Microstructure and Wear Resistance of In Situ Synthesized (Ti,V)C Reinforced Nickel Matrix Composite Coatings

In situ synthesized (Ti, V)C reinforced Ni-based composite coatings were prepared using laser cladding method. The phase composition, microstructure, hardness, and wear resistance of the composite coatings with different carbide contents were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), hardness tester, and wear tester. The evolution process of the melt pool was elucidated. In comparison with the Ni45 laser-clad coating, the microhardness and wear resistance of the Ni-based composite coatings containing (Ti, V)C were significantly enhanced. The best wear resistance and highest average hardness of 835.9 HV of the composite coatings was achieved at a design content of 10 wt.% of (Ti, V)C. Compared to the Ni45 coating, the wear resistance increased from 1.6 to 17.1 min/mg, an improvement of approximately 9.76 times. First-principles calculations were employed to assess the mechanical properties, anisotropy, and electronic properties of the composite ceramic phase (Ti, V)C. Hardness calculations were conducted using a predictive model. The computational results indicated that (Ti, V)C exhibits strong covalent bonding characteristics, with a calculated hardness of 3235 HV exceeding that of TiC and VC.