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2019 | OriginalPaper | Chapter

Nd–Fe–B-Based Sintered Magnet

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Author: Takeshi Nishiuchi

Publisher: Springer Singapore

Published in: Magnetic Material for Motor Drive Systems

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Abstract

Sintered magnets based on neodymium (Nd), iron (Fe) and boron (B) were invented in 1982. They exhibit the highest performance among the industrially manufactured magnets. Nd–Fe–B magnets not only show excellent magnetic properties but are suitable for mass production as well. Therefore, they are used for many applications, especially for high-performance motors. This chapter offers basic knowledge for understanding Nd–Fe–B-based sintered magnet, including general features, an Nd₂Fe₁₄B compound, phase diagram of Nd–Fe–B magnet, manufacturing process and efforts for realising high performance.

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Sagawa, M., Fujimura, S., Togawa, N., Yamamoto, H., Matsuura, Y.: New material for permanent magnets on a base of Nd and Fe (invited). J. Appl. Phys. 55, 2083–2087 (1984) CrossRef

Croat, J.J., Herbst, J.F., Lee, R.W., Pinkerton, F.E.: Pr-Fe and Nd–Fe-based materials: a new class of high-performance permanent magnets (invited). J. Appl. Phys. 55, 2078–2082 (1984) CrossRef

Lee, R.W.: Hot-pressed neodymium-iron-boron magnets. Appl. Phys. Lett. 46, 790–791 (1985) CrossRef

Nakayama, R., Takeshita, T., Itakura, M., Kuwano, N., Oki, K.: Magnetic properties and microstructures of the Nd–Fe–B magnet powder produced by hydrogen treatment. J. Appl. Phys. 70, 3770–3774 (1991) CrossRef

Kronmüller, H., Durst, K.-D., Sagawa, M.: Analysis of the magnetic hardening mechanism in RE-FeB permanent magnets. J. Magn. Magn. Mater. 74, 291–302 (1988) CrossRef

Ramesh, R., Thomas G., Ma, B.M.: Magnetization reversal in nucleation controlled magnets. II. Effect of grain size and size distribution on intrinsic coercivity of Fe–Nd–B magnets. J. Appl. Phys. 64, 6416–6423 (1988) CrossRef

Nothnagel, P., Müller, K.-H., Eckert, D., Handstein, A.: The influence of particle size on the coercivity of sintered NdFeB magnets. J. Magn. Magn. Mater. 101, 379–381 (1991) CrossRef

Scott, D.W., Ma, B.M., Liang, Y.L., Bounds, C.O.: The effects of average grain size on the magnetic properties and corrosion resistance of NdFeB sintered magnets. J. Appl. Phys. 79, 5501–5503 (1996) CrossRef

Uestuener, K., Katter, M., Rodewald, W.: Dependence of the mean grain size and coercivity of sintered Nd–Fe–B magnets on the initial powder particle size. IEEE Trans. Magn. 42, 2897–2899 (2006) CrossRef

10.

Stoner, E.C., Wohlfarth, E.P.: A mechanism of magnetic hysteresis in heterogenious alloys. Phil. Trans. Roy. Soc. 240, 599–642 (1948) CrossRef

11.

Hirosawa, S., Matsuura, Y., Yamamoto, H., Fujimura, S., Sagawa, M., Yamauchi, H.: Magnetization and magnetic anisotropy of R ₂Fe ₁₄B measured on single crystals. J. Appl. Phys. 59, 873–879 (1986) CrossRef

12.

Harbst, J.F., Croat, J.J., Pinkjerton, F.E., Yelon, W.B.: Relationships between crystal structure and magnetic properties in Nd2Fe14B. Phys. Rev. B 29, 4176–4178 (1984) CrossRef

13.

Sagawa, M., Fujimura, S., Yamamoto, H., Matsuura, Y., Hiraga, K.: Permanent magnet materials based on the rare earth-iron-boron tetragonal compounds. IEEE Trans. Magn. 20, 1584–1589 (1984) CrossRef

14.

Sagawa, M., Hirosawa, S., Yamamoto, H., Fujimura, S., Matsuura, Y.: Nd–Fe–B permanent magnetic materials. Jpn. J. Appl. Phys. 26, 785–800 (1987) CrossRef

15.

Harimoto, D., Matsuura, Y.: Development of high performance Nd–Fe–B sintered magnets. Hitachi Metals Tech. Rev. 23, 69–72 (2007). (in Japanese)

16.

Hirose, Y., Hasegawa, H., Sasaki, S., Sagawa, M.: Microstructure of strip cast alloys for high performance NdFeB magnets. In: Proceeding on 15th Rare-Earth Magnets and their Applications, Dresden, pp. 77–86 (1998)

17.

Okada, C., Miyake, Y., Yamamoto, K., Shibamoto, T.: Development of new production method (strip-casting method) for rare-earth magnetic alloys. J. Jpn. Soc. Powder Metall. 55, 517–521 (2008). (in Japanese) CrossRef

18.

Harris, I.R., Noble, C., Bailey, T.: The hydrogen decrepitation of an Nd15Fe77B8 magnetic alloy. J. Less-Common Met. 106, L1–L4 (1985) CrossRef

19.

McGuiness, P.J., Harris, I.R., Rozendaal, E., Ormerod, J., Ward, M.: The production of a Nd–Fe–B permanent magnet by a hydrogen decrepitation/attritor milling route. J. Mater. Sci. 21, 4107–4110 (1986) CrossRef

20.

Vial, F., Joly, F., Nevalainen, E., Sagawa, M., Hiraga, K., Park, K.T.: Improvement of coercivity of sintered NdFeB permanent magnets by heat treatment. J. Magn. Magn. Mater. 242–245, 1329–1334 (2002) CrossRef

21.

Uchida, K., Takahashi, M., Tanighchi, F., Mikamoto, T., Sasaki, K.: High-performance Nd–Fe–B permanent magnets by wet process. HILOP. Hitachi Metals Tech. Rev. 13, 59–64 (1997). (in Japanese)

22.

Sagawa, M., Une, Y.: A new process for producing Nd–Fe–B sintered magnets with small grain size. In: Proceedings on the 20th International Workshop on Rare-Earth Permanent Magnets and their Applications, Crete, pp. 103–105 (2008)

23.

Sagawa, M., Nagata, H.: Novel processing technology for permanent magnets. IEEE Trans. Magn. 29, 2747–2751 (1993) CrossRef

24.

Kaneko, Y., Ishigaki, N.: Recent developments of high-performance NEOMAX magnets. J. Mater. Eng. Performances 3, 228–233 (1994) CrossRef

25.

Kaneko, Y., Tokuhara, K., Sasakawa, Y.: Developing and mass-producing of super high performance 400 kJ/m ³ Nd–Fe–B Magnets. Jpn. Soc. Powder Metall. 47, 139–145 (2000) (in Japanese) CrossRef

26.

Kuniyoshi, F., Nakahara, K., Kaneko, Y.: Developing of 460 kJ/m ³ Nd–Fe–B magnets. Jpn. Soc. Powder Powder Metallurgy 51, 698–702 (2003). (in Japanese) CrossRef

27.

Matsuura, Y., Hoshijima, J., Ishii, R.: Relation between Nd ₂Fe ₁₄B grain alignment and coercive force decrease ratio in NdFeB sintered magnets. J. Magn. Magn. Mater. 336, 88–92 (2013) CrossRef

28.

Park, K.T., Hiraga, K., Sagawa, M.: Effect of metal-coating and consecutive heat treatment on coercivity of thin Nd–Fe–B sintered magnets. In: Proceedings on the 16th International Workshop on Rare-Earth Magnets and Their Applications, Sendai, pp. 257–264 (2000)

29.

Hirota, K., Nakamura, H., Minowa, T., Honshima, M.: Coercivity enhancement by the grain boundary diffusion process to Nd–Fe–B sintered magnets. IEEE Trans. Magn. 42, 2909–2911 (2006) CrossRef

30.

Yoshimura, K., Morimoto, H. Odaka, T.: R-Fe-B rare earth sintered magnet and method for producing same. WO2007/102391 A1 (2007)

31.

Kunieda, R.: Saving methods of heavy rare-earth elements for Nd–Fe–B sintered magnets. Mater. Integr. 24, 270–274 (2011). (in Japanese)

32.

Natsumeda, M.: Motor design method using dy diffused magnets and effect of its application. Hitachi Metals Tech. Rev. 28, 8–13 (2012). (in Japanese)

33.

Watanabe, N., Ito, M., Doi, Y., Hirota, K., Nakamura, H., Minowa, T.: Investigation of demagnetization process of the coercivity distributed Nd–Fe–B sintered magnets. In: Proceedings on the 22nd International Workshop on Rare-Earth Permanent Magnets and Their Applications, Nagawaki, pp. 359–362 (2012)

34.

Une, Y., Sagawa, M.: Enhancement of coercivity of Nd–Fe–B sintered magnets by grain size reduction. J. Jpn. Inst. Metals. 76, 12–16 (2012). (in Japanese) CrossRef

35.

Li, W.F., Ohkubo, T., Hono, K., Sagawa, M.: The origin of coercivity decrease in fine grained Nd–Fe–B sintered magnets. J. Magn. Magn. Mater. 321, 1100–1105 (2009) CrossRef

36.

Sepehri-Amin, H., Ohkubo, T., Shima, T., Hono, K.: Grain boundary and interface chemistry of an Nd–Fe–B-based sintered magnet. Acta Mater. 60, 819–830 (2012) CrossRef

37.

Itakura, M., Watanabe, N., Nishida, M., Daio, T., Matsumura, S.: Atomic-resolution X-ray energy-dispersive spectroscopy chemical mapping of substitutional Dy atoms in a high-coercivity neodymium magnet. Jpn. J. Appl. Phys. 52, 050201 (2013) CrossRef

38.

Sasaki, T.T., Ohkubo, T., Hono, K., Une, Y., Sagawa, M.: Correlative multi-scale characterization of a fine grained Nd–Fe–B sintered magnet. Ultramicroscopy 132, 222–226 (2013) CrossRef

39.

Sasaki, T.T., Ohkubo, T., Hono, K.: Structure and chemical compositions of the grain boundary phase in Nd–Fe–B sintered magnets. Acta Mater. 115, 269–277 (2016) CrossRef

40.

Murakami, Y., Tanigaki, T., Sasaki, T.T., Takeno, Y., Park, H.S., Matsuda, T., Ohkubo, T., Hono, K., Shindo, D.: Magnetism of ultrathin intergranular boundary regions in Nd–Fe–B permanent magnets. Acta Mater. 71, 370–379 (2014) CrossRef

41.

Kohashi, T., Motai, K., Nishiuchi, T., Hirosawa, S.: The magnetism at the grain boundaries of NdFeB sintered magnet studied by spin-polarized scanning electron microscopy (spin SEM). Appl. Phys. Lett. 104, 232408 (2014) CrossRef

42.

Nakamura, T., Yasui, A., Kotani, Y., Fukagawa, T., Nishiuchi, T., Iwai, H., Akiya, T., Ohkubo, T., Gohda, Y., Hono, K., Hirosawa, S.: Direct observation of ferromagnetism in grain boundary phase of Nd–Fe–B sintered magnet using soft X-ray magnetic circular dichroism. Appl. Phys. Lett. 105, 202404 (2014) CrossRef

43.

Sasaki, T.T., Ohkubo, T., Takada, Y., Sato, T., Kato, A., Kaneko, Y., Hono, K.: Formation of non-ferromagnetic grain boundary phase in a Ga-doped Nd-rich Nd–Fe–B sintered magnet. Scripta Mater. 113, 218–221 (2016) CrossRef

Title

Nd–Fe–B-Based Sintered Magnet

Book

Magnetic Material for Motor Drive Systems

Print ISBN: 978-981-329-905-4

Electronic ISBN: 978-981-329-906-1

https://doi.org/10.1007/978-981-32-9906-1

DOI

https://doi.org/10.1007/978-981-32-9906-1_20

Author:

Takeshi Nishiuchi

Publisher

Springer Singapore

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