SiO2 based hybrid inorganic–organic films doped with TiO2–CeO2 nanoparticles for corrosion protection of AA2024 and Mg-AZ31B alloys

Hybrid sol–gel coatings provide an approach as protective layers on metals. In this work, corrosion protection of aluminium and magnesium alloys by SiO2-methacrylate coatings doped with TiO2–CeO2 nanoparticles was studied. The films show an improvement of the barrier properties at initial immersion. The reactivity of both alloys produces a deterioration of the protection with longer immersion, although TiO2–CeO2 nanoparticles let to observe signals of self-healing effect. Aluminium oxide/sol–gel interface was found to be stable. In combination with excellent paint adhesion on sol–gel films, these coatings can be a promising alternative pre-treatment for high strength aluminium alloys prior to painting.