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Effect of Cu and Al Substitutions on the Microstructure of R-Fe-B Magnets

Published online by Cambridge University Press:  15 February 2011

Y. J. Zhang
Affiliation:
Department of Physics and Astronomy University of Delaware, Newark, DE 19716
L. Withanawasam
Affiliation:
Department of Physics and Astronomy University of Delaware, Newark, DE 19716
G. C. Hadjipanayis
Affiliation:
Department of Physics and Astronomy University of Delaware, Newark, DE 19716
A. Kim
Affiliation:
Crucible Research, Pittsburgh, PA 15212
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Abstract

The coercivity of melt-spun Pr-Fe-B ribbons was found to increase with the addition of Cu and Al. The change in size and shape of grains with Cu and Al substitution were investigated by transmission eletron microscopy (TEM) and the grain boundary structure was further examined with high resolution electron microscopy (HREM). For small substitutions only “disturbed lattice” regions were observed at most of the grain boundaries. Secondary phases rich in the added elements were observed mostly at tripple grain boundaries and sometimes at grain boundaries in samples with larger amounts of substitution. The grain size in the substituted samples does not decrease much with further substitution. However, the shape of grains changes from polyhexagons to facets. The enhancement in coercivity can be explained by the grain size reduction and the modification of microstructure at the grain boundary regions.

Type
Research Article
Copyright
Copyright © Materials Research Society 1991

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References

REFERENCES

1. Sagawa, M., Fujimura, S., Togawa, N., Yamamoto, H. and Matuura, Y., J. Appl. Phys. 55, 2083 (1984).Google Scholar
2. Croat, J. J., Herbst, J. F., Lee, R. W., and Pinkerton, F. E., J. Appl. Phys. 55, 2078 (1984).Google Scholar
3. Lee, R. W., Appl. Phys. Lett. 46, 790 (1985).Google Scholar
4. Hadjipanayis, G. C. and Gong, W., J. Appl. Phys. 64, 5559 (1988).Google Scholar
5. Hadjipanayis, G. C. and Withanawasam, L., Proceedings of the 11th Intl. Symposium on Magnetiic Anisotropy and Coercivity in Rare Earth-Transition Metal Alloys, II, 530, (1990).Google Scholar
6. Herbst, J. F., Fuerst, C. D., Mishra, R. K., Murphy, C. B. and Wingerden, D. J. Van, 35th Annual Conf. on MMM, Oct.20-Nov. 1, 1990, San Diago, USA.Google Scholar
7. Yajima, K., Nakamura, H. and Yoneyama, T., J. Appl. Phys. 64, 5528 (1988).Google Scholar
8. Koch, K. G., Henig, E-Th. and Fidler, J., J. of MMM. 83, 209 (1990).Google Scholar
9. Fidler, J., Koch, K. G., Kronmuller, K. and Schneider, G., J. Mater.Res. 4, 805 (1989).Google Scholar
10. Grieb, B., Koch, K. G., Henig, E-Th and Petzow, , J. MMM. 80, 75 (1989).Google Scholar
11. Fidler, J., Groiss, C. and Tokunaga, M., IEEE Trans Mag-20 (1990).Google Scholar
12. Sagawa, M., Tenaud, P., Vial, F. and Hiraga, K., Intermag, April 17–20, 1990, Brighton, UK. Google Scholar
13. Schrey, P., J. MMM. 73, 260 (1988).Google Scholar
14. Hadjipanayis, G. C., Zhang, M. and Gao, C., Appl. Phys. Letts. 54, 1812 (1988).Google Scholar
15. Chen, S. K., Duh, J. G. and Ku, K. C., J. Appl. Phys. 62 2739 (1988).CrossRefGoogle Scholar
16. Shimoda, T., Akioka, K., Kobayashi, O. and Yamagami, T., J. Appl. Phys. 64, 5290 (1988).Google Scholar
17. Burzo, E. and Plugaru, N., J. MMM. 86, 98 (1990).Google Scholar
18. Kowalczyk, A. and Wrzeciono, A., J. de Physique C8–605 (1988).Google Scholar
19. Sagawa, M., Fujimura, S., Yamamoto, H., Matsuura, Y. and Hiraga, K., IEEE Trans Mag-20, 1584 (1984).Google Scholar
20. Mishra, R. K., J. MMM. 54–57, 450 (1986).Google Scholar
21. Mishra, R. K., J. Appl. Phys. 62, 967 (1987).Google Scholar
22. Higuchi, A. and Hirasaw, S., IEEE Trans Mag-25, 3555 (1989).Google Scholar
23. Tsubokawa, Y., Hirosawa, S. and Shimizu, R., Proceedings of the 10th Intl. Workshop on rare-earth magnets, II, 459 (1989).Google Scholar
24. Zhang, Y. J., Hadjipanayis, G. C. and Kim, A. S., Proceedings of the 10th Intl. Workshop on rare-earth magnets, 5, II, 250 (1990).Google Scholar
25. Friedberg, R. and Paul, D. I., Phys. Rev. Letts., 34, 1234 (1974).Google Scholar
26. Paul, D. I., Appl. Phys. 53, 1649 (1981).CrossRefGoogle Scholar
27. Hilzinger, H. R., Appl. Phys. 12, 253 (1977).Google Scholar
28. Durst, K.-D. and Kronmuller, H., J.MMM. 59, 86 (1986).Google Scholar