Sealing of tartaric sulfuric (TSA) anodized AA2024 with nanostructured LDH layers
By Kuznetsov, B. and Serdechnova, M. and Tedim, J. and Starykevich, M. and Kallip, S. and Oliveira, M. P. and Hack, T. and Nixon, S. and Ferreira, M. G. S. and Zheludkevich, M. L.
Published in RSC Adv.
The Royal Society of Chemistry
2016
Abstract
In this work, a functional sealing of a TSA anodic layer on AA2024 is suggested based upon the formation of inhibitor-containing Zn-Al layered double hydroxides (LDH). The LDH structures are formed in the pores of the anodic layer and on top of it as a result of hydrothermal treatment in a Zn2+-containing bath as shown by the structure, morphology and composition analysis. The resulting LDHs were loaded with a well-known corrosion inhibitor (vanadate). Electrochemical impedance spectroscopy, salt spray tests and scanning vibrating electrode techniques have shown a remarkable improvement in corrosion resistance of the LDH-modified sample in comparison with conventional hot-water sealing. The vanadate-loaded LDHs rendered a significant long-term active protection for the covered aluminum alloy substrate.