Influence of Working Current Density on Formation and Corrosion Resistance of Super-Hydrophobic Coating on ZK60 Magnesium Alloy

To improve the corrosion resistance of magnesium alloys, super-hydrophobic (SH) coating was fabricated on the surface of ZK60 magnesium alloy coated with layered double hydroxides (LDHs) film. The electric field was introduced in the coating preparation process, and the influences of working current density on the characteristics of the coatings were researched. The results indicate that the working current densities significantly affect the microstructure of the LDHs films, which has an important impact on the hydrophobicity of the SH coatings. When the working current density is 25 mA/cm(2), the SH coating presents a homogenous micronano structure and super-hydrophobicity. The corrosion current density of the SH coating (I-corr =9x10(-7) A center dot cm(-2)) is two orders of magnitude lower than that of the ZK60 substrate (I-corr =3x10(-5) A center dot cm(-2)), indicating excellent corrosion resistance.

Automated summary

Super-hydrophobic coating was fabricated on the surface of ZK60 magnesium alloy coated with layered double hydroxides (LDHs) film to enhance the corrosion resistance of magnesium alloys. The working current density significantly affects the microstructure of the LDHs films, which in turn affects the hydrophobicity of the super-hydrophobic coatings. The optimized working current density of 25 mA/cm(2) resulted in a homogeneous micronano structure and excellent super-hydrophobicity of the coatings. Additionally, the corrosion current density of the super-hydrophobic coating was two orders of magnitude lower than that of the ZK60 substrate, demonstrating excellent corrosion resistance.