LDHs-APS/GO composite coating on AZ31B magnesium alloy for enhanced anti-corrosion property

The high active chemical properties of magnesium (Mg) alloys result in poor corrosion resistance, limiting their applications. Herein, a tri-layer composite coating with strong bonding force containing layered double hydroxide (LDH), 3-aminopropyltriethoxysilane (APS) and graphene oxide (GO) was fabricated onto the AZ31B Mg alloys surface by in-situ growth and self-assembly methods. The results showed that the corrosion resistance of Mg alloy was greatly improved after coated with the three-layer composite coating. Compared with Mg alloy, the corrosion current density of LDHs-APS/GO composite was reduced by 4 orders of magnitude. It was related to the synergistic effect of the strong binding force, the ion exchange capacity and the good barrier effect of the composite coating.