Electrical and magnetic properties of hot-deformed Nd-Fe-B magnets with different DyF3 additions
2013; American Institute of Physics; Volume: 114; Issue: 13 Linguagem: Inglês
10.1063/1.4822026
ISSN1520-8850
AutoresSimon Sawatzki, Imants Dirba, L. Schultz, Oliver Gutfleisch,
Tópico(s)Magnetic properties of thin films
ResumoThe effect of deformation and DyF3 additions on the electrical resistivity and the magnetic performance has been studied in hot-deformed Nd-Fe-B melt-spun ribbons and correlated with respective microstructures. Despite the nanocrystallinity of hot-compacted magnets, the specific electrical resistivity measured by four-point-method was shown to be comparable with that of sintered magnets. Die-upsetting reduces electrical resistivity within the magnetically hard plane because of an enhanced shape anisotropy of the grains. The addition of DyF3 overcompensates this reduction due to the presence of electrically insulating Dy-F rich inclusions and thus reduces eddy current losses within the magnet. Magnetic measurements reveal an increase in coercivity without a change in remanence for die-upset magnets with a total height reduction of 63% and 1.2 wt. % Dy (1.6 wt. %DyF3). Both properties, remanence and coercivity, demonstrate an effective reduction in heavy rare earth Dy for Nd-Fe-B magnets.
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