Synthesis and tribological behavior of electroless Ni–P–WC nanocomposite coatings

Ni–P–WC nanocomposite coatings were prepared by electroless deposition with embedded nanometer-sized WC particles. The microhardness and tribological properties of the nanocomposite coatings, in as-deposited and annealed states, were investigated and compared with conventional Ni–P coating. It was seen that Ni–P–WC nano-coatings exhibited a low friction coefficient, high hardness, and heat-treatment of these coatings at 400 °C for 1 h could further increase the microhardness and wear resistance. This improvement was attributed to the existence of WC nano-phase grains and the crystallization of a hard Ni3P phase. The abrasive wear was superior for the Ni–P–WC nano-coatings, while the combined adhesive and fatigue mechanism was better for the conventional Ni–P coating.