Microstructure and mechanical behaviors of in situ TiC particulates reinforced Ni matrix composites

In situ synthesis of 20 vol% TiC–Ni composites using the medium frequency induction melting–casting technology was investigated. The final product was composed of TiC and Ni. As the only second phase, TiC particles were homogeneously distributed in the matrix with two kinds of morphologies, i.e. large cubic and fine fibrous. It is identified that the cubic TiC is a primary phase, while the fibrous is a eutectic phase. During the reaction process, Ni was served as diluents, Ti and C as reactants and TiC as a product. The results show it is feasible to in situ form TiC in the molten Ni. The product exhibits relatively high hardness (450 HV0.5, 41.5HRC), moderate yield strength (σ0.2 385 ± 3 MPa), and high ultimate tensile strength (σb 591 ± 5 MPa), as well as good transverse flexural strength (1362 ± 12 MPa).