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Galvanic Coupling Between Pure Copper and Pure Aluminum Experimental Approach and Mathematical Model

Jorcin, Jean-Baptiste and Blanc, Christine and Pébère, Nadine and Tribollet, Bernard and Vivier, Vincent Galvanic Coupling Between Pure Copper and Pure Aluminum Experimental Approach and Mathematical Model. (2008) Journal of The Electrochemical Society (JES), 155 (1). C46-C51. ISSN 0013-4651

(Document in English)

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Official URL: http://dx.doi.org/10.1149/1.2803506


The corrosion behavior of a pure aluminum/pure copper couple in a weakly conductive sulfate solution was investigated. Potential and current distributions on the surface of the model couple at the beginning of immersion were obtained by solving the Laplace equation using a finite element method (FEM) algorithm. The potential distribution predicted by the calculations was checked using a Ag/AgCl microreference electrode. A good agreement was found between experimental and theoretical results. It was shown that the reaction occurring at the copper electrode was oxygen reduction, while aluminum remote from the Al/Cu interface remained in the passive state. Moreover, calculations predicted a large cathodic current, related to an increase in oxygen reduction, restricted to copper at the Al/Cu interface. This led to a local pH increase reaching values higher than 9, allowing the dissolution of aluminum to occur close to the interface. Combining these data with optical and scanning electron microscope observations after 24 h of immersion in the sodium sulfate solution allowed a three-step mechanism to be proposed to explain the corrosion damage, and particularly the presence of a copper deposit on the aluminum surface, some distance from the Al/Cu interface, a phenomenon currently observed in commercial copper-rich aluminum alloys.

Item Type:Article
Additional Information:Thanks to Electrochemical Society editor. The definitive version is available at http://scitation.aip.org The original PDF of the article can be found at Journal of The Electrochemical Society website : http://www.ecsdl.org/JES/
HAL Id:hal-00806027
Audience (journal):International peer-reviewed journal
Uncontrolled Keywords:
Institution:Université de Toulouse > Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE)
Other partners > Université Pierre et Marie Curie, Paris 6 - UPMC (FRANCE)
Université de Toulouse > Université Toulouse III - Paul Sabatier - UT3 (FRANCE)
French research institutions > Centre National de la Recherche Scientifique - CNRS (FRANCE)
Laboratory name:
Deposited On:29 Apr 2009 14:43

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