Fabrication and Corrosion Resistance of Molybdate Intercalated Layered Double Hydroxide Coatings with Superhydrophobic Surface

MgAl-LDH-MoO₄^2- layered double hydroxide (LDH) coating was deposited on AZ31B magnesium alloy by coprecipitation and hydrothermal method. X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform-infrared spectoscopy (FT-IR) were used to characterize the morphology of the coating. Electrochemical methods were used to analyze the corrosion behavior of specimens immersed in 3.5% (mass fraction) NaCl solution for several days. The results showed that MgAl-LDH-MoO₄^2- coating grew uniformly and continuously on the surface of AZ31B magnesium alloy. The molybdate ion as corrosion inhibitor was successfully inserted into the interlayer and released in corrosive chloride ion environment with good corrosion inhibition performance and ion exchange performance. In addition, hydrophobic modification of the surface of hydrotalcite coating with FDTS (1H, 1H, 2H, 2H-Per fluorodecyltriethoxysilane) further extended the life time of the hydrotalcite coating.