REACTION-MECHANISM BETWEEN SIC CERAMIC AND TI FOIL IN SOLID-STATE BONDING

The solid state bonding of pressureless-sintered (PLS) SiC to SiC using Ti-foils (50 mu m, 20 mu m and 8 mu m) were conducted at the bonding temperatures ranging from 1373 to 1673 K for 0.3 to 144 ks in vacuum. The total diffusion path, formation process of reaction phases and the reaction mechanism were examined. At a bonding temperature of 1673 K for 0.3 ks, granular TiC next to Ti and a mixture of Ti5Si3Cx + TiC phases next to SiC were formed. Further, the Ti5Si3Cx Single phase appeared between SiC and the mixture of Ti5Si3Cx + TiC at the bonding time of 0.9 ks. Upon the formation of Ti3SiC2 (T phase) after the bonding time of 3.6 ks, the complete diffusion path was observed as follows: SiC/Ti3SiC2/Ti5Si3Cx/Ti5Si3Cx + TiC/TiC/Ti. At a longer bonding time, TiC and Ti5Si3Cx were consumed and only the Ti3SiC2 and TiSi2 phases were detected in the reaction zone.