Tribological behaviour of plasma-sprayed WC coatings with and without laser remelting

In this paper, the tribological properties of plasma-sprayed WC–Co coatings are studied, both before and after remelting of the coatings with a CO2 laser. The coatings were deposited onto steel substrates. The laser treatment induced changes in porosity, microhardness, coating–substrate adherence and wear resistance in dry and lubricated contact. The results demonstrate that laser remelting of plasma-sprayed WC–Co coatings improve their microstructure, and increase the microhardness and coating–substrate adherence. Both materials, treated and untreated, present a dry sliding wear behaviour that matches satisfactorily with Czichosʹ model, and the friction coefficient is very similar for the two materials; however, the remelted coatings are more wear resistant under dry contact conditions.