FABRICATION OF Ti/SiC MMCs BY VACUUM HOT PRESSING WITH AID OF HYDROGEN

In order to alleviate the severe interface reaction, which is likely to occur during the fabrication of continuous SiC fiber reinforced titanium matrix composite, hydrogen was temporarily introduced in the fabrication to lower the consolidation temperature of Ti/SiC composites in the present work. Effects of different fabrication conditions, with or without hydrogen, on the bonding state and the matrix microstructure were investigated. In-situ hydrogenation method was found to larpely improve the interface bonding of the composite, and full consolidation could be achieved at 750 or even 700° C more than 100°C lower than the normal fabrication temperature of Ti/SiC composite, which consequently reduced the interfacial reaction layer between Ti matrix and SiC fiber. Different hydrogenation condition led to different matrix microstructure. In order to avoid the embrittling effect of residual hydrogen on the composite,Ti/SiC composite needs to be held in vacuum at the fabrication temperature for longer time after consolidation.