Corrosion resistance of aluminum alloys

This diploma thesis deals with cerium-based conversion coatings for aluminium alloys. At first the mechanism of protection of metals by inhibitory substances is described in the theoretical section. The next chapter is devoted to application of lanthanide salts as cathodic corrosion inhibitors. Then the characterization of alloy AA 2024 follows. The main part is dedicated to the growth mechanism of the cerium-based mixed conversion coating on the alloy AA 2024. Finally, the factors affecting the character and the quality of obtained coatings are commented. In the experimental part an influence of the thermal activation together with the activation by a hydrogen peroxide was observed. The created film was characterized using SEM and EDS. The level of corrosion protection was evaluated by the polarization resistance measurement. erized using SEM and EDS. The level of corrosion protection was evaluated by the polarization resistance measurement