Advances in micro-arc oxidation coatings on Mg-Li alloys

Magnesium-lithium (Mg-Li) alloys have become promising metal engineering materials due to the outstanding weight reduction performance. However, the vulnerability to corrosion is a major obstacle for development. A variety of surface treatment methods have been applied to protect Mg-Li alloys against corrosion deterioration, among which micro-arc oxidation (MAO) is an effective and economic method. Additionally, MAO coatings also present high hardness, excellent wear resistance, and strong bonding to the substrate. This article reviews advances in MAO coatings on Mg-Li alloys, which includes summarizations for the MAO parameters and factors affecting the properties of the coatings. The main focus is given to characteristics of the MAO coatings on Mg-Li alloys, as well as the functionalization performance in a wide application.