Improvement on corrosion resistance of micro-arc oxidized AZ91D magnesium alloy by a pore-sealing coating

Micro-arc oxidation is a low-cost and environmentally friendly technology for improving the corrosion resistance of magnesium alloys. However, the inherent porous structure limits the application of magnesium alloy micro-arc oxidation coatings in corrosion resistance. Herein, we investigated the corrosion resistance and friction resistance of the magnesium alloy micro-arc oxidation coating after being sealed by hydrothermal treatment and heat treatment. SEM, FTIR, XRD and XPS were performed to investigate the surface morphology and chemical composition of the prepared coating. The potentiodynamic polarization curve and electrochemical impedance spectroscopy confirmed that the prepared sample has good corrosion resistance in 3.5 wt% NaCl aqueous solution. In addition, the samples with coating also exhibit good friction resistance. After friction test, the samples still maintain good corrosion resistance. This method not only promotes the application of magnesium alloys in corrosive environments, but also has great potential for industrial production. (c) 2021 Elsevier B.V. All rights reserved.

Automated summary

The study improved the corrosion resistance and friction resistance of magnesium alloy micro-arc oxidation coatings by sealing with hydrothermal treatment and heat treatment, enhancing their performance in 3.5 wt% NaCl aqueous solution. This method is of great significance for promoting the application of magnesium alloys in industrial production.