On the Influence of Powder Feed Structure on Wear Properties of HVOF Sprayed WC/Co Hardcoatings

This paper compares the wear properties of HVOF-sprayed WC/12Co hardcoatings produced from different powder feedstock materials, including conventional, nanophase, and mixed powders. The mixed or multimodal feed powder is designed to minimize the amount of material that goes through a high temperature cycle during spraying, thus potentially limiting the extent of decarburization in the resulting coating. As will be shown, decarburization is indeed minimal in a multimodal coating, which translates into exceptional resistance to abrasive and sliding wear. Another favorable factor is the ability to increase the volume fraction of hard WC phase in such a coating, thereby further enhancing its wear resistance.