A electro-deposition process for fabrication of biomimetic super-hydrophobic surface and its corrosion resistance on magnesium alloy

Super-hydrophobic surface has many special functions that are studied wildly. The ingenious microstructures of typical plant leaves with super-hydrophobicity enlighten researchers to design and fabricate artificial super-hydrophobic surface. Being the lightest alloy among structural metals materials magnesium alloy was restricted due to its poor corrosion resistance. A super-hydrophobic surface with self-cleaning was successfully deposited on AZ91D magnesium alloy by the nickel plating process. The super-hydrophobic surfaces were covered with cauliflower-like cluster binary micro-nano structural Ni coatings. The procedure was that the samples were processed by plating after pretreatment, finally modified by stearic acid (CH3(CH2)16COOH). The surface morphologies, chemical composition, wettability and corrosion resistance are characterized by means of SEM, FT-IR, water contact angle and electrochemical impedance spectroscopy (EIS) measurements. The as-prepared super-hydrophobic surface has a contact angle as high as 160.8 ± 1° and a SA as low as 1.8 ± 1°, showing good long-term stability. The super-hydrophobic surface exhibited excellent corrosion resistance property in the 3.5 wt. % NaCl solution. This method could provide a straightforward and effective route to fabricate large-area super-hydrophobic surface with anticorrosion and self-cleaning for a great number of potential applications, and easily extended to other metal materials.