Experiments on initiation of crevice corrosion were carried out on A1 specimens in dilute aqueous NaCI solutions at ambient temperature. Transient current distributions within crevices were measured by a sectioned electrode technique, and microsampling was used to monitor dissolved aluminum, pH, and [Cl−] composition changes within the crevice prior to breakdown. Auxiliary (noncrevice) experiments were carried out in solutions having various pH, [Cl−], and dissolved aluminum concentration. Initiation was found to occur upon exceeding a minimum concentration of dissolved aluminum inside the crevice. Mechanisms for initiation based on acidification within the crevice were excluded.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Renewable Energy, Sustainability and the Environment
- Surfaces, Coatings and Films
- Materials Chemistry