Dual self-healing effects of salicylate intercalated MgAlY-LDHs film in-situ grown on the micro-arc oxidation coating on AZ31 alloys

Abstract

Micro-arc oxidation (MAO) coatings only provide the passive protection of common Mg alloys (AZ31), especially causing severe localized corrosion under accidental damage. Herein, a novel MgAlY-Layered double hydroxides (LDHs) film loaded with salicylate is successfully prepared on flash-MAO coated AZ31 alloys, by the one-step hydrothermal and intercalation methods. The in-situ grown LDHs platelets seal the porous morphology, significantly improving the corrosion performance. Moreover, self-healing measurements (SVET) and characterizations (EDS, XRD, and FT-IR) demonstrate that the endowed active corrosion protection is attributed to the corrosion inhibition of anion-exchange reaction, and dual self-healing effects of yttrium oxide and Y(III) - salicylate complexes.