Phase Evolution of Ti 3 SiC 2 Annealing in Vacuum at Elevated Temperatures

The thermal decomposition of T i 3 S i C 2 in vacuum furnace up to 1500°C has been investigated. The results show that the mild decomposition of T i 3 S i C 2 commences at 1300°C and the higher the holding temperature, the larger the volatilization of Si atoms. The T i 3 S i C 2 decomposition occurs simultaneously on the surface and in the bulk. Four phases coexist at 1400°C and 1450°C and the Ti 5 Si 3 C x phase appears in the bulk and/or surface. Diffusion distance, rate, and volatilization of Si contribute to the porous structure and the presence of Ti 5 Si 3 C x . The evolution of furnace pressure reflects the decomposition kinetics of T i 3 S i C 2 .