A comprehensive overview in improving corrosion resistance of Mg alloys: Enhancing protective coatings with plasma electrolytic oxidation and superhydrophobic coatings

• The combination of PEO and superhydrophobic coatings (SHC) holds promise for enhancing the corrosion resistance of Mg alloys. • After generating a rough surface using PEO, various methods are employed to graft long-chain molecules onto the surface, achieving superhydrophobicity. • Surface roughness and low surface energy play pivotal roles in creating SHC on Mg alloys. • The hierarchical microstructures of SHC trap an air layer, hindering the adhesion of aggressive ions and water molecules, thus impeding their penetration into the coating. • Despite progress, utilizing SHC for corrosion protection remains challenging. Purposeful fabrication and design are essential for practical SHC applications. The corrosion resistance of magnesium alloys is a significant concern in industries seeking to use these materials for lightweight structures. Plasma electrolytic oxidation (PEO) is a process that forms a ceramic oxide film on Mg alloy surfaces, effectively enhancing their corrosion performance in the short term. In this regard, optimizing PEO process parameters is crucial for creating a stable oxide layer. An improved level of corrosion resistance is ensured by applying superhydrophobic coating (SHC) on top of the PEO layer to prevent moisture infiltration, creating air pockets on the surface. Various methods are employed to fabricate SHC on Mg alloys, including techniques like electrophoretic deposition (EPD), Hydrothermal (HT), dip, and spray coating. The synergistic combination of PEO and SHC coatings has demonstrated encouraging outcomes in enhancing the corrosion performance of Mg alloys. This study offers an extensive overview of recent progress in the preparation, characterization, and corrosion behavior of Mg alloys by employing PEO coatings and SHC treatment processes.