Hostname: page-component-7bb8b95d7b-l4ctd Total loading time: 0 Render date: 2024-09-20T09:56:14.988Z Has data issue: false hasContentIssue false
  • English
  • Français

Hydrogenation Disproportionation Desorption Recombination Processes Applied to NdFeB-, SmFe- and SmCo-Type Alloys

Published online by Cambridge University Press:  21 February 2011

O. Gutfleisch ,
M. Kubis ,
A. Handstein ,
K.-H. Müller  and
L. Schultz
O. Gutfleisch
Affiliation:
Institute of Solid State and Materials Research Dresden, P.O.Box 270016, 01171 Dresden, Germany
M. Kubis
Affiliation:
Institute of Solid State and Materials Research Dresden, P.O.Box 270016, 01171 Dresden, Germany
A. Handstein
Affiliation:
Institute of Solid State and Materials Research Dresden, P.O.Box 270016, 01171 Dresden, Germany
K.-H. Müller
Affiliation:
Institute of Solid State and Materials Research Dresden, P.O.Box 270016, 01171 Dresden, Germany
L. Schultz
Affiliation:
Institute of Solid State and Materials Research Dresden, P.O.Box 270016, 01171 Dresden, Germany
Get access

Abstract

Recent aspects of hydrogenation disproportionation desorption and recombination (HDDR) phenomena in NdFeB-, SmFe- and SmCo-type alloys are reviewed in this paper. The effects of additives on hydrogen sorption and magnetic properties are discussed. The possibilities of producing magnetically anisotropic NdFeB HDDR magnets by hot deformation or alternatively pre-aligning and compacting anisotropic powders are described. Current models for the inducement of magnetic anisotropy in NdFeB HDDR powder are summarized and it is shown that anisotropic powder can be produced from a ternary compound when using a modified processing route. The application of ‘extreme’ hydrogenation conditions, namely high hydrogen pressure or reactive milling in a hydrogen atmosphere at enhanced temperatures, allows the disproportionation of thermodynamically very stable compounds such as Sm2Fe17−xGax (x≥l), SmCo5 or Sm2Co17. Reactive milling and subsequent recombination in vacuum lead to structures, of both the disproportionated and the recombined type, which are on a remarkably finer scale than those commonly observed for standard HDDR procedures. Exchange coupling between the nano-scaled grains can result in magnetically single phase behavior despite a multiphase microstructure and in particular for the Sm2Co17 alloy, a remanence enhancement was observed after recombination at temperatures ≤700°C.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 577: Symposium H – Advanced Hard and Soft Magnetic Materials , 1999 , 3
Copyright
Copyright © Materials Research Society 1999

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

[1] Takeshita, T. and Nakayama, R., 10th Intl. Workshop on RE Magnets and their Applications, Kyoto, Japan, 551 (1989)Google Scholar
[2] McGuiness, P. J., Zhang, X. J., Yin, X. J. and Harris, I. R., J. Less-Common Metals 158, 379 (1990)Google Scholar
[3] Nakamura, H., Sugimoto, S., Okada, M. and Homma, M., Materials Chemistry and Physics 32, 280 (1992)Google Scholar
[4] Coey, J.M.D., Proc. of the Intl. Conf. on Ferrites (ICF96), Kyoto, Japan, 1992, p. 1064 Google Scholar
[5] Cao, L., Müller, K.H., Handstein, A., Grünberger, W., Neu, V. and Schultz, L., J. Phys. D: Appl. Phys. 29, 271 (1996)Google Scholar
[6] Harris, I. R., Noble, C. and Bailey, T., J. Less-Common Met. 106, L1 (1985)Google Scholar
[7] Gutfleisch, O., Martinez, N., Verdier, M. and Harris, I.R., J. of Alloys and Comp. 215, 227 (1994)Google Scholar
[8] Fujita, A. and Harris, I.R., IEEE Trans. Magn., vol.30, no.2, 860 (1994)Google Scholar
[9] Nakamura, H., Sugimoto, S., Tanaka, T., Okada, M. and Homma, M., J. Alloys and Comp. 222, 136 (1995)Google Scholar
[10] Sugimoto, S., Gutfleisch, O. and Harris, I.R., J. of Alloys and Comp. 260, 284 (1997)Google Scholar
[11] Dempsey, N.M., Wendhausen, P.A.P., Gebel, B., Miller, K.H. and Coey, J.M.D., Proc. of 14th Intl. Workshop on Rare-Earth Magnets and their Applications, Sao Paolo, Brasil 1996 p.349 Google Scholar
[12] Kirchner, A., GrUnberger, W., Gutfleisch, O., Neu, V., Müller, K.-H. and Schultz, L., J. Phys. D: Appl. Phys. 31, 1660 (1998)Google Scholar
[13] Takeshita, T. and Nakayama, R., 12th Intl. Workshop on RE Magnets and their Applications, Canberra, 670 (1992)Google Scholar
[14] Harris, I.R., Proc. 12th Intl. Workshop on Rare-Earth Magnets and their Appl., Canberra, Australia, 347 (1992)Google Scholar
[15] Buschow, K.H.J., IEEE Trans. Magn., vol. 30, no.2, 565 (1994)Google Scholar
[16] Tomida, T., Sano, N. and Uehara, M., J. Appl. Phys. 81 (11), 7170 (1997)Google Scholar
[17] Tomida, T., Sano, N., Hanafusa, K., Tomizawa, H. and Hirosawa, S., Acta mater. 47, no.3, 875 (1999)Google Scholar
[18] Nakamura, H., Kato, K., Sugimoto, S., Okada, M. and Homma, M., Proc. of 15th Int. Workshop on RE Magnets and their Appl., Dresden, Germany, vol. 1, p. 507 (1998)Google Scholar
[19] Gutfleisch, O. and Harris, I.R., Proc. of 15th Int. Workshop on RE Magnets and their Appl., Dresden, Germany, vol. 1, p. 487 (1998)Google Scholar
[20] Gao, J., Song, X. and Wang, X., J. Alloys and Comp. 267, 270 (1998)Google Scholar
[21] Gutfleisch, O., Matzinger, M., Fidler, J. and Harris, I.R., J. Magn. Magn. Mat. 147, 320 (1995)Google Scholar
[22] Kubis, M., Gutfleisch, O., Mtiller, K.H., Harris, I.R. and Schultz, L., J. Appl. Phys. 83 (11), 6905 (1998)Google Scholar
[23] Kubis, M., Cao, L., Müller, K.H. and Schultz, L., J. Phys. D: Appl. Phys. 30, L51 (1997)Google Scholar
[24] Handstein, A., Kubis, M., Gutfleisch, O., Gebel, B. and Müller, K.-H., J. Magn. Magn. Mat. 192, 73 (1999)Google Scholar
[25] Gutfleisch, O., Kubis, M., Handstein, A., Müller, K.-H. and Schultz, L., Appl. Phys. Lett. 73 (20), 3001 (1998)Google Scholar
[26] Okada, M., Saito, K., Nakamura, H., Sugimoto, S. and Homma, M., J. Alloys and Comp. 231, 60 (1995)Google Scholar
[27] Williamson, G. K. and Hall, W. H., Acta Metall. 1 (1953), 22 Google Scholar
[28] Coey, J. M. D. (Editor), Rare Earth Iron Permanent Magnets, Clarendon Press Oxford, UK (1996), p. 35 Google Scholar
[29] Yeh, X.L., Samwer, K. and Johnson, W.L., Appl. Phys. Lett. 42, 242 (1983)Google Scholar