Corrosion protection of Ti6Al4V by a composite coating with a plasma electrolytic oxidation layer and sol gel layer filled with graphene oxide
Abstract Seawater is regarded as the most corrosive natural environment, and can lead to serious corrosion, friction, and their collaborative effects. In this work, composite films were fabricated by combining a graphene oxide (GO) modified hybrid sol gel (sol gel/GO) layer and plasma electrolytic oxidation (PEO) layer for corrosion protection. XRD, TFIR, XPS, and Raman analyses were used to prove the covalent functionalisation between the GO and silane coupling agents. The results showed that the micropores in the PEO film were filled with the GO/sol gel layer. Electrochemical tests indicated that the addition of GO at different concentrations could significantly improve the corrosion performance of the substrates through the good barrier property of the GO nanosheets. Moreover, the enhanced wear resistance of the GO/sol gel layer during tribocorrosion tests could be attributed to the solid lubrication property of the GO nanosheets.