Influence of WC Particle Morphology on the Microstructure and Performance of Laser-Cladded Ni-Based WC Composite Coatings on 0Cr13Ni5Mo Steel

Ni-based WC composite coatings are widely used to protect hydraulic components, yet the role of WC particle morphology in binder-phase strengthening remains unclear. In this study, two Ni40-based coatings containing 55 wt.% WC were laser-cladded on 0Cr13Ni5Mo steel under identical conditions using either rough spherical WC coating (RWC) or smooth spherical WC coating (SWC). Both coatings were mainly composed of γ-Ni, residual WC, W2C, carbides, and borides. Although the rough WC particles showed about 38% lower intrinsic hardness than the smooth WC particles, the RWC exhibited a 25% higher binder-phase hardness and a 47% higher overall coating hardness. Accordingly, compared with the SWC, the RWC reduced the specific wear rate by about 33% under water-lubricated sliding. In slurry erosion, the RWC consistently showed lower erosion rates and less severe surface damage. The improved performance is attributed to the greater dissolution of rough WC during laser cladding, which strengthened the Ni-based binder and provided more stable support for the hard phases. These results demonstrate that tailoring WC particle morphology is an effective strategy for designing wear- and slurry erosion-resistant Ni-based laser-cladded coatings.