Magnetic Behavior of Sintered NdFeB Magnets on a Long-Term Timescale
Stable polarization of permanent magnets over the lifetime of the application is an important aspect in electrical machine design. Specification of the long-term stability of magnet material is difficult, since knowledge of the phenomenon is incomplete. To be able to optimize magnet material selecti...
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| Format: | Article |
| Language: | English |
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Wiley
2014-01-01
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| Series: | Advances in Materials Science and Engineering |
| Online Access: | http://dx.doi.org/10.1155/2014/760584 |
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| author | Minna Haavisto Sampo Tuominen Timo Santa-Nokki Harri Kankaanpää Martti Paju Pekka Ruuskanen |
| author_facet | Minna Haavisto Sampo Tuominen Timo Santa-Nokki Harri Kankaanpää Martti Paju Pekka Ruuskanen |
| author_sort | Minna Haavisto |
| collection | DOAJ |
| description | Stable polarization of permanent magnets over the lifetime of the application is an important aspect in electrical machine design. Specification of the long-term stability of magnet material is difficult, since knowledge of the phenomenon is incomplete. To be able to optimize magnet material selection, the long-term magnetic behavior of the material must also be understood. This study shows that material with a very square JH curve is stable until a certain critical operating temperature is reached. Major losses are detected as the critical temperature is exceeded. Material with a rounder JH curve does not show a well-defined critical temperature, but increasing losses over a large temperature range. The critical temperature of a material is also dependent on the field conditions. Results differ whether the tests are performed in an open or closed magnetic circuit. In open-circuit tests, the opposing field is not homogeneously distributed throughout the volume of the magnet and thus the long-term behavior is different than that in closed-circuit conditions. Open-circuit tests seem to give bigger losses than closed-circuit tests in cases where the permeance coefficient of the open-circuit sample is considered to be the average permeance coefficient, calculated according to the dimensions of the magnet. |
| format | Article |
| id | doaj-art-65819fd8f57141f2891903aebca100e2 |
| institution | Kabale University |
| issn | 1687-8434 1687-8442 |
| language | English |
| publishDate | 2014-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | Advances in Materials Science and Engineering |
| spelling | doaj-art-65819fd8f57141f2891903aebca100e22025-02-03T01:13:09ZengWileyAdvances in Materials Science and Engineering1687-84341687-84422014-01-01201410.1155/2014/760584760584Magnetic Behavior of Sintered NdFeB Magnets on a Long-Term TimescaleMinna Haavisto0Sampo Tuominen1Timo Santa-Nokki2Harri Kankaanpää3Martti Paju4Pekka Ruuskanen5Prizztech Oy, Magnet Technology Centre, 28100 Pori, FinlandPrizztech Oy, Magnet Technology Centre, 28100 Pori, FinlandPrizztech Oy, Magnet Technology Centre, 28100 Pori, FinlandNeorem Magnets Oy, 28400 Ulvila, FinlandPrizztech Oy, Magnet Technology Centre, 28100 Pori, FinlandTampere University of Technology, 28100 Pori, FinlandStable polarization of permanent magnets over the lifetime of the application is an important aspect in electrical machine design. Specification of the long-term stability of magnet material is difficult, since knowledge of the phenomenon is incomplete. To be able to optimize magnet material selection, the long-term magnetic behavior of the material must also be understood. This study shows that material with a very square JH curve is stable until a certain critical operating temperature is reached. Major losses are detected as the critical temperature is exceeded. Material with a rounder JH curve does not show a well-defined critical temperature, but increasing losses over a large temperature range. The critical temperature of a material is also dependent on the field conditions. Results differ whether the tests are performed in an open or closed magnetic circuit. In open-circuit tests, the opposing field is not homogeneously distributed throughout the volume of the magnet and thus the long-term behavior is different than that in closed-circuit conditions. Open-circuit tests seem to give bigger losses than closed-circuit tests in cases where the permeance coefficient of the open-circuit sample is considered to be the average permeance coefficient, calculated according to the dimensions of the magnet.http://dx.doi.org/10.1155/2014/760584 |
| spellingShingle | Minna Haavisto Sampo Tuominen Timo Santa-Nokki Harri Kankaanpää Martti Paju Pekka Ruuskanen Magnetic Behavior of Sintered NdFeB Magnets on a Long-Term Timescale Advances in Materials Science and Engineering |
| title | Magnetic Behavior of Sintered NdFeB Magnets on a Long-Term Timescale |
| title_full | Magnetic Behavior of Sintered NdFeB Magnets on a Long-Term Timescale |
| title_fullStr | Magnetic Behavior of Sintered NdFeB Magnets on a Long-Term Timescale |
| title_full_unstemmed | Magnetic Behavior of Sintered NdFeB Magnets on a Long-Term Timescale |
| title_short | Magnetic Behavior of Sintered NdFeB Magnets on a Long-Term Timescale |
| title_sort | magnetic behavior of sintered ndfeb magnets on a long term timescale |
| url | http://dx.doi.org/10.1155/2014/760584 |
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