Tailoring high WC addition and crack-free Ni-WC coatings by PTAW: Establishing the relationship between the WC type, its retention and the wear resistance of coatings

Crack-free Ni-WC composite coatings with 60 wt% WC were prepared by adjusting the process parameters of PTAW. The effect of WC types on the friction and wear behaviour was evaluated using ball-on-disc friction test at room temperature. Cast WC particles were gradually worn from their edges, while the carbothermally reduced (C-R) WC particles began to be peeled off along the interface of their internal particles. The wear rate of Ni-WC coating is positively linearly correlated with dissipated energy, but negatively linearly correlated with the retained content of WC particles in the wear track. Compared to C-R WC, cast WC provided lower friction dissipated energy, a wear rate reduction of 10.24–68.32 %, and a hardness increase of 49.89 % for coatings.