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High Coercivity Mechanism Of The Die-Upset Hard Magnets Re13.75Fe80.25B6 (Re = Nd, Pr): Possible Correlation To Specific DefectMicrostructure

Published online by Cambridge University Press:  02 July 2020

V.V. Volkov  and
Y. Zhu
V.V. Volkov
Affiliation:
Department of Applied Science, Brookhaven National Laboratory, Upton, NY11973.
Y. Zhu
Affiliation:
Department of Applied Science, Brookhaven National Laboratory, Upton, NY11973.
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Extract

The magnetic properties of permanent magnets are sensitive to their microstructure. In particular, for the family of Nd(Pr)-Fe-B magnets a very different coercivity and energy products may be obtained by several processing techniques. It was experimentally found that a small excess of Nd over the exact phase composition of Nd2Fe14B plays an important role in obtaining high-energy products during the die-upset processing of the anisotropic hard magnets. However the specific role of the Nd excess on both magnetic structure and microstructure of these die-upset magnets is unclear and controversial. Answers to these questions may help to correctly address some major issues in materials science, e.g. how microstructure is related to magnetic structure of hard magnets, and how to optimize the performance of hard magnets.

In-situ TEM magnetizing experiments combined with Lorentz magnetic microscopy in Fresnel-Foucault modes were used to characterize the magnetic structure of die-upset, high energy-product hard magnets Nd13.75Fe80.25B6 and Pr13.75Fe80.25B6.

Type
Magnetic Imaging And Its Application To Materials
Information
Microscopy and Microanalysis , Volume 5 , Issue S2: Proceedings: Microscopy & Microanalysis '99, Microscopy Society of America 57th Annual Meeting, Microbeam Analysis Society 33rd Annual Meeting, Portland, Oregon August 1-5, 1999 , August 1999 , pp. 42 - 43
Copyright
Copyright © Microscopy Society of America

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References

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