C. Liu and G.T. Burstein (Department of MateriaIs Science and Metallurgy
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University of Cambridge
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Pembroke Street
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Cambridge CB2 3QZ
,
United Kingdom)
金属学报(英文版)
The passivity of guillotined aluminium electrode is enhanced in alkaline electrolytes by SiO32-. It is proposed that the formation of a complete aluminosilicate gel is responsible for this phenomenon. Dissolution of the metal proceeds via the existing film and the dissolution product reacts with SiO_3~2- ions to form the gel. Under galvanostatic polarisation, significant amount of the gel is formed when the applied anodic i > 10mA cm-2. This gel layer can then be transformed into barrier-type of oxide film, thus contributing to the initial stage of the high voltage anodisation.
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passivity
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