Enhanced corrosion and wear resistances by graphene oxide coating on the surface of Mg-Zn-Ca alloy

The poor corrosion and wear resistances hinder the industrial applications of magnesium and its alloys. In this paper, a new graphene oxide (GO) coating is fabricated on the surface of extruded Mg-Zn-Ca alloy, via the silane coupling agent. The GO coating has fully covered the Mg substrate through the chemical reactions, and formed an overlapped multilayer structure by interlocked effects. Electrochemical measurements indicate that the anti-corrosion performance can be remarkably improved by silane/GO coating, because the stable covalent bonds within the coating effectively restrict the penetration of electrolyte into the Mg surface, representing an excellent corrosion barrier effect. The GO coating drastically promotes the wear resistance, due to the superior bonding between the Mg substrate and GO sheets with high hardness and good lubricant effect.