Development of Wear Resistant Coating on Steel Using HVOF Thermal Spray

Hard and dense ceramic coatings deposited on the surface provide an ideal solution to the poor tribological properties exhibited by some popular stainless steels like 17-4 PH. This steel is widely used in nuclear, fertilizer, food processing, marine industries under extreme environmental conditions. The present study focuses on the development of alumina (Al2O3)-ceria (CeO2)-reduced graphene oxide (rGO)-based coatings on the surface of 17-4 PH steel using High Velocity Oxygen Flame (HVOF) thermal spray process. The coating is developed using an oxyacetylene flame. The elastic modulus and nano hardness of the rGO-based coatings are higher than that of Al2O3–CeO2 coating and the substrate, and the specific wear rate is reduced by 10 times compared to the steel at 50N load. Further, the physical properties of the coatings in terms of density and surface roughness are reported. The improvement in the properties of the coatings can be attributed to addition of rGO in the Al2O3–CeO2 matrix, which helps in microstructure refinement and lubricating effect introduced by rGO in the coatings.