Wettability and interfacial reaction in SiC/Ni plus Ti system

Wettability and interfacial reactions in both SiC ceramic/pure Ni system and SiC ceramic/Ni plus Ti system were studied. The contact angle was determined by high temperature photography. The microstructure and composition of the interfacial region were analyzed. Under the applied experimental conditions, the contact angle of SiC/pure Ni system at 1350degreesC in vacuum is about 86degrees. The contact angle slightly decreases with the prolonging of time of the test at 1350degreesC. The interfacial reactions take place during the test. The reactions facilitate the wetting. The wettability of the system is improved by adding active element titanium into the metallic phase. The contact angle decreases with the increasing of content of the additive within the tested range. Moreover, this effect becomes more remarkable with the prolonging of reaction time at high temperatures. This can be explained by the fact that titanium accumulates at the wetting interface and facilitates the interfacial reactions, resulting in an increase of the driving force of wetting. (C) 2002 Kluwer Academic Publishers.