Comprehensive model for the activation mechanism of Al-Zn alloys produced by indium
Exploratory work on the electrochemical behaviour of the Al-4%Zn alloy in the presence of In3+ in weakly acid chloride and acetic media is reported. It was found that in chloride solutions, active dissolution takes place at very negative potentials (-1.5 VSCE). This significative enhancement in the...
| Autores: | , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2005 |
| País: | Argentina |
| Institución: | Consejo Nacional de Investigaciones Científicas y Técnicas |
| Repositorio: | CONICET Digital (CONICET) |
| Idioma: | inglés |
| OAI Identifier: | oai:ri.conicet.gov.ar:11336/97849 |
| Acceso en línea: | http://hdl.handle.net/11336/97849 |
| Access Level: | acceso abierto |
| Palabra clave: | ACTIVATION MECHANISM ALUMINIUM ALLOY AMALGAM https://purl.org/becyt/ford/1.4 https://purl.org/becyt/ford/1 |
| Sumario: | Exploratory work on the electrochemical behaviour of the Al-4%Zn alloy in the presence of In3+ in weakly acid chloride and acetic media is reported. It was found that in chloride solutions, active dissolution takes place at very negative potentials (-1.5 VSCE). This significative enhancement in the electrochemical activity of the alloy is described and discussed. The aim of this paper is to explain the relationship between the operating potential (-1.1 VSCE) given by the commercial alloy (basically an Al-Zn-In alloy), its high efficiency, its quasi-uniform attack observed and the enhanced activity found (-1.5 VSCE). An unified model that explains this findings and the activation process of pure Al: by In3+ is proposed. It was found that two activation mechanism are operative on Al: (i) When sufficient amount of In at the interface in quasi-liquid state is present, an In-Al amalgam is responsible for the activation process (-1.5 VSCE). This process is favoured by Zn reach zones that favours In enrichment at the interface by displacement reaction, (ii) At higher anodic potentials (near -1.2 VSCE), the presence of In at the interface facilitates a chloride adsorption process which depolarised the anodic reaction. |
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