Reaction mechanism and friction behavior of an in-situ Ti/B4C composite synthesized by spark plasma sintering

Ceramic-reinforced Ti matrix composites were prepared by in situ spark plasma sintering (SPS). The reaction products and reaction mechanisms during sintering were studied by controlling the powder mixing degree. The wear resistance and wear mechanism of the composites were also studied. A large amount of un-reacted B4C remained in the mechanically-mixed group after SPS. Thermodynamic calculations and kinetic diffusion analysis showed that the outer layer of the reinforcement phase was TiB whiskers, and the interior was mainly composed of granular TiC, with a small amount of TiB and TiB2. The same reactions occurred in the ball-milled group, but they were more complete. The wear tests showed that the SPS samples after ball milling had higher wear resistance due to their more uniformly distributed reinforcing phase.