Effect of Corrosion Inhibitor Pyrovanadate Ions on Microstructure and Corrosion Resistance of MgAl Layered Double Hydroxide Films on LA43M Mg-Li Alloy

In order to explore the effect of corrosion inhibitor modification on the microstructure and corrosion resistance of MgAl layered double hydroxide (LDH) film on LA43M Mg-Li alloy, the LDH films were successfully obtained by ion exchange method at different hydrothermal temperatures. Microstructure of the MgAl LDH films with anion intercalation were characterized by SEM, EDS and XRD, and the corrosion resistance of the films were tested by EIS, polarization curve and hydrogen evolution experiments. The results showed that the modified LDH nanosheets are larger in size, denser and slightly thicker than that of MgAl LDH film. Electrochemical tests and hydrogen precipitation experiments demonstrated that the corrosion inhibitor modified LDH films can further enhance the corrosion resistance of the film. The LDH prepared at 60°C has the most uniform density and the maximum thickness. It has the lowest Icorr(1.754×10−8 A.cm2) and the most positive Ecorr(−1.147 V). Furthermore, it showed the best corrosion resistance in 3.5 wt% NaCl solution.