Effect of divalent metal ions on durability and anticorrosion performance of layered double hydroxides on anodized 2A12 aluminum alloy

Inhibitor-loaded layered double hydroxides (LDHs) sealing layers were prepared by hydrothermal co-precipitation method for anodic aluminum oxide (AAO) film on 2A12 aluminum alloy. Effects of different divalent metal ions (M2+ = Ni2+, Zn2+) on the LDHs structure and the anticorrosion behaviors of the corresponding sealing layer were investigated. Compared with the Zn-based LDHs, the Ni-based LDHs possesses a smaller basal spacing and a stronger interlayer interaction. The results revealed that the compact Ni-based sealing LDHs layer loaded with a large number of vanadate corrosion inhibitors exhibited high durability and excellent corrosion protection for an exposure time of 14 days in 3.5% NaCl solution. This study provides significant insights into understanding the anticorrosion effect of different divalent metal ions on the structure of the LDHs sealing layer.