• Title/Summary/Keyword: Nd-Fe-B 합금

Search Result 86, Processing Time 0.027 seconds

Effect of Blending Aids the Magnetic Properties of Anisotropic NdFeB Magnet Prepared by CAPA Process (통전가압법으로 제조한 이방성 NdFeB 영구자석의 자기특성에 미치는 첨가제의 영향)

  • Kim, H.T.;Cho, S.H.;Kim, Y.B.;Kim, H.S.
    • Journal of the Korean Magnetics Society
    • /
    • v.12 no.3
    • /
    • pp.88-93
    • /
    • 2002

  • Rapidly solidified NdFeB powders were mixed with fine powders of pure metal elements before CA-press employed to obtain a fully dense isotropic precursor. Subsequently, the precursor was deformed by CA-deformation to obtain an anisotropic magnet. The CA-deformed anisotropic NdFeB magnets with 0.3 wt.% Zn or Sn exhibited the coercivities about 80% higher (11.4. and 11.2 kOe, respectively) than that (6.4 kOe) of the additive-free magnet.

  • https://doi.org/10.4283/JKMS.2002.12.3.088 인용 PDF KSCI

Improving Reproducibility of Coercivity of HDDR-treated Nd-Fe-B-type Material by Controlling Hydrogen Decrepitation (수소파쇄 제어를 통한 HDDR 처리한 Nd-Fe-B계 재료의 보자력 재현성 향상)

  • Kim, Kyung Min;Kim, Ja Young;Kwon, Hae-Woong;Lee, Jeong Gu;Yu, Ji Hun
    • Journal of the Korean Magnetics Society
    • /
    • v.25 no.4
    • /
    • pp.111-116
    • /
    • 2015

  • Practical difficulty in the HDDR (hydrogenation - disproportionation - desorption - recombination) processing of Nd-Fe-B-type alloy is a poor reproducibility of coercivity of the HDDR-treated material. In an attempt to improve the reproducibility of coercivity of the HDDR-treated $Nd_{12.5}Fe_{80.6}B_{6.4}Ga_{0.3}Nb_{0.2}$ alloy, the hydrogen decrepitation was carefully controlled so as to induce more extensive micro-cracks in the particle. Prior to the hydrogenation and disproportionation reaction of HDDR processing, an additional hydrogen degassing was carried out at an elevated temperature of $600^{\circ}C$ under vacuum for the previously hydrogen decrepitated particle. During the additional hydrogen degassing the lattice of hydrogen absorbed $Nd_2Fe_{14}B$ phase was further shrunken, hence more microcracks were introduced in the particle due to its brittle nature. Particles with more micro-cracks had more homogeneous hydrogen absorption and desorption reaction during the HDDR-treatment. The improved reproducibility of coercivity of the HDDR-treated material was attributed to the improved homogeneity of the HDDR reactions due to the presence of more micro-cracks.

  • https://doi.org/10.4283/JKMS.2015.25.4.111 인용 PDF KSCI