alpha$-Si$_3$N$_4$ can be increased by diluting the starting mixture with the end products, but this leads to the occurrence of a certain amount of unreacted silicon in the products. It is shown that the use of chemical activation allows one to perform a single-stage synthesis of Si$_3$N$_4$–SiC composites with any contents of the individual components (from 0 to 100%), including pure carbide silicon.
Si$_3$N$_4$/SiC