A novel bilayer system comprising LDH conversion layer and sol-gel coating for active corrosion protection of AA2024

Abstract

In this work active corrosion protection of AA2024 by a bilayer system consisting of a LDH (layered double hydroxides) conversion layer coated by a sol-gel film was studied. Impedance and Scanning vibrating electrode technique (SVET) studies demonstrated an efficient active corrosion protection and self-healing abilities of the systems containing LDH layer loaded with vanadate corrosion inhibitor. Microstructural and chemical analysis of the surface after corrosion testing showed accumulation of chlorine signal in LDH coatings. The scavenging of chlorides and release of vanadate inhibitor from LDH can explain high efficiency of corrosion inhibition of AA2024 by the novel protective system.