Interface microstructures in Ti-based composites using TiB2/C-coated and uncoated SiCf after short-term thermal exposure

The extent of interfacial reaction after short-term thermal exposure during vacuum plasma spraying (vps) and vacuum hot-pressing (vhp) of Ti-based metal-matrix composites (mmcs) using TiB₂/C-coated and uncoated SiC fibres has been investigated by a combination of scanning and transmission electron microscopies. There is no interfacial reaction after short-term thermal exposure during vps manufacture of SiC_f/Ti mmcs using either TiB₂/C-coated or uncoated SiC_f. There is only limited interfacial reaction after short-term thermal exposure during vhp manufacture of SiC_f/Ti-6Al-4V mmcs using TiB₂/C-coated SiC_f. In the initial stage of the interfacial reaction, TiB needles are formed by preferential nucleation and growth at β particles and grain boundaries in the Ti-6Al-4V matrix.