Performance study of abrasive wear and erosive wear of WC-12Co coatings sprayed by HVOF

Abstract

WC-Co cermets have been used traditionally as wear-resistant materials. Recent work has shown that nanostructured cermets offer improved properties over their conventional counterparts. This work examines the performance of such conventional and nanostructured materials in the form of coatings deposited by high velocity oxy-fuel(HVOF) thermal spraying. WC-12Co coatings were deposited under identical conditions using nanostructured, multimodal and conventional WC-12Co powder feedstocks. The phase constituents of the feedstock powders and the coatings were analyzed by XRD. Abrasive and erosive wear resistances of coatings were carried out on wet sand rubber wheel abrasion tester and suction & jet blasting machine respectively. The characterizations of spraying feedstock powders, microstructure and surface micrographs of the prophase and anaphase attrition & erosive surfaces were analyzed by SEM. The results indicated that: microstructures of nanostructured and multimodal WC-12Co coatings prepared by HVOF are dense with little porosity, and their microhardness values are obviously higher than conventional WC-12Co coating, though Nano WC decomposed much more server than conventional WC did during spraying. As well, it was found that nanostructured and multimodal WC-12Co coatings exhibited better abrasive and erosive wear resistance in comparison with conventional one.