Development of rGO doped alumina-based wear and corrosion resistant ceramic coatings on steel using HVOF thermal spray

Abstract

This study deals with the development of hard, wear-resistant ceramic-based coatings containing Alumina (Al2O3) doped with 0.8% Ceria (CeO2) and reduced graphene oxide (rGO, 0–0.2%) on 17-4 PH steel using High-Velocity Oxygen Fuel (HVOF) thermal spray process. The tribological response of the coatings were recorded using Universal Tribo Tester. The corrosion response of the coatings was studied using potentiostat galvanostat corrosion setup. The introduction of rGO to the Al2O3–CeO2 helps in reducing the coefficient of friction and better corrosion response in the coatings. The elastic modulus and nano hardness of Al2O3–CeO2-rGO coating are ≈101% and ≈ 87% higher than that of Al2O3–CeO2 coating, respectively. The specific wear rate of Al2O3–CeO2-rGO coating is reduced by ten times compared to that of 17-4 PH steel. The improved properties can be attributed to the dense microstructure of the coatings with the introduction of rGO and participation of rGO in the tribological process.