The effect of temperature on the dry sliding wear behavior of HVOF sprayed nanostructured WC-CoCr coatings

The sliding wear properties of high-velocity oxygen-fuel (HVOF) sprayed nanostructured WC-CoCr cermet coatings against Al2O3 under dry friction at different temperatures were investigated using a pin-on-disk high-temperature tribometer. The microhardness data of the coatings were also statistically analyzed by using the Weibull distribution. The results showed that nanostructured coatings exhibited a mono-modal distribution under indentation load of 100 g, and a bimodal distribution under indentation load of 300 g. With increasing test temperature, the coatings showed an increase in wear rate. The evolution of the sliding wear mechanism of the coatings with the increase of the temperature was extrusion deformation at room temperature, carbide particle pull-out, oxidation wear and adhesive wear at 200 °C, and a combination of binder extrusion and fatigue delamination coupled with oxidation wear at 500 °C.