Enhanced Wear Resistance of In-Situ TiC/Ni Composites by Doping Ni@CeO₂ Particles

The in-situ TiC/Ni composites with different Ni@CeO₂ mass fraction were fabricated by pressureless reactive sintering method, and the effect of Ni@CeO₂ on the tribological perfermance of composites were studied. The Ce dissolved into TiC particles, leading to the increased hardness from 632 HV to 701 HV, as the Ni@CeO₂ mass fraction increased from 0 to 0.6%. The introduction of 1% Ni@CeO₂ results in diminished structural integrity, inducing the reduced hardness to 646 HV. The wear mechanism of TiC/Ni composites included delamination wear, oxidative wear, adhesive wear and abrasive wear. As the Ni@CeO₂ mass fraction increased from 0 to 0.6%, the wear mechanism changed to delamination wear, oxidative wear and adhesive wear, due to the higher hardness and oxidation resistance. The continuous and dense tribolayer was formed on composites with 0.6% Ni@CeO₂, and the delamination and oxidation wear were diminished, leading to the lower friction coefficient and wear rate. The addition of Ni@CeO₂ presented obvious effect on the hardness and oxidation resistance of composites, which was crucial to the formation of tribolayer on composites during the friction process. Therefore, the tribological performance of TiC/Ni composite could be effectively enhanced by adding suitable amount of Ni@CeO₂.