Facile fabrication of a robust super-hydrophobic surface on magnesium alloy

A super-hydrophobic surface was successfully fabricated on magnesium alloy by electrodeposition of Zn–Co coating from choline chloride-based ionic liquid and subsequent surface modification. The water contact angle (CA) was measured to be as high as 152̊. Based on surface analysis by scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared (FTIR), the super-hydrophobicity can be attributed to both the rough and porous micro- and nano-scale binary structural Zn–Co coating and surface enrichment of low surface energy stearic acid (SA). The corrosion behavior was investigated with potentiodynamic polarization measurements and it was found that the super-hydrophobic coating considerably improved the corrosion resistant performance of magnesium alloy in 0.1 mol/L NaCl solution. In addition, the stability of the super-hydrophobic property was investigated by immersion in aqueous solution, finger touching and abrasion with sandpaper. The results showed that the super-hydrophobic coating exhibited high stability in aqueous solution, the rough surface textures were retained and the coating still exhibited a large contact angle after mechanical destroy.