Abstract
No-rinse conversion coatings based on KMnO4, were applied to aluminium alloys and pure aluminium, and examined with X-ray absorption near edge spectroscopy (XANES). Some specimens were prepared beforehand and other specimens were freshly prepared immediately before testing, so that early changes in the coatings could be studied. A significant difference in composition was found between the one-week old specimens and the fresh. The old specimens consisted predominantly of Mn oxides, while the fresh specimens contained a substantial proportion of KMnO4. When fresh specimens were rinsed with de-ionised water, soluble KMnO4 was removed and the spectrum now showed evidence for mixed oxides, but no KMnO4, like the older specimens. Monitoring of specimens after exposure to 0.5% NaCl solution showed little further change in the film. (c) 2006 Elsevier Ltd. All rights reserved.
Original language | English |
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Pages (from-to) | 1981-1991 |
Number of pages | 11 |
Journal | Corrosion Science |
Volume | 49 |
Issue number | 4 |
DOIs | |
Publication status | Published - 1 Apr 2007 |
Keywords
- pitting corrosion, oxide coating
- XANES
- alummium, manganese