Enhanced mechanical properties and oxidation resistance of NbC-Ni cermets via NbN addition

The mechanical properties and oxidation resistance of cutting tool materials are two important factors that can affect their performance. In this work, NbN was used as an additive to improve the mechanical properties and oxidation resistance of NbC-Ni cermets. The results demonstrated that the densification sintering temperature increased with increasing addition of NbN, with the optimized sintering temperature of NbC-Ni cermets containing 10 wt% NbN being 1480 degree celsius. The incorporation of NbN into NbC-Ni led to the formation of NbCN-Ni cermets. As a result of solution strengthening, the cermet transverse rupture strength (TRS) and hardness were considerably improved. However, the TRS and hardness decreased for the NbC-Ni cermets exceeding 10 wt% NbN owing to the increased porosity and grain growth. With increasing NbN content, the oxidation resistance of NbC-Ni cermets initially increased before decreasing. The best oxidation resistance of NbC-Ni cermets with 10 wt% NbN was due to the higher NbN content and dense structure.