Microhardness and dry sliding wear behaviour of HVOF sprayed WC-Co-Cr+ graphene nanoplatelets coating

Abstract

In this study, coating of WC-10Co-4Cr with the incorporation of 2 wt%, 3 wt%, and 4 wt% graphene nano-platelets (GNPs) were created on an IS-2062 steel substrate by employing high-velocity oxy-fuel (HVOF) technique. Cross-sectional Vickers' microhardness and dry siding wear of coated substrate against hardened EN32 steel disc were investigated after successful coating deposition in the range 220–230 µm. Furthermore, the worn-out surface was characterised using optical images, weight loss, and the coefficient of friction. The experimental results show that the hardness of IS-2062 steel has been increased by a factor of 5. The weight loss of specimens during dry sliding wear is primarily caused by micro-ploughing, lips formation, and breaking, as observed from the optical images.Weight loss during sliding wear was found to decrease as the percentage of GNPs increases in WC-10Co-4Cr feedstock powder. In terms of higher microhardness and low wear rate, the coating configuration WC-10Co-4Cr+ 3% GNPs provides the best results for practical applications.