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Microstructural and Magnetic Improvements in Tube-Cast Pr-Fe-B-Cu Alloys Via Heat Treatments and Rapid Upset Forging

Published online by Cambridge University Press:  21 February 2011

G P Hatch ,
A J Williams  and
I R Harris
G P Hatch
Affiliation:
Now at Dexter Magnetic Technologies, 1050 Morse Avenue, Elk Grove Village, IL 60090
A J Williams
Affiliation:
School of Metallurgy and Materials, University of Birmingham, Birmingham BI 5 2TT, UK
I R Harris
Affiliation:
School of Metallurgy and Materials, University of Birmingham, Birmingham BI 5 2TT, UK
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Abstract

Alloys of Pr-Fe-B-Cu were cast into Cu and stainless steel tubes. It could be seen that a preferred crystallographic orientation was obtained after cooling. Fine platelets of Pr2Fe1 4B matrix phase were formed, surrounded by various grain boundary phases, and there was a significant reduction in the amount of free Fe present, in comparison to conventional slab cast alloys. In order to improve the magnetic properties in the as-cast state, two alternative routes were used. The first involved a series of two step heat treatments to develop an improved microstructure. After an optimum heat treatment of 1000 'C for 24 hours + 500°C for 3 hours, significantly improved magnetic properties were obtained for a 17.5 % Pr alloy; Br = 752 mT, Hci = 613 kAm−1 and BHmax = 96 kJm−3. The second route involved a rapid upset forging [RUF] process, with a strain rate of 11.5 s−1, to hot deform the alloys. Following post-forging heat treatments, properties of Br = 966 mT, Hci = 780 kAm−3 and BHmax = 160 kJm−3 were obtained for a 15% Pr alloy. That nature of the improvements in properties as a result of heat treatments and RUF were investigated and are discussed in the present work.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 577: Symposium H – Advanced Hard and Soft Magnetic Materials , 1999 , 69
Copyright
Copyright © Materials Research Society 1999

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References

REFERENCES

[1] Shimoda, T, Akioka, K, Kobayashi, O and Yamagami, T, J. Appl. Phys., 64, p 5290, 1988 Google Scholar
[2] Delamore, G W, Hatch, G P, McGuiness, P J, Mycock, G J and Harris, I R, Proc. 8th International Symposium on Magnetic Anisotropy and Coercivity in Rare Earth Transition Metal Alloys, pp 253–260, Birmingham, 1994 Google Scholar
[3] Hatch, G P, Delamore, G W and Harris, I R, submitted to J. All. Comp., 1999 Google Scholar
[4] Shimoda, T, Akioka, K, Kobayashi, O and Yamagami, T, J. Appl. Phys., 64, pp 5290–5292, 1988aGoogle Scholar
[5] Shimoda, T, Akioka, K, Kobayashi, O and Yamagami, T, J. de Phys., 49, pp 631–632, 1988bGoogle Scholar
[6] Shimoda, T, ‘The Global Business and Technical Outlook for NdFeB Magnet Markets’, Gorham Advanced Marketing Institute, Monterrey, 1989aGoogle Scholar
[7] Shimoda, T, Akioka, K, Kobayashi, O and Yamagami, T, Proc. 10th. International Workshop on Rare Earth Magnets and their Applications, pp 389–398, Kyoto, 1989cGoogle Scholar
[8] Ohki, T, Yuri, T, Miyagawa, M, Takahashi, Y, Yoshida, C, Kambe, S, Higashi, M and Itayama, K, Proc. 10th. International Workshop on Rare Earth Magnets and their Applications, pp 399–407, Kyoto, 1989 Google Scholar
[9] Shimoda, T, Akioka, K, Kobayashi, O, Yamagami, T, Ohki, T, Miyagawa, M and Yuri, T, IEEE. Trans. Magn., 25, pp 4099–4104, 1989bGoogle Scholar
[10] Chang, W C, Paik, C R, Nakamura, H, Takahashi, N, Sugimoto, S, Okada, M and Homma, M, IEEE. Trans. Magn., 26, pp 2604–2606, 1990 Google Scholar
[11] Shimoda, T, Akioka, K, Kobayashi, O, Yamagami, T and Arai, A, Proc. 11 th. International Workshop on Rare Earth Magnets and their Applications, pp 17–28, Pittsburgh, 1990 Google Scholar
[12] Akioka, K, Kobayashi, O, Yamagami, T, Arai, A and Shimoda, T, J. Appl. Phys., 69, pp 5829–5831, 1991 Google Scholar
[13] Chen, Z, Xie, F, Shi, Z, Wang, L and Fu, H, J. Appl. Phys., 70, pp 2868–2870, 1991 Google Scholar
[14] Kwon, H W, Bowen, P and Harris, I R, J. All. Comp., 189, pp 131–137, 1992aGoogle Scholar
[15] Kwon, H W, Bowen, P and Harris, I R, Proc. 12th. International Workshop on Rare Earth Magnets and their Applications, pp 705–719, Canberra, 1992bGoogle Scholar
[16] Iwamura, E, Yuri, T, Hanaki, A, Mitani, H and Itayama, K, Proc. 12th. International Workshop on Rare Earth Magnets and their Applications, pp 384–391, Canberra, 1992 Google Scholar
[17] Luo, Y and Xia, T-S, Proc. 12th. International Workshop on Rare Earth Magnets and their Applications, pp 473–481, Canberra, 1992 Google Scholar
[18] Hatch, G P, Williams, A J, Mycock, G J and Harris, I R, J. Mag. Magn. Mats., 157/158, pp 69–70, 1996 Google Scholar
[19] Hatch, G P, Williams, A J, Harris, I R and Mycock, G J, Proc. 14th International Workshop on Rare Earth Magnets and their Applications, pp 501–510, Sao Paulo, 1996 Google Scholar
[20] Hatch, G P, Williams, A J and Harris, I R, submitted to J. Mag. Magn. Mats., 1999 Google Scholar
[21] Ferrante, M, Sinka, V, Assis, O B G, Oliveira, I de and Freitas, E de, Proc. 14th. International Workshop on Rare Earth Magnets and their Applications, pp 255–263, Sao Paulo, 1996 Google Scholar
[22] Hatch, G P, Williams, A J and Harris, I R, submitted to J. Mag. Magn. Mats., 1999Google Scholar
[23] Kwon, H W, Bowen, P and Harris, I R, J. All. Comp., 182, pp 233–242, 1992 Google Scholar
[24] Faria, R N J, PhD thesis, University of Birmingham, 1993 Google Scholar
[25] Leonowicz, M, McGuiness, P J, Hatch, G P, Davies, H A and Harris, I R, J. Mag. Magn. Mats., 166, pp 165–171, 1997 Google Scholar