Inhibiting effect of 8-hydroxyquinoline on the corrosion of silane-based sol-gel coatings on AA 2024-T3

This work presents the silane-based sol-gel coatings that prepared by in situ doping 8-hydroxyquinoline as corrosion inhibitor for the protection of AA 2024-T3. The morphology and thickness of the sol-gel coatings were observed by scanning electron microscope (SEM). Immersion tests and electrochemical impedance spectroscopy (EIS) were used to study the corrosion resistance of the blank and 8-hydroxyquinoline doped sol-gel coatings. The results indicate that the addition of 8-hydroxyquinoline effectively improved the corrosion resistance of the sol-gel coatings. The self-healing effect of 8-hydroxyquinoline on the corrosion in the defects of sol-gel coating was assessed by scanning vibrating electrode technique (SVET) and proved by the results of energy-dispersive X-ray spectroscopy (EDS) mapping.