Comparative Study on the Tribological Performance of Titanium Carbide (TiC) and Tantalum Carbide (TaC) Reinforced Nickel-Based Composites at Room Temperature and 600 °C

The selection of suitable reinforcement is crucial for nickel (Ni)-based composites to obtain required tribological property. The tribological property of in-situ titanium carbide (TiC)/Ni and tantalum carbide (TaC)/Ni composites with 65 vol.% Ni at room temperature (RT) and 600 °C was compared in this work. The TiC/Ni composites with finer grains size exhibit higher hardness (361 HV) than that (246 HV) of TaC/Ni composite. At 600 °C, TiC/Ni composite presents better oxidation resistance than TaC/Ni composite. The tribolayer is generated on both TiC/Ni and TaC/Ni composites at RT and 600 °C. The tribolayer on TiC/Ni composite comprises TiO2 and nickel oxide (NiO), whereas Ta2O5 and NiO are generated on TaC/Ni composite. The higher hardness and oxidation resistance contribute to the slighter abrasive, oxidative and delamination wear of TiC/Ni composites. As a result, the wear rate of TiC/Ni composites is 1.79 × 10−5 (RT) and 1.26 × 10−4 mm³/N·m (600 °C), which are much lower than 2.71 × 10−5 (RT) and 2.18 × 10−4 mm³/N·m (600 °C) of TaC/Ni composites. Whereas, the more continuous tribolayer rich in Ta2O5 and SiO2 solid lubricating agents makes the friction coefficient of TaC/Ni composites is 0.54 (RT) and 0.59 (600 °C), lower than 0.70 (RT) and 0.77 (600 °C) of TiC/Ni composites.