| Numéro |
J. Phys. IV France
Volume 7, Numéro C2, Avril 1997
Proceedings of the 9th International Conference on X-Ray Absorption Fine Structure
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|---|---|---|
| Page(s) | C2-1183 - C2-1184 | |
| DOI | https://doi.org/10.1051/jp4:19972184 | |
Proceedings of the 9th International Conference on X-Ray Absorption Fine Structure
J. Phys. IV France 7 (1997) C2-1183-C2-1184
DOI: 10.1051/jp4:19972184
1 Corrosion and Protection Center, UMIST, Manchester M60 1QD, UK
2 Institute of Physics, Chinese Academy of Sciences, Beijing, 100080, China
3 Defence Research Agency, Farnborough, Hants, GU14 6TD, UK
© EDP Sciences 1997
J. Phys. IV France 7 (1997) C2-1183-C2-1184
DOI: 10.1051/jp4:19972184
XANES Study of Ce and Mo Containing Conversion Coatings on Aluminium
J. Wan1, G.E. Thompson1, T.K. Ng1, K.Q. Lu2 and C.J.E. Smith31 Corrosion and Protection Center, UMIST, Manchester M60 1QD, UK
2 Institute of Physics, Chinese Academy of Sciences, Beijing, 100080, China
3 Defence Research Agency, Farnborough, Hants, GU14 6TD, UK
Abstract
Ce-Mo conversion coatings on superpure aluminium have been examined using XANES and analytical TEM to study the coating development over the electropolished surface. Ce species are predominantly in the Ce3+ state in the coating, resulting from the various steps of the process, and Mo is in the Mo6+ state. After immersion in NaCl solution, Ce and Mo species leach from the coating. Conversion coating formation develops a hydrated film with cerium species incorporated ; final anodic polarisation in MoO42- solution results in Mo species in the hydrated film. Corrosion inhibition is attributed to the coating acting as a barrier layer to environmental access to the aluminium substrate and reduced cathodic activity.
© EDP Sciences 1997