Fabrication of fibrous szaibelyite with hierarchical structure superhydrophobic coating on AZ31 magnesium alloy for corrosion protection

•Fibrous szaibelyite films were prepared on magnesium alloy AZ31.•The growth solution does not contain any template and surfactant.•After modified with FAS, the film shows superior superhydrophobic property.•Superhydrophobic film significantly improved the anticorrosion property of Mg alloy.

Hierarchical structure fibrous szaibelyite films were fabricated by a simple template-free hydrothermal synthesis method on AZ31 magnesium alloy. After modification with fluoroalkylsilane (FAS), the films exhibited advantageous superhydrophobic properties with a static water contact angle of 166° and a sliding angle less than 5°. From the results of X-ray diffraction (XRD), transmission electron microscope (TEM) and scanning electron microscopy (SEM), a possible mechanism for formation of the hierarchical structure of the fibrous szaibelyite films was discussed. In addition, corrosion resistance performance of the superhydrophobic surface was investigated by electrochemical potentiodynamic measurements and electrochemical impedance spectroscopy. The superhydrophobic film maintained excellent corrosion resistance performance, after immersion in a corrosive medium (3.5 wt.% NaCl aqueous) for 32 days. We concluded that the superhydrophobic film provided an effective anticorrosion coating for AZ31 magnesium alloy.

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