Advances in materials Research

  • 제4권4호
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  • Pages.227-233
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  • 2015
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  • 2234-0912(pISSN)
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  • 2234-179X(eISSN)
테크노프레스 (Techno-Press)
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DOI QR코드

DOI QR Code

Strategic coating of NdFeB magnets with Dy to improve the coercivity of permanent magnets

  • Ucar, Huseyin (Oak Ridge National Laboratory) ;
  • Parker, David S. (Oak Ridge National Laboratory) ;
  • Nlebedim, I.C. (Ames Laboratory) ;
  • McCallum, R.W. (Ames Laboratory) ;
  • McCall, S.K. (Lawrence Livermore National Laboratory) ;
  • Parans Paranthaman, M. (Oak Ridge National Laboratory)
  • 투고 : 2016.01.06
  • 심사 : 2016.03.31
  • 발행 : 2015.12.25
⟨ 이전 논문 다음 논문 ⟩

초록

We present a method, supported by theoretical analysis, for optimizing the usage of the critical rare earth element dysprosium in $Nd_2Fe_{14}B$ (NdFeB)-based permanent magnets. In this method, we use Dy selectively in locations such as magnet edges and faces, where demagnetization factors are largest, rather than uniformly throughout the bulk sample. A200 nm thick Dy film was sputtered onto a commercial N-38, NdFeB magnets with a thickness of 3 mm and post-annealed at temperatures from $600-700^{\circ}C$. Magnets displayed enhanced coercivities after post-annealing and as much as a 5 % increase in the energy product, while requiring a total Dy content of 0.06 wt. % - a small fraction of that used in the commercial grade Dy-NdFeB magnets. By assuming all Dy diffused into NdFeB magnets, the improvement in energy product corresponds to a saving of over 1% Dy (critical element). Magnets manufactured using this technique will therefore be higher performing which would potentially broaden the application space of these magnets in the traction motors of hybrid and pure electric vehicles, and wind generators.

키워드

참고문헌

  1. Bauder, D., Diamond, D., Li, J., McKittrick, M., Sandalow, D. and Telleen, P. (2011), "Critical materials strategy", U.S. Department of Energy,Washington.
  2. Boltich, E.B., Oswald, E., Huang, M.Q., Hirosawa, S., Wallace, W.E. and Burzo, E. (1985), "Magnetic characteristics of R2Fe14B systems prepared with high purity rare earths (R= Ce, Pr, Dy, and Er)", J. Appl. Phys., 57(8), 4106-4108. https://doi.org/10.1063/1.334633
  3. Buschow, K.J. (2005), Concise encyclopedia of magnetic and superconducting materials, Elsevier.
  4. Croat, J.J., Herbst, J.F., Lee, R.W. and Pinkerton, F.E. (1984), "High-energy product Nd-Fe-B permanent magnets", Appl. Phys. Lett., 44(1), 148-149. https://doi.org/10.1063/1.94584
  5. Doser, M. and Keeler, G. (1988), "Long‐term stability of Fe-B-Nd-Dy alloys made by Dy2O3 additions", J. Appl. Phys., 64(10), 5311-5313. https://doi.org/10.1063/1.342402
  6. Hirosawa, S., Matsuura, Y., Yamamoto, H., Fujimura, S., Sagawa, M. and Yamauchi, H. (1986), "Magnetization and magnetic anisotropy of R2Fe14B measured on single crystals", J. Appl. Phys., 59(3), 873-879. https://doi.org/10.1063/1.336611
  7. Kianvash, A., Mottram, R.S. and Harris, I.R. (1999), "Densification of a Nd 13 Fe 78 NbCoB 7-type sintered magnet by (Nd, Dy)-hydride additions using a powder blending technique", J. Alloy. Compd., 287(1), 206-214. https://doi.org/10.1016/S0925-8388(98)00874-3
  8. Komuro, M., Satsu, Y. and Suzuki, H. (2010), "Increase of coercivity and composition distribution in fluoride-diffused NdFeB sintered magnets treated by fluoride solutions", Proceedings of the IEEE Transactions on Magnetics, 46(11), 3831-3833.
  9. Kronmuller, H., Durst, K.D. and Martinek, G. (1987), "Angular-dependence of the coercive field in sintered Fe77Nd15B8 magnets", J. Magn. Magn. Mater., 69(2), 149-157. https://doi.org/10.1016/0304-8853(87)90111-9
  10. Nakamura, H., Hirota, K., Ohashi, T. and Minowa, T. (2011), "Coercivity distributions in Nd-Fe-B sintered magnets produced by the grain boundary diffusion process", J. Phys. D: Appl. Phys., 44(6), 064003. https://doi.org/10.1088/0022-3727/44/6/064003
  11. Sagawa, M., Fujimura, S., Yamamoto, H., Matsuura, Y. and Hiraga, K. (1984), "Permanent magnet materials based on the rare earth-iron-boron tetragonal compounds", Proceedings of the IEEE Trans. Magn., 20(5), 1584-1589.
  12. Smith, A., Nielsen, K.K., Christensen, D.V., Bahl, C.R.H., Bjork, R. and Hattel, J. (2010), "The demagnetizing field of a nonuniform rectangular prism", J. Appl. Phys., 107(10), 103910. https://doi.org/10.1063/1.3385387
  13. Soderznik, M., Rozman, K.Z., Kobe, S. and McGuiness, P. (2012), "The grain-boundary diffusion process in Nd-Fe-B sintered magnets based on the electrophoretic deposition of $DyF_3$", Intermetallics, 23, 158-162. https://doi.org/10.1016/j.intermet.2011.11.014
  14. Sugimoto, S. (2011), "Current status and recent topics of rare-earth permanent magnets", J. Phys. D: Appl. Phys., 44(6), 064001. https://doi.org/10.1088/0022-3727/44/6/064001
  15. Tang, W., Dennis, K.W., Kramer, M.J., Anderson, I.E. and McCallum, R.W. (2012), "Studies of sintered MRE-Fe-B magnets by $DyF_3$ addition or diffusion treatment (MRE = Nd+Y+Dy)", J. Appl. Phys., 111(7), 07A736. https://doi.org/10.1063/1.3679465
  16. Tenaud, P., Lemaire, H. and Vial, F. (1991), "Recent improvements in NdFeB sintered magnets", J. Magn. Magn. Mater., 101(1), 328-332. https://doi.org/10.1016/0304-8853(91)90767-5
  17. Xu, F., Zhang, L., Dong, X., Liu, Q. and Komuro, M. (2011), "Effect of $DyF_3$ additions on the coercivity and grain boundary structure in sintered Nd-Fe-B magnets", Scripta Mater., 64(12), 1137-1140. https://doi.org/10.1016/j.scriptamat.2011.03.011

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