Skip to main content
SpringerLink
Log in

In-situ electrical resistivity measurements: study of magnetic and phase transitions and solid-HDDR processes in Nd-Fe-B-type alloys

  • Papers
  • Published:
Journal of Materials Science Aims and scope Submit manuscript

Abstract

Nd-Fe-B-type alloys have been characterized by means of in-situ electrical resistivity measurements. The potential of this technique for monitoring various phenomena relevant to the hydrogenation, disproportionation, desorption and recombination (HDDR) processing of Nd-Fe-B-type alloys is assessed, together with an evaluation of its capacity for delineating magnetic and phase transitions. The effects of external parameters, such as hydrogen pressure and processing temperature, and of intrinsic parameters, such as alloy composition and initial microstructure, on the kinetics of the solid-HDDR process have been investigated. It was found that the amount of neodymium-rich intergranular phase present in the material had a significant influence on the rates of disproportionation and recombination reactions. At 620‡C, the recombination process takes place as a solid-solid reaction, and this has a marked effect on the reaction rate. It was also found that the disproportionation process is very sensitive to the hydrogen pressure and the dependence of the overall process on the processing temperature between 620 and 900‡C has been determined.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  1. F. Gencer and I. I. Harris, J. Mater. Sci. 26 (1991) 6625.

    Article  CAS  Google Scholar 

  2. O. Gutfleisch, M. Verdier, I. R. Harris and A. E. Ray, IEEE Trans. Magn. 29 (1993) 2872.

    Article  CAS  Google Scholar 

  3. O. Gutfleisch, M. Verdier and I. R. Harris, J. Alloys Compos. 196 (1993) L19.

    Article  CAS  Google Scholar 

  4. F. Ahmed, O. Gutfleisch and I. R. Harris, IEEE Trans. Magn. 30 (1994) 616.

    Article  CAS  Google Scholar 

  5. I. R. Harris, in “Proceedings of the 12th International Workshop on Rare-Earth Magnets and their Applications” University of Western Australia, Canberra, Australia (1992) p. 347.

    Google Scholar 

  6. T. Takeshita and R. Nakayama, ibid.in “, p. 67.

    Google Scholar 

  7. P. J. McGuiness, E. J. Devlin, I. R. Harris, E. Rozendaal and J. Ormerod, J. Mater. Sci. 24 (1989) 2541.

    Article  CAS  Google Scholar 

  8. O. Gutfleisch, N. Martinez, M. Verdier and I. R. Harris, J. Alloys Compos. 204 (1994) L21.

    Article  CAS  Google Scholar 

  9. O. Gutfleisch, M. Matzinger, J. Fidler, N. Martinez and I. R. Harris, in “Proceedings of the 8th International Symposium on Magnetic Anisotropy and Coercivity in Rare-Earth-Transition Metal Alloys”, Birmingham, UK, September 1994, p. 243.

  10. C. Mueller, B. Reinsch and G. Petzow, Z. Metallkd. 83 (1992) 845.

    CAS  Google Scholar 

  11. G. Schneider, E. T. Henig, G. Petzow and H. H. Stadelmaier, ibid. 77 (1986) 755.

    CAS  Google Scholar 

  12. D. Book and I. R. Harris, IEEE Trans. Magn. 28 (1992) 2145.

    Article  CAS  Google Scholar 

  13. X. J. Zhang, P. J. McGuiness and I. R. Harris, J. Appl. Phys. 69 (1991) 5838.

    Article  CAS  Google Scholar 

  14. D. Book and I. R. Harris, in “Proceedings of the 8th International Symposium on Magnetic Anisotropy and Coercivity in Rare-Earth-Transition Metal Alloys”, Birmingham, UK, September 1994, p. 205.

  15. O. Gutfleisch, N. Martinez, M. Verdier, and I. R. Harris, J. Alloys Compos., 215 (1994) 227.

    Article  CAS  Google Scholar 

  16. P. J. McGuiness, I. R. Harris, U. D. Scholz and H. Nagel, Z. Phys. Chem. Neue Folge 163 (1989) 687.

    Article  Google Scholar 

  17. N. Martinez, D. G. R. Jones, O. Gutfleisch, D. Lavielle, D. Pere and I. R. Harris, in “6th MMM-Intermag Conference 1994” Albuquerque, New Mexico, USA, J. Appl. Phys. to be published.

  18. K. A. Gschneidner and Leroy Eyring, “Handbook on the Physics and Chemistry of Rare Earths, Vol. 3 (North-Holland, Amsterdam, 1979) p. 229.

    Google Scholar 

  19. R. C. Heckman and C. R. Hills, Bull. Am. Phys. Soc 10 (1965) 126.

    Google Scholar 

  20. C. Ohki, H. Uchida and E. Ko, J. Jpn Inst. Metals 54 (1990) 146.

    Article  CAS  Google Scholar 

  21. K. H. J. Buschow, P. C. P. Bouten and A. R. Meidema, Rep. Prog. Phys. 45 (1982) 937.

    Article  Google Scholar 

  22. T. Takeshita and R. Nakayama, in “Proceedings of the 11th International Workshop on Rare-Earth Magnets and their Applications” Pittsburgh, PA, edited by S. G. Sankar, Carnegie Mellon University (1990) p. 49.

Download references

Author information

Authors and Affiliations

  1. School of Metallurgy and Materials Science, University of Birmingham, B15 2TT, Birmingham, UK

    O. Gutfleisch & I. R. Harris

Authors
  1. O. Gutfleisch
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. I. R. Harris
    View author publications

    You can also search for this author in PubMed Google Scholar

Rights and permissions

Reprints and permissions

About this article

Cite this article

Gutfleisch, O., Harris, I.R. In-situ electrical resistivity measurements: study of magnetic and phase transitions and solid-HDDR processes in Nd-Fe-B-type alloys. Journal of Materials Science 30, 1397–1404 (1995). https://doi.org/10.1007/BF00375238

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF00375238

Keywords

Search

Navigation