Improved corrosion resistance of MAO coating on Mg-Li alloy by RGO modified silanization.

The inherent micropores and microcracks in the micro-arc oxidation (MAO) film on the surface of Mg-Li alloy limit the corrosion resistance of the film in corrosive environments. In this work, the double-layer micro-arc oxidation/3-glycidoxypropyltrimethoxysilane (KH560) composite film was prepared on the surface of the LA103Z Mg-Li alloy by MAO and silanization treatments. Based on this, the modification with reduced graphene oxide (RGO) to the KH560 film was studied and the corrosion resistance of the film was investigated. The results show that the silane film prepared is uniform and complete which fills up the micropores and microcracks of the MAO film, enhancing the shielding effect of the film. Moreover, the RGO modification increases the thickness of the KH560 film and the corrosion resistance of the composite film significantly in 3.5 wt% NaCl solution. • The silane film fills up the micropores and microcracks of the MAO film, enhancing the shielding effect of the film. • The RGO increases the thickness of the KH560 film and the corrosion resistance of the composite film significantly. [ABSTRACT FROM AUTHOR]