Effect of WC particle size on WC-10Co-4Cr HVOF coating properties

Previous literature on the use of WC nanoparticles in HVOF coatings has been limited and occasionally contradictory. This is primarily attributed to varying degrees of undesirable decarburization and decomposition of WC nanoparticles during the coating process. Uncontrolled, these changes significantly degrade coating properties. In this current research, the attributes of WC-10Co-4Cr HVOF coatings containing WC nanoparticles and microparticles with almost similar, controlled and minimized decarburization were compared. To minimize undesired decarburization, optimal HVOF parameters were employed. It was observed that the use of WC nanoparticles resulted in enhanced hardness and wear durability of these coatings. The enhanced properties of this nanocoating are attributed to a reduction in porosity size and count, improved arrangement and distribution of WC nanoparticles, and a decrease in the interparticle spacing.