Corrosion protection of Nd–Fe–B type permanent magnets by zinc phosphate surface conversion coatings
| Autor: | N.M. Trepak, A. A. Lukin, L.A. Ilina, G. Pawłowska, S. Szymura, L.A. Isaicheva, Henryk Bala, V.A. Gaudyn |
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| Rok vydání: | 2001 |
| Předmět: |
Materials science
Mechanical Engineering Metallurgy Inorganic chemistry Metals and Alloys Zinc phosphate General Chemistry engineering.material equipment and supplies Phosphate Corrosion chemistry.chemical_compound chemistry Coating Mechanics of Materials Magnet Conversion coating Materials Chemistry engineering Polarization (electrochemistry) human activities Fluoride |
| Zdroj: | Intermetallics. 9:515-519 |
| ISSN: | 0966-9795 |
| DOI: | 10.1016/s0966-9795(01)00035-8 |
| Popis: | The use of protective zinc phosphate top coatings to protect Nd–Fe–B type permanent magnets against corrosion is discussed. The progress of the phosphatisation process has been tested by simultaneous measurement of pH near surface, corrosion potential, substrate mass loss and phosphate coating mass gain. The corrosion behaviour of the magnet in phosphate solution was analyzed by the anodic polarization technique and the general resistance of the magnet to corrosion was evaluated by the Akimov drop test. It is shown that immersion of the magnet in the acidified (pH=2) phosphating solution containing Zn(II), nitrate and fluoride ions resulted in the formation of well adhered, thin and tight hopeite layers, causing prolonged corrosion resistance of the magnet. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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