6H→3C-SiC transformation in SiC-TiN powder mixture at high temperature

A 6H→3C transformation, which does not commonly occur at high temperatures, was observed in SiC. A 6H-SiC and TiN powder mixture was hot-pressed in a flowing Ar atmosphere. The starting 6H-SiC powder was completely transformed to 3C polytype above 2200°C, although 3C-SiC was not stable at this temperature. It was found that coexistence of N was essential for this 6H→3C transformation, and a small amount of Ti was detected in the transformed SiC grain. The results suggest that a solution of N or TiN in the SiC grain would transform the 6H-SiC to the 3C form.