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Structure and Magnetic Properties of Nd–Fe–B Magnets Prepared from DyH2-Containing Powder Mixtures

  • Composite Materials
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Inorganic Materials: Applied Research Aims and scope

Abstract

Sintered Nd–Pr–Dy–Fe–B permanent magnets were prepared by a powder blending technique using mixtures consisting of strip-casting alloy (wt %) 24.0 Nd, 6.5 Pr, 0.5 Dy, 1.0 B, 0.2 Al, 65.8 Fe and 2 wt % DyH2 dysprosium hydride. After optimum heat treatment of magnets at 500°C for 1 h, the following hysteretic characteristics were reached: remanence B r = 1.29 T; coercive force j H c = 1309 kA/m; critical field H k = 1220 kA/m; and the maximum energy product (BH)max = 322 kJ/m3. The characteristic peculiarity of the magnets prepared from hydride-containing power mixtures is the stability of hysteretic properties in the course of subsequent stepped annealings or progressive heatings at temperatures of 250–500°C for, in total, more than 20 h. Conditions of low-temperature annealings resulting in the degradation and subsequent restoration of hysteretic properties of magnets are determined. The evolution of the microstructure and phase composition of magnets in the course of heat treatments was studied by X-ray diffraction analysis and scanning electron microscopy, and the correlation between the structural changes and hysteretic properties of magnets is discussed.

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Authors and Affiliations

  1. Baikov Institute of Metallurgy and Materials Science, Russian Academy of Sciences, Moscow, 119334, Russia

    G. S. Burkhanov & N. B. Kolchugina

  2. JSC Spetsmagnit, Moscow, 127238, Russia

    A. A. Lukin & V. V. Sitnov

  3. International Laboratory of High Magnetic Fields and Low Temperatures, Polish Academy of Sciences, Wroclaw, 53-421, Poland

    Yu. S. Koshkidko & J. Cwik

  4. Vysoka Skola Banska—TUO, Ostrava-Poruba, 70833, Czech Republic

    K. Skotnicova

Authors
  1. G. S. Burkhanov
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  2. N. B. Kolchugina
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  3. A. A. Lukin
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  4. Yu. S. Koshkidko
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  5. J. Cwik
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  6. K. Skotnicova
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  7. V. V. Sitnov
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Correspondence to G. S. Burkhanov.

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Original Russian Text © G.S. Burkhanov, N.B. Kolchugina, A.A. Lukin, Yu.S. Koshkidko, J. Cwik, K. Skotnicova, V.V. Sitnov, 2017, published in Fizika i Khimiya Obrabotki Materialov, 2017, No. 5, pp. 44–54.

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Burkhanov, G.S., Kolchugina, N.B., Lukin, A.A. et al. Structure and Magnetic Properties of Nd–Fe–B Magnets Prepared from DyH2-Containing Powder Mixtures. Inorg. Mater. Appl. Res. 9, 509–516 (2018). https://doi.org/10.1134/S2075113318030115

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  • DOI: https://doi.org/10.1134/S2075113318030115

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