Superhydrophobic Silane/Fluorinated Attapulgite@SiO2 Composite Coatings on Magnesium Alloy for Corrosion Protection

Abstract To improve the corrosion resistance of magnesium alloys, superhydrophobic coatings were prepared by employing fluorinated attapulgite@SiO 2 (F‐ATP@SiO 2 ) particles and silanes via a facile one‐step spraying technique in this study. Surface morphology, chemical compositions, roughness and wettability of the coatings were comprehensively investigated by Field emission scanning electron microscopy (FESEM), Fourier transform infrared spectra (FTIR), 3D optical microscope and contact angle techniques, respectively. Corrosion resistance of the coatings was evaluated by potentiodynamic polarization test and electrochemical impedance spectroscopy (EIS). Results indicated that the coatings exhibited superhydrophobicity due to its micron scale mastoid structure and low surface energy of F‐ATP@SiO 2 particles. The superhydrophobicity and anticorrosion performance of the coatings increased with the dosage increase of F‐ATP@SiO 2 particles. The water contact angle of the prepared surface can reach as high as 161° with sliding angle of 4°. I corr of the coatings can reach 5.519×10 −8 A cm −2 , decreased by 3 orders of magnitude compared to bare AZ31, which showed excellent anticorrosion performance. With the prolongation of immersion time, the EIS analysis indicated that the anticorrosion property of the coating degraded gradually. Based on the electrochemical analysis, the corrosion protection mechanism of the superhydrophobic coating was proposed.