Wear resistance mechanisms of near-nanostructured WC-Co coatings

Dense near-nanostructured WC-Co coatings with hardness above 1400 HV0.3 were fabricated by high velocity oxy-fuel spraying using the in situ synthesized WC-Co composite powders containing VC and Cr3C2. The carbide additives inhibited WC coarsening effectively and facilitated formation of the clustered structures consisting of WC grains and amorphous Co. Owing to the dragging effect of clusters, the connected WC particles are much more difficult to be peeled off than the isolated WC particles. Therefore, the wear resistance of the near-nanostructured coating was significantly enhanced. The mechanisms proposed the importance of interfacial characteristics for the wear resistance behavior of the cermet coatings.