The formation mechanism of TiC particles in TiC/Ni composites fabricated by in situ reactive infiltration

The firstly reported formation mechanism of TiC particles in TiC/Ni composites fabricated by in situ reactive infiltration process is presented. In this paper, the TiC/Ni composites were fabricated by in situ reactive infiltration and the formation mechanism of TiC particles during the process was investigated. The results show that the process includes two stages. In stage I, the Ti and graphite react and generate TiC _x (x < 1) particles, which grow on the graphite sheets and form multilayer or a single-layer stacking morphology, depending on the position of graphite sheets. In stage II, the C/Ti ratio, particle size and morphology of TiC _x particles are adjusted by the infiltrated metal through “dissolution–precipitation” process, and the final morphology of TiC particles in the metal matrix is decided by the initial C/Ti ratio, metal amount, and alloying elements.