We’ve investigated the effect of preliminary Al substrate treatment on the deposition and corrosionprotection ability of thin, conversion cerium oxide layers formed in solutions containing Ce3+ and Cu2+ions. The cerium oxide layers and their corrosion protection behaviour were investigated by SEM,EDS, XPS, and model polarization E-lg i and I-t chronoamperometric curves. We report on thestructure, morphology, chemical composition and the state of the elements in the conversion layers, aswell as the thickness and distribution of the elements up to the ?conversion layer”/”aluminiumsubstrate” interphase boundary. The preliminary treatment of the Al substrate, as well as the presenceof Cu2+, both substantially influence the thickness, composition and protective ability of the formedceria and alumina mixed conversion layers. All these features are related to changes in the ratio of theformed AlOOH (~Al2O3.H2O), Ce(OH)3 (~Ce2O3) and Ce(OH)4 (~CeO2) on the modified Al surface,which are affected by the preliminary treatment of the Al substrate and presence of Cu2+ ions in theimmersion treatment solution based on Ce3+ ions.
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