Enhancing the anticorrosion properties of nanoporous anodic oxide film by sealing process
Valentin-Marian DUMITRASCU, Lidia BENEA
Competences Center: Interfaces-Tribocorrosion-
Because of its properties: lightweight, strength and corrosion resistance, aluminum and its alloys are chosen for building various industrial equipments that are used in different specific environments. Aluminum and its alloys can not escape from corrosion and its need a proper handling. Aluminum and its alloys will corrode very quickly after cleaning so any treatment must be swift to prevent corrosion becoming trapped under the base coating layers.
Aluminum corrodes almost immediately forming an oxide layer that will protect it from further corrosion.
Anodic oxidation it is the easiest way to protect aluminum against corrosion, by producing on its surface a thick nanoporous aluminum oxide layer.
The aim of this research work was to obtain a nanoporous oxide layer on aluminum substrate and to increase the anticorrosion resistance by sealing the nanopores. After the anodic formation of alumina film and the sealing procedure, the anticorrosion performances of the films were evaluated by electrochemical methods such as open circuit potential, potentiodynamic polarization and cyclic voltammetry. The results were compared with those obtained for unsealed anodized film. The results showed an increase of corrosion resistance for sealed anodized layers.
Aluminum anodic oxidation, sealing procedure, corrosion behavior, electrochemical impedance spectroscopy