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 SiCf/Ti mmcs using either TiB2/C-coated or uncoated SiCf. There is only limited interfacial reaction after short-term thermal exposure during vhp manufacture of SiCf/Ti-6Al-4V mmcs using TiB2/C-coated SiCf. 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. © 1994