Friction and Wear Characteristics of Multimodal WC-12Co Coatings Deposited by HVOF

In the present paper, two WC-12Co cermet coatings that have a multimodal structure and one WC-12Co cermet coating that has a submicron structure were deposited by high velocity oxygen fuel (HVOF) process, and the microstructure, porosity, phase structure and microhardness of the two coatings were analyzed by using scanning electron microscopy (SEM) and x-ray diffraction (XRD). The friction and wear characteristics of the two coatings were carried out on a ball-on-disc tribo-tester and the wear mechanisms of the two WC-12Co coatings were explored. Results show that the multimodal structured coating deposited by powders containing 30% nano-size WC-12Co particles had the lowest degree of decarburization during spraying and the highest microhardness. In addition, the multimodal structured coating deposited by the powders containing 50% nano-size WC-12Co particles had the lowest porosity and the highest wear resistance.