Resumo

VASQUEZ RENDON, Mauricio; FERNANDEZ, Patricia  e  CALDERON, Jorge Andrés. Electrochemical characterization of aluminum A-356 metallic foams obtained from soluble perform infiltration. Rev. ion [online]. 2012, vol.25, n.spe, pp.17-22. ISSN 0120-100X.

This study evaluates the electrochemical behavior of aluminum metal foams using electrochemical techniques such as polarization curves and electrochemical impedance spectroscopy. Tests were performed in solutions of NaCl under hydrodynamic conditions. The polarization curves show that the overall process is controlled by the cathodic branch, where there is a clear dependence on transport of oxygen to the surface of metal. Furthermore, at low rotation rates the cathodic behavior of the metal foams is similar to a solid electrode, following a linear relationship between the current and the square root of the rotation rate. At high speeds it was found that the cathodic limiting current is much greater than for a solid electrode, and the relationship of the current limit with the square root of the rotation rate has a sigmoidal behavior. Electrochemical impedance curves show a linear behavior at very high frequencies followed by a capacitive loop at intermediate frequencies, this behavior is related to the charge transfer processes in a porous electrode. Additionally impedance diagrams show an inductive loop at low frequencies related to metal dissolution process.

Palavras-chave : corrosion; cellular metals; electrochemical techniques.

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