Preparation of Al Coating on Mg-Li Alloy with Molten Salt Replacement

A method of molten salt replacement was used to prepare an Al coating on Mg-Li alloy at different temperatures. The thickness, microstructure, phase composition and corrosion electrochemical analysis of the coating treated at different temperatures were analyzed. The corrosion resistances of the specimens with and without optimal coating were comparatively evaluated. Results show that, the optimal treatment temperature is 350 °C, at which a thickness of 9.15 μm coating is formed. In the Al coatings, Al exists as the form of Mg17Al12 and AlLi. The corrosion resistance is much better than that of the specimen without coating.