Fabrication of Superhydrophobic Zn-Ni Coatings on LA43M Magnesium Alloy

The superhydrophobic Zn-Ni coatings with porous microstructures were prepared on LA43M Mg alloys substrate by dynamic hydrogen bubble template method. The effects of Ce-2(SO4)(3) concentrations on the coating structure and wettability were studied. It was found that the contact angle of superhydrophobic coatings could be up to 157.4 +/- 0.7 degrees by changing concentrations of cerium sulfate in baths. XRD revealed that the coatings with porous microstructures mainly consisted of gamma-Ni5Zn21, delta-Ni3Zn22, and CeNi5. Polarization measurements demonstrated that corrosion current density value of 6.0 x 10(-7) A cm(-2) of the coating was lower than that of the substrate, which means that the coatings are effective to improve the anti-corrosion performance of LA43M magnesium alloys. EIS showed that the coating served as a barrier to resist charge transfer. The study provides a new means to develop coatings with superhydrophobic performance on the LA43M magnesium alloys surface, which is in favor of the application of Mg alloys.