A comparison of corrosion inhibition of magnesium aluminum and zinc aluminum vanadate intercalated layered double hydroxides on magnesium alloys

The magnesium aluminum and zinc aluminum layered double hydroxides intercalated with NO ₃ ^- (MgAl-NO₃-LDH and ZnAl-NO₃-LDH) were prepared by the coprecipitation method, and the magnesium aluminum and the zinc aluminum layered double hydroxides intercalated with VO _x ^- (MgAl-VO _x -LDH and ZnAl-VO _x -LDH) were prepared by the anion-exchange method. Morphologies, microstructures and chemical compositions of LDHs were investigated by SEM, EDS, XRD, FTIR, Raman and TG analyses. The immersion tests were carried to determine the corrosion inhibition properties of MgAl-VO _x -LDH and ZnAl-VO _x -LDH on AZ31 Mg alloys. The results showed that ZnAl-VO _x -LDH possesses the best anion-exchange and inhibition abilities. The influence of treatment parameters on microstructures of LDHs were discussed. Additionally, an inhibition mechanism for ZnAl-VO _x -LDH on the AZ31 magnesium alloy was proposed and discussed.