Sol–gel coatings modified with zeolite fillers for active corrosion protection of AA2024

[Display omitted] ► Zeolites as nanocontainers for corrosion inhibitors. ► Ce (III) as corrosion inhibitor. ► pH as the trigger mechanism of cerium release from zeolites. ► Zeolites improved the barrier properties of the hybrid sol–gel films. ► Ce (III) releases from Ce–zeolite and precipitates on intermetallic inclusions. This work presents a new approach to develop active protection coating systems. Zeolite microparticles were used as reservoirs for Ce (III). The zeolites were introduced into silica–zirconia sol–gel films, improving the barrier properties of the coating and conferring active corrosion protection to the AA2024 substrate. The corrosion process changes the pH of solution locally causing release of inhibitor that precipitates in the cathodic areas. Intermetallic inclusions seem to be sites prone to the formation of these cerium rich precipitates. The protection properties of the modified coatings were assessed using EIS.