Competitive effects of metal dissolution and passivation modulated by surface structure: An AFM and EBSD study of the corrosion of alloy 22
| Autor: | B.S. El Dasher, Christine A. Orme, J. J. Gray |
|---|---|
| Rok vydání: | 2006 |
| Předmět: |
Materials science
Passivation Alloy Oxide Analytical chemistry Surfaces and Interfaces engineering.material Condensed Matter Physics Surfaces Coatings and Films Corrosion Dielectric spectroscopy chemistry.chemical_compound Crystallography chemistry Electron diffraction Materials Chemistry engineering Dissolution Electron backscatter diffraction |
| Zdroj: | Surface Science. 600:2488-2494 |
| ISSN: | 0039-6028 |
| DOI: | 10.1016/j.susc.2006.04.002 |
| Popis: | Electron backscatter diffraction (EBSD) and atomic force microscopy (AFM) are used to correlate crystallographic grain orientation with corrosion rates of polycrystalline alloy 22 following immersion in 1 and 3 molar (M) hydrochloric acid. For each acid concentration, relative corrosion rates are simultaneously characterized for approximately 50 unique grain orientations. The results demonstrate that the corrosion rate anisotropies are markedly different in the two acid concentrations. In very aggressive acidic environments (3M HCl), where electrochemical impedance spectroscopy and spectroscopic ellipsometry data demonstrate that the passive oxide film of alloy 22 is completely dissolved, alloy dissolution rates scale inversely with the average coordination number of surface atoms for a given grain orientation, where highly correlated surfaces dissolve the slowest. Thus, similar to simple metallic systems, the corrosion rates scale with the surface plane-normal crystallographic orientations as {1 1 1} |
| Databáze: | OpenAIRE |
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