3.2. Powder metallurgy (PM) route
For solid-state PM route, the reinforcement and metal powder are mixed and consolidated by hot pressing, high-temperature and high-pressure (HTHP) or spark plasma sintering (SPS). HPHT produces the highest thermal properties in the case of C/metal and diamond/metal composites [32]. SPS is favorable for the suppression of interfacial reaction due to the lower sintering temperature and fast heating rate [33]. Metal coating on the filler is necessary to assure homogeneous distribution of reinforcement and suppress the interfacial reaction. However, PM is limited to simple-shaped components with low content of reinforcement.