PHASE REACTION AND DIFFUSION PATH OF THE SIC TI SYSTEM/

Bonding of SiC to SiC was conducted using Ti foil at bonding temperatu res from 1373 to 1773 K in vacuum. The total diffusion path between Si C and Ti was investigated in detail at 1673 K using Ti foil with a thi ckness of 50 mu m. At a bonding time of 0.3 ks, TiC at the Ti side and a mixture of Ti5Si3Cx and TiC at the SiC side were formed, yielding t he structure sequence of beta-Ti/Ti + TiC/Ti5Si3Cx + TiC/SiC. Furtherm ore, at the bonding time of 0.9 ks, a Ti5Si3Cx layer phase appeared be tween SiC and the mixture of Ti5Si3Cx and TiC. Upon the formation of T i3SiC2 (T phase) after the bonding time of 3.6 ks, the complete diffus ion path was observed as follows: beta-Ti/Ti + TiC/Ti5Si3Cx + TiC/Ti5S i3Cx/Ti3SiC2/SiC. The activation energies for growth of TiC, Ti5Si3Cx, and Ti3SiC2 were 194, 242, and 358 kJ/mol, respectively.