The study on corrosion resistance of superhydrophobic magnesium hydroxide coating on AZ31B magnesium alloy

摘要

Superhydrophobic technology is very practical for anti-corrosion, anti-rust, and anti-fouling in the construction industry, automobile industry and metal industry. Herein, a facile approach was developed to fabricate superhydrophobic and anti-corrosive (SAC) coatings on the surface of magnesium alloy. The magnesium alloy was hydrothermally treated to form a layer of magnesium hydroxide, on which stearic acid (STA) were grafted. The micro-nano structure fabricated by intersected lamellar magnesium hydroxide and low surface energy provided by STA created a superhydrophobic surface with a water contact angle (WCA) of 159 degrees, improving the corrosion resistance of magnesium alloy. The self-growing superhydrophobic coating is of strong adhesion. With the X-cut on the surface of magnesium alloy, the corrosion appeared just along the X-cut without any spread even after 10 day immersion in 3.5 wt.% NaCl aqueous solution, indicating good corrosion resistance and durability. This approach for fabricating SAC magnesium alloys is simple, cost-effective and eco-friendly, demonstrating significant advantages in practical application.