Rolling contact fatigue behavior of laser cladded WC/Ni composite coating

The aim of this paper was to address the fatigue behavior and mechanism of the laser cladded WC/Ni composite coatings under rolling contact condition. The coating was deposited by a 4 kW continuous wave CO2 laser system. Rolling contact fatigue tests were conducted under lubrication condition at room temperature. The surface morphologies of the entire wear track for different rolling cycles were observed and recorded. Experimental results showed that the surface crack behaviors were strongly dependent on the location on the wear track. It was identified that spalling was the main fatigue failure mode of the coating under rolling cycles. The joining of surface cracks and the subsurface branched cracks led to the formation of the spall. The depth of the main subsurface crack was influenced by the distribution of the WC particles in the coating.