Reduced Graphene Oxide Films to Enhance the Tribological Performance of Micro-arc Oxidation Coatings

Although the microarc oxidation (MAO) technique can improve the properties of metals, there is still room for improvement in the tribological properties of MAO coatings. In this study, reduced graphene oxide (rGO) films were successfully prepared on the surface of MAO coatings using high-pressure ethanol vapor, which significantly improved the tribological properties of MAO coatings. The microscopic morphology of the rGO/MAO coatings was analyzed by scanning electron microscopy (SEM), and the sealing effect of the rGO coatings on the micropores of the MAO coating surface was further confirmed by a 3D profile scanner. Then, X-ray photoelectron spectroscopy (XPS) was used to investigate the changes in the GO structure of the MAO coating surface before and after high-pressure ethanol vapor reduction. Finally, tribological experiments were conducted to evaluate the tribological properties of rGO/MAO. The results showed that the coefficient of friction (COF) of the prepared rGO films was reduced by 45.13% and the wear resistance of the MAO coatings was extremely improved. This innovative approach provides a feasible solution for the development of composite coatings, which can be widely applied in the field of coating preparation.