JOM

, Volume 70, Issue 5, pp 661–665 | Cite as

Coercivity Enhancement of Nd-Fe-B HDDR Powder by Grain Boundary Diffusion Process with Rare-Earth Hydride

  • Hee-Ryoung Cha
  • Jae-Gyeong Yoo
  • Youn-Kyoung Baek
  • Dong-Hwan Kim
  • Hae-Woong Kwon
  • Yang-Do Kim
  • Dongyun Lee
  • Jung-Goo Lee
Powder Metallurgy of Non-Ferrous Metals
  • 36 Downloads

Abstract

The grain boundary diffusion (GBD) process with rare-earth hydride was performed to increase the coercivity of hydrogenation–disproportionation–desorption–recombination (HDDR) powder. Before the GBD process, we investigated the effect of post-annealing of the initial HDDR powder on its magnetic properties. Low-temperature annealing reduced the coercivity of the HDDR powder. However, the coercivity decline decreased with increasing annealing temperature, becoming similar to that of the initial powder at 900°C. After the GBD process at 850°C for 1 h, the coercivity increased by about 4 kOe with 4 wt.% NdH x -Cu, forming a thick and continuous grain boundary phase. In addition, the coercivity and remanence of the HDDR powder produced by the GBD process with NdH x -Cu were higher when using NdH x in spite of the same amount of diffusion as at 2 wt.%.

Notes

Acknowledgements

This study was supported by the Korea Institute of Materials Science (KIMS) internal R&D program (Grant No. PNK5590) and Industrial Strategic Technology Development Program (10080382) funded by the Ministry of Trade, Industry & Energy (MI, Korea).

References

  1. 1.
    O. Gutfleisch, M.A. Willard, E. Brück, C.H. Chen, S. Sankar, and J.P. Liu, Adv. Mater. 23, 821 (2011).CrossRefGoogle Scholar
  2. 2.
    K. Hono and H. Sepehri-Amin, Scr. Mater. 67, 530 (2012).CrossRefGoogle Scholar
  3. 3.
    W. Li, T. Ohkubo, K. Hono, T. Nishiuchi, and S. Hirosawa, Appl. Phys. Lett. 93, 052505 (2008).CrossRefGoogle Scholar
  4. 4.
    G. Hrkac, T. Woodcock, K. Butler, L. Saharan, M. Bryan, T. Schrefl, and O. Gutfleisch, Scr. Mater. 70, 35 (2014).CrossRefGoogle Scholar
  5. 5.
    H. Sepehri-Amin, T. Ohkubo, T. Nishiuchi, S. Hirosawa, and K. Hono, Scr. Mater. 63, 1124 (2010).CrossRefGoogle Scholar
  6. 6.
    L. Liu, H. Sepehri-Amin, T. Ohkubo, M. Yano, A. Kato, T. Shoji, and K. Hono, J. Alloys Compd. 666, 432 (2016).CrossRefGoogle Scholar
  7. 7.
    T. Kim, S. Lee, H. Kim, M. Lee, and T. Jang, Acta Mater. 93, 95 (2015).CrossRefGoogle Scholar
  8. 8.
    K. Bae, T. Kim, S. Lee, H. Kim, M. Lee, and T. Jang, J. Alloys Compd. 612, 183 (2014).CrossRefGoogle Scholar
  9. 9.
    A. Gabay, M. Marinescu, W. Li, J. Liu, and G. Hadjipanayis, J. Appl. Phys. 109, 083916 (2011).CrossRefGoogle Scholar
  10. 10.
    T. Akiya, J. Liu, H. Sepehri-Amin, T. Ohkubo, K. Hioki, A. Hattori, and K. Hono, Scr. Mater. 81, 48 (2014).CrossRefGoogle Scholar
  11. 11.
    H. Sepehri-Amin, T. Ohkubo, S. Nagashima, M. Yano, T. Shoji, A. Kato, T. Schrefl, and K. Hono, Acta Mater. 61, 6622 (2013).CrossRefGoogle Scholar
  12. 12.
    H. Sepehri-Amin, L. Liu, T. Ohkubo, M. Yano, T. Shoji, A. Kato, T. Schrefl, and K. Hono, Acta Mater. 99, 297 (2015).CrossRefGoogle Scholar
  13. 13.
    T. Akiya, J. Liu, H. Sepehri-Amin, T. Ohkubo, K. Hioki, A. Hattori, and K. Hono, J. Appl. Phys. 115, 17A766 (2014).CrossRefGoogle Scholar
  14. 14.
    Z. Lin, J. Han, M. Xing, S. Liu, R. Wu, C. Wang, Y. Zhang, Y. Yang, and J. Yang, Appl. Phys. Lett. 100, 052409 (2012).CrossRefGoogle Scholar
  15. 15.
    H. Sepehri-Amin, J. Liu, T. Ohkubo, K. Hioki, A. Hattori, and K. Hono, Scr. Mater. 69, 647 (2013).CrossRefGoogle Scholar
  16. 16.
    R. Mottram, B. Davis, V. Yartys, and I. Harris, Int. J. Hydrogen Energy 26, 441 (2001).CrossRefGoogle Scholar
  17. 17.
    P. Liu, T. Ma, X. Wang, Y. Zhang, and M. Yan, J. Alloys Compd. 628, 282 (2015).CrossRefGoogle Scholar
  18. 18.
    H.R. Cha, K.W. Jeon, J.G. Yu, H.W. Kwon, Y.D. Kim, and J.G. Lee, J. Alloys Compd. 693, 744 (2017).CrossRefGoogle Scholar
  19. 19.
    H.R. Cha, J.H. Yu, Y.K. Baek, H.W. Kwon, Y.D. Kim, and J.G. Lee, J. Magn. 19, 49 (2014).CrossRefGoogle Scholar
  20. 20.
    W. Li, T. Ohkubo, and K. Hono, Acta Mater. 57, 1337 (2009).CrossRefGoogle Scholar
  21. 21.
    T. Kim, S. Lee, S. Namkumg, and T. Jang, J. Alloys Compd. 537, 261 (2012).CrossRefGoogle Scholar
  22. 22.
    K. Takagi, M. Akada, R. Soda, and K. Ozaki, J. Magn. Magn. Mater. 393, 461 (2015).CrossRefGoogle Scholar
  23. 23.
    H. Sepehri-Amin, T. Ohkubo, T. Shima, and K. Hono, Acta Mater. 60, 819 (2012).CrossRefGoogle Scholar
  24. 24.
    H. Okamoto, J. Phase Equilb. Diffus. 36, 183 (2015).CrossRefGoogle Scholar
  25. 25.
    T. Kim, S. Lee, M. Lee, T. Jang, J.W. Kim, Y. Do Kim, and H. Kim, Acta Mater. 66, 12 (2014).CrossRefGoogle Scholar
  26. 26.
    J. Liu, H. Sepehri-Amin, T. Ohkubo, K. Hioki, A. Hattori, T. Schrefl, and K. Hono, Acta Mater. 82, 336 (2015).CrossRefGoogle Scholar

Copyright information

© The Minerals, Metals & Materials Society 2018

Authors and Affiliations

  1. 1.Powder and Ceramics DivisionKorea Institute of Materials ScienceChangwonKorea
  2. 2.Department of Nano Fusion TechnologyPusan National UniversityBusanKorea
  3. 3.Research Center of SG Tech.Star Group Ind. Co., Ltd.DaeguKorea
  4. 4.Department of Materials Science and EngineeringPukyong National UniversityBusanKorea
  5. 5.Department of Materials Science and EngineeringPusan National UniversityBusanKorea

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