Influence of Critical Parameter on Microstructure and Properties of WC Coatings by Plasma Spraying

WC composite coatings were prepared by atmospheric plasma spraying technique (APS) at different critical plasma spraying parameters (CPSP), and the influence of CPSP on the microstructure, phases, mechanical and tribological properties of the WC coatings were discussed. Microstructure and phases of the WC coatings were examined using scanning electron microscope and X-ray diffraction. The tribological behaviors of the WC coatings were investigated on a ball-on-disk tribometer. The results show that the CPSP played an important role in controlling the thermophysical behavior of powder. The microstructures, mechanical and tribological properties of the WC coatings were significantly improved by reducing CPSP. The results confirmed that the high-quality WC coatings could be fabricated by APS using optimized spraying parameters. The enhanced mechanical and tribological properties of APS coatings were comparable to those prepared by the high velocity oxygen fuel (HVOF).