Journal of Magnetics

The Korean Magnetics Society (한국자기학회)
권호 표지
DOI QR코드

DOI QR Code

Magnetic Properties and Microstructure of Nanocrystalline NdFeB Magnets Fabricated by a Modified Hot Working Process

  • Kim, Hyoung-Tae (Research Center of Advanced Material Development, Chonbuk Natl Univ.) ;
  • Kim, Yoon-Bae (Korea Research Institute of Standards and Science /) ;
  • Jeon, Woo-Yong (Kwangyang Colleg) ;
  • Kim, Hak-Shin (Research Center of Advanced Material Development, Chonbuk Natl Univ.)
  • Published : 2002.12.01
Download PDF
⟨ Previous Next ⟩

Abstract

Magnetic properties, microstructure and texture of NdFeB magnets fabricated by a modified hot working process from commercial melt-spun powders (Magnequench; MQPA, MQPB and MQPB＋) have been investigated. The hot-pressed isotropic magnet made from MQPA powder, which contains higher Nd content than that of MQPB or MQPB＋, shows higher coercivity. The magnet also shows homogenous and fine grains with higher coercivity for higher consolidation pressure. The hot-deformed MQPA magnet shows a strong anisotropy along the press direction with homogeneous platelet Nd$_2$Fe$_{14}$B grains of 50∼100nm in thickness and 200∼500nm in length. The hot-deformed MQPB＋ magnet, however, shows low remanence and low coercivity. The microstructure of the magnet consists of two areas; undeformed Nd$_2$Fe$_{14}$B grains and well-aligned but large grains with 3∼4 $\mu$m in length. Low Nd content attributes to the formation of the two different area.

Keywords

References

  1. Appl. Phys. Lett. v.46 R. W. Lee https://doi.org/10.1063/1.95884
  2. IEEE Trans. Magn. v.MAG-21 R. W. Lee;E. G. Brewer;N. Schaffel
  3. J. Magn. Magn. Mater v.84 R. K. Mishra;T. Y. Chu;L. K. Rabenberg https://doi.org/10.1016/0304-8853(90)90168-P
  4. J. Jap. Inst. metals v.62 no.5 T. Saito;M. Fujita;K. Fikuoka;Y. Synon
  5. J. Appl. Phys. v.79 no.8 S. Guruswamy;M. K. McCarter;J. E. Shield;V. Panchnathan https://doi.org/10.1063/1.361631
  6. J. Appl. Phys. v.83 no.11 M. Leonowicz;W. Kaszuwara;E. Jerieroka;D. Januszewski;G. Mendora;H. A. Davies;J. Paszula https://doi.org/10.1063/1.367580
  7. J. Appl. Phys. v.736 no.10 F. Fukunaga;H. Tomita;M. Wada;F. Yamashita
  8. J. Mater. Res. v.14 no.6 Z. G. Liu;M. Umemoto;S. Hirasawa;H. Kanekyo https://doi.org/10.1557/JMR.1999.0340
  9. IEEE Trans. Magn. v.35 no.5 F. Ymashita;S. Hashimoto;Y. Sasaki https://doi.org/10.1109/20.800506
  10. J. Magn. Magn. Mater v.224 H. T. Kim;Y. B. Kim;H. S. Kim https://doi.org/10.1016/S0304-8853(01)00018-X
  11. J. of Magnetics v.5 no.4 H. T. Kim;Y. B. Kim;H. S. Kim
  12. J. Appl. Phys. v.63 W. C. Chang;T. B. Wu;K. S. Liu https://doi.org/10.1063/1.340732
  13. J. Appl. Phys. v.73 R. K. mishra;V. Panchanathan;J. J. Croat https://doi.org/10.1063/1.352583
  14. J. Alloys Compos v.257 W. Gr$\ "{u}$nberger;D. Hinz;A. Kirchner;K. H. M$\ "{u}$ller;L. Schultz https://doi.org/10.1016/S0925-8388(97)00026-1
  15. IEEE. Trans. Magn. v.282 Lin Li;C. D. Graham