Enhanced super-hydrophobicity and corrosion resistance of the one-step hydrothermal synthesized coating on the Mg-9Li alloy: Role of the solid-solution treated substrate

Formation of super-hydrophobic coating on the surface is an effective way to solve the corrosion challenge of magnesium alloys, while the microstructure and performance of the coating are greatly affected by the microstructure characteristic of the substrate alloy. Herein, the enhanced super-hydrophobic and anti-corrosion performance of a coating is achieved on the solid-solution (ss) treated Mg-9Li alloy by hydrothermal method. The obtained coating with a contact angle of 154 ° presents excellent hydrophobicity owing to the micro-nano rough structures and low surface energy. The ss treatment strengthens the anti-corrosion performance of the substrate, and provides more nucleation sites and intensive driving force for hydrothermal reaction to favor a denser and thicker coating than that of the cast alloy substrate, which effectively retards the corrosion damage. This study provides a new strategy for the corrosion protection of magnesium-lithium alloys.