Effect of different liquid–solid contact models on the corrosion resistance of superhydrophobic magnesium surfaces

• Superhydrophobic magnesium surfaces in Cassie–Baxter and Wenzel model were prepared.
• icorr in Cassie–Baxter model decreased four orders of magnitude than substrate.
• icorr in Wenzel model only decreased three orders of magnitude than substrate.
• Ratio of icorr between Wenzel and Cassie–Baxter model could be calculated.

Superhydrophobic surfaces contacting with liquid in Cassie–Baxter and Wenzel models were prepared on MgMnCe magnesium alloy by micro-arc oxidation (MAO), phytic acid etching and polymer plating. The corrosion current density of the films in Cassie–Baxter and Wenzel models decreased about four and three orders of magnitude, respectively, in comparison with the substrate. The ratio of corrosion current density of the film in Wenzel model to that in Cassie–Baxter model is approximately equal to the ratio of their actual contact area with liquid.