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Improved thermal stability of hard magnetic properties in rapidly solidified RE–TM–B alloys

Published online by Cambridge University Press:  31 January 2011

Z.W. Liu ,
R.V. Ramanujan  and
H.A. Davies
Z.W. Liu*
Affiliation:
School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore; Department of Engineering Materials, University of Sheffield, Sheffield S1 3JD, United Kingdom; and School of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, People’s Republic of China
R.V. Ramanujan
Affiliation:
School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore
H.A. Davies
Affiliation:
Department of Engineering Materials, University of Sheffield, Sheffield S1 3JD, United Kingdom
*
a)Address all correspondence to this author. e-mail: [email protected], [email protected]
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Abstract

Rapidly solidified nanocrystalline RE–TM–B (RE = Nd, Pr, Dy, TM = Fe, Co) alloys with enhanced hard magnetic properties were synthesized by melt spinning. The composition- and microstructure-dependent elevated temperature magnetic properties were investigated. The temperature coefficients of remanence (α) and coercivity (β) were determined. The effects of Pr substituting Nd, Co substituting Fe, Dy substituting RE, and grain size on the Curie temperature and thermal stability were studied. Co or Dy substitutions were found to have a significant beneficial effect on the thermal stability. Reducing grain size could also improve elevated temperature behavior. Maximum energy product (BH)max > 100 kJ/m3 could be obtained in compositionally optimized nanophase alloys at temperature of 473 K. Extremely low coefficients of α and β were realized in exchange coupled nanocomposite alloys. Bonded nanocomposite magnets with α = −0.052%/K and β = −0.0365%/K for 300–400 K were also successfully fabricated.

Keywords

Magnetic propertiesNanoscaleRapid solidification
Type
Articles
Information
Journal of Materials Research , Volume 23 , Issue 10 , October 2008 , pp. 2733 - 2742
Copyright
Copyright © Materials Research Society 2008

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References

REFERENCES

1McCallum, R.W., Kadin, A.M., Clement, G.B., Keem, J.E.: High-performance isotropic permanent-magnet based on Nd–Fe–B. J. Appl. Phys. 61, 3577 1987CrossRefGoogle Scholar
2Clemente, G.B., Keem, J.E., Bradley, J.P.: The microstructural and compositional influence upon HIREM behavior in Nd2Fe14B. J. Appl. Phys. 64, 5299 1988CrossRefGoogle Scholar
3Manaf, A., Buckley, R.A., Davies, H.A.: New nanocrystalline high-remanence Nd–Fe–B alloys by rapid solidification. J. Magn. Magn. Mater. 128, 302 1993CrossRefGoogle Scholar
4Xiao, Y., Liu, S., Mildrum, H., Strnat, K.J., Ray, A.E.: The effects of various alloying elements on modifying the elevated temperature magnetic properties of sintered Nd–Fe–B magnets. J. Appl. Phys. 63, 3516 1988CrossRefGoogle Scholar
5Mendoza-Suarez, G., Davies, H.A., Escalante-Garicia, J.I.: jH c, J r and (BH)max relationship in PrFeB melt spun alloys. J. Magn. Magn. Mater. 218, 97 2000CrossRefGoogle Scholar
6Davies, H.A., Betancourt, J.I.R., Harland, C.L.: Nanophase (Nd/Pr)2Fe14B/α-Fe alloys: Attractive materials for isotropic magnets with enhanced properties. Scr. Mater. 44, 1337 2001CrossRefGoogle Scholar
7Liu, Z.W., Davies, H.A.: Influence of Co substitution for Fe on the magnetic properties of nanocrystalline (Nd,Pr)–Fe–B based alloys. J. Phys. D: Appl. Phys. 39, 2647 2006CrossRefGoogle Scholar
8Szmaja, W.: Investigations of the domain structure of anisotropic sintered Nd–Fe–B-based permanent magnets. J. Magn. Magn. Mater. 301, 546 2006CrossRefGoogle Scholar
9Liu, Z.W., Davies, H.A.: Sub-ambient magnetic properties of nanophase Nd/Pr–Fe–B based hard magnetic alloys. J. Alloy. Compd. 424, 255 2006CrossRefGoogle Scholar
10Liao, L.X., Altounian, Z., Ryan, D.H.: Cobalt site preferences in iron rare-earth-based compounds. Phys. Rev. B 47, 11230 1993CrossRefGoogle ScholarPubMed
11Lewis, L.H., Panchanathan, V., Wang, J-Y.: Technical magnetic properties of melt-spun (Nd1−xPrx)2Fe14B at low temperature. J. Magn. Magn. Mater. 176, 288 1997CrossRefGoogle Scholar
12Huang, M.Q., Boltich, E.B., Wallace, W.E.: Magnetic characteristics of R2(Fe, Co)14B systems (R = Y, Nd and Gd). J. Magn. Magn. Mater. 60, 270 1986CrossRefGoogle Scholar
13Burzo, E.: Permanent magnets based on R–Fe–B and R–Fe–C alloys. Rep. Prog. Phys. 61, 1099 1998CrossRefGoogle Scholar
14Hirosawa, S., Matsuura, Y., Yamamoto, H., Fujimura, S., Sagawa, M., Yamauchi, H.: Magnetization and magnetic anisotropy of R2Fe14B measured on single crystals. J. Appl. Phys. 59, 873 1986CrossRefGoogle Scholar
15Hirosawa, S., Sagawa, M.: Effects of Co addition on the temperature dependence of the intrinsic coercivity in Pr–Fe–B sintered magnets. J. Appl. Phys. 64, 5553 1988CrossRefGoogle Scholar
16Grössinger, R., Harada, H., Keresztes, A., Kirchmayr, H., Tokunaga, M.: Anisotropy and hysteresis studies of highly substituted Nd–Fe–B based permanent magnets. IEEE Trans. Magn. 23, 2117 1987CrossRefGoogle Scholar
17Hirosawa, S., Tokuhara, K., Yamamoto, H., Fujimura, S., Sagawa, M., Yamauchi, H.: Magnetization and magnetic anisotropy of R2Co14B and Nd2(Fe1−x Cox)14B measured on single crystals. J. Appl. Phys. 61, 3571 1987CrossRefGoogle Scholar
18Bonnenberg, D., Hempel, K.A., Wijn, H.P.: Magnetic Properties of 3d, 4d and 5d Elements, Alloys and Compounds, edited by K-H. Hellwege and O. Madelung, Landolt-Bornstein, New Series Springer-Verlag Berlin 1986 Vol. III/19a, 16Google Scholar
19Liu, Z.W., Davies, H.A.: The practical limits for enhancing magnetic property combinations for bulk nanocrystalline NdFeB alloys through Pr, Co and Dy substitutions. J. Magn. Magn. Mater. 313, 337 2007CrossRefGoogle Scholar
20Liu, Z.W., Davies, H.A.: Irreversible magnetic losses for melt-sun nanocrystalline Nd/Pr–(Dy)–Fe/Co–B ribbons. J. Phys. D: Appl. Phys. 40, 315 2007CrossRefGoogle Scholar
21Jurczyk, M.: Nanocomposite Nd–Fe–B type magnets. J. Alloys Compd. 299, 283 2000CrossRefGoogle Scholar
22Goll, D., Seeger, M., Kronmüller, H.: Magnetic and microstructural properties of nanocrystalline exchange coupled PrFeB permanent magnets. J. Magn. Magn. Mater. 185, 49 1998CrossRefGoogle Scholar
23Liu, Z.W.: The sub-ambient, ambient and elevated temperature magnetic properties of nanophase Nd/Pr–Fe–B based alloys.Ph.D. Thesis, University of Sheffield Sheffield, UK 2005Google Scholar
24Herbst, J.F.: R2Fe14B materials: Intrinsic properties and technological aspects. Rev. Mod. Phys. 63, 819 1991CrossRefGoogle Scholar
25Lee, R.W., Brewer, E.G., Schaffel, N.A.: Processing of neodymium-iron-boron melt-spun ribbons to fully dense magnets. IEEE Trans. Magn. 21, 1958 1985CrossRefGoogle Scholar
26Ray, A.E., Gauder, D.R., Froning, M.H., White, R.J.: Long term aging and irreversible losses at elevated temperatures of Nd–Fe–B magnets with cobalt and dysprosium additions. J. Magn. Magn. Mater. 80, 71 1989CrossRefGoogle Scholar
27Lee, R.W.: Hot-pressed neodymium-iron-boron magnets. Appl. Phys. Lett. 46, 790 1985CrossRefGoogle Scholar