High corrosion-resistant octanoic acid vapor-phase modified Ce-LDH surface film of aluminum alloy

Abstract

The cerium salt modified LDH coating (Ce-LDH coating) was produced on AA5052 Al alloy surface by in-situ hydrothermal synthesis. The vapor phase assembly of octanoic acid (OA) was adopted to improve the further hydrophobicity of Ce-LDH layer. The octanoic acid modified Ce-LDH coating (VOA-Ce-LDH coating) was successfully prepared on AA5052 Al alloy. It indicates that the VOA-Ce-LDH coating has excellent anti-corrosion protection with a protection efficiency of 96.95%. VOA-Ce-LDH coating contains two different layers. The outer layer is an octanoic acid (OA) vapor phase assembly layer and a Zn-Al LDH layer. The inner layer is Al(OH)3 (aluminum hydroxide) layer. The physical barrier layer of OA and the corrosion ion trapping function of LDH give the good anti-corrosion protection of the modified coating. This study is helpful for the development of vapor phase corrosion inhibitors and LDH coating for corrosion protection on metal materials.