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Synthesis of ultrastrong nanocomposite-permanent magnet with magnetic anisotropy

Research Project

Project/Area Number 15360384
Research Category

Grant-in-Aid for Scientific Research (B)

Allocation TypeSingle-year Grants
Section一般
Research Field Material processing/treatments
Research InstitutionToyama University

Principal Investigator

MAJIMA Kazuhiko  Toyama University, Faculty of Engineering, Professor, 工学部, 教授 (60029270)

Co-Investigator(Kenkyū-buntansha) MATSUDA Kenji  Toyama University, Faculty of Engineering, Associate Professor, 工学部, 助教授 (00209553)
Project Period (FY) 2003 – 2005
Project Status Completed (Fiscal Year 2005)
Budget Amount *help
¥7,600,000 (Direct Cost: ¥7,600,000)
Fiscal Year 2005: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2004: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2003: ¥5,600,000 (Direct Cost: ¥5,600,000)
Keywordsrare-earth magnet / soft and hard magnet / nanoocmposite magnet / exchange-spring magnet / remanence / coecivity / ultra-high mangetization / ultra-high mangetization / hard and soft composite magnet / nanocomposite magnet / ultra-giant magnetization / rare-earth magnets / nano-composits magnets / magnetic anisotropy / hard magnet / soft magnet / corrosion / electrochemical method / Nyquist diagram / hard magnetic material / soft magnetic material / rase-earth magnet / coercivity / magnetization / maximam energy product
Research Abstract

Nanocomposite permanent magnets have become more attractive as new magnetic materials. Recently, mechanical alloying (MA) and the melt-spinning method have been applied to the production of nanocomposite magnets such as Nd_2Fe_<14>B+α-Fe(Fe_3B),Sm_2Fe_<17>Nx+α-Fe,SmCo_5+α-Fe, etc. These nonocomposite magnets, however, are magnetically isotropic, and a magnetically anisotropic composite magnet is significantly required. We have tried to synthesize magnetically anisotropic powders in the Sm_2Fe_<17>Nx+α-Fe. Generally, an anisotropic Sm_2Fe_<17>Nx single hard phase was produced by the mechanical grinding (MG) of coarse Sm-Fe mother alloy powders into about 1 μm and subsequent nitriding. Mixtures of the Sm-Fe mother alloy powder and the commercial α-Fe powder were mechanically ground and subsequently nitrided. An exchange coupling between the hard and soft magnetic phases could not be obtained, because it was difficult to pulverize the α-Fe powder into nanoscale particles. According to the … More Sm-Fe binary diagram, the Fe phase and Sm_2Fe_<17> phase coexist on the Fe-rich side from the composition of Sm_2Fe_<17>. Based on this fact, we tried to prepare the Sm_2Fe_<17>Nx+α-Fe composite alloy powders by Sm evaporation during heat treatment at 1273 K in a vacuum from the mechanically ground Sm_2Fe_<17> alloy powder and subsequent nitriding. However, it was found that the properties as a permanent magnet were hardly obtained because of the significant oxidation of these fine powders during sample preparation. On the other hand, we have prepared the anisotropic powder of the Sm_2Fe_<17>Nx single hard phase, which has a grain size of about 300 nm, by MG in NH_3 for a short time using a rotary ball mill with subsequent nitriding. Based on these findings, the synthesis of magnetically anisotropic Sm_2Fe_<17>Nx+α-Fe composite alloy powders was tried by Sm evaporation from the Sm-Fe mother alloy at 1227 K in a vacuum, MG in NH_3 and nitriding. The powders were composed of the Sm_2Fe_<17>Nx+α-Fe phase possessed a magnetic anisotropy, and showed a reversible magnetization reaching 66.8 %. This result indicates that a satisfactory exchange coupling between the soft and hard phases. These powders also showed a magnetic anisotropy, which can align the directions of the c-axis of each hard particle in an applied magnetic field. Including the above mentioned permanent nanoccomposite magnets, all of the strong permanent magnets are produced by using rare-earth alloys. However, the rare-earth magnets are notorious for their poor corrosion resistance. In this study, the Nd-Fe-B magnet produced by HDDR (hydrogen decomposition desorption recombination) process was selected as the representative rare-earth magnet, and its corrosion behavior was investigated through the potentiodynamic polarization curve and Nyquist plot by electrochemical impedance spectroscopy. As the result, it was confirmed that the excellent corrosion resistant film was formed on the specimen surface polarized strongly to a cathodic region. Less

Report

(4 results)
  • 2005 Annual Research Report   Final Research Report Summary
  • 2004 Annual Research Report
  • 2003 Annual Research Report
  • Research Products

    (16 results)

All 2005 2004 2003 Other

All Journal Article (14 results) Publications (2 results)

  • [Journal Article] Corrosion Assessment of Nd-Fe-B Alloy with Co Addition through Impedance Measurement2005

    • Author(s)
      S.Sunad, K.Majima, Y.Akasofu, Y.Kaneko
    • Journal Title

      Journal of Alloys and Compounds (to be published)

    • Related Report
      2004 Annual Research Report
  • [Journal Article] Electrochemical Behavior of Nd-Fe-B Permanent Magnetic Alloys with Co Addition2004

    • Author(s)
      S.Sunada, Y.Akasofu, Y.Kaneko, K.Majima
    • Journal Title

      Abstracts of 2004 Joint International Meeting of the Electrochemical Society (CD-ROM)

    • Related Report
      2004 Annual Research Report
  • [Journal Article] Effects of N_2 mixed gas atomization on electrochemical properties of Mm(Ni,Co,Mu,Al)_<5.0> alloy powder2004

    • Author(s)
      K.Yanagimoto, S.Sunada, K.Majima, T.Sawada
    • Journal Title

      Journal of Alloys and Compounds Vol.372

      Pages: 208-212

    • Related Report
      2004 Annual Research Report
  • [Journal Article] Effects of surface modification on surface structure and electrochemical properties of Mm(Ni,Co,Mu,Al)_<5.0> alloy powder2004

    • Author(s)
      K.Yanagimoto, K.Majima, S.Sunada, T.Sawada
    • Journal Title

      Journal of Alloys and Compounds Vol.377

      Pages: 174-178

    • Related Report
      2004 Annual Research Report
  • [Journal Article] Effect of Si and Al content on core loss in Fe-Si-Al powder core2004

    • Author(s)
      K.Yanagimoto, K.Majima, S.Sunada, T.Sawada
    • Journal Title

      IEEE Transactions on Magnetics 40・3

      Pages: 1691-1694

    • Related Report
      2004 Annual Research Report
  • [Journal Article] Effects of powder compositions on GHz microwave absorption of EM absorbing sheets2004

    • Author(s)
      K.Yanagimoto, K.Majima, S.Sunada, Y.Aikawa
    • Journal Title

      Journal of Powder and Powder Metallurgy 51・4

      Pages: 293-296

    • NAID

      10012887075

    • Related Report
      2004 Annual Research Report
  • [Journal Article] Nd-Fe-B系今金のCo置換による耐食性改善効果2003

    • Author(s)
      福住正文, 金子祐治, 真島一彦
    • Journal Title

      粉体および粉末冶金 50・1

      Pages: 41-44

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Effects of Co addition on improving the corrosion resistance of Nd-Fe-B alloy2003

    • Journal Title

      Journal of the Japan Society of Powder and Powder Metallurgy 50・1

      Pages: 41-44

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Corrosion assessment of Nd-Fe-B alloy with Co addition through impedance measurements

    • Author(s)
      S.Sunada, K.Majima, Y.Akasofu, Y.Kaneko
    • Journal Title

      Journal of Alloys and Compounds (in press)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Electrochemical behavior of aluminum-coated Nd-Fe-B alloy

    • Author(s)
      K.Majima, S.Sunada, H.Ito, Y.Kaneko
    • Journal Title

      Journal of Alloys and Compounds (in press)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Corrosion assessment of Nd-Fe-B alloy with Co addition through impedance measurements

    • Author(s)
      S.Sunada, K.Majima, Y.Akasofu, Y.Kaneko
    • Journal Title

      Journal of Alloys and Compounds (in press)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Electrochemical behavior of aluminum-coated Nd-Fe-B alloy

    • Author(s)
      K.Majima, S.Sunada, H.Ito, Y.Kaneko
    • Journal Title

      Journal of Alloys and Compounds (in press)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2005 Final Research Report Summary
  • [Journal Article] Corrosion assessment of Nd-Fe-B alloy with Co addition through impedance measurements

    • Author(s)
      S.Sunada, K.Majima, Y.Akasofu, Y.Kaneko
    • Journal Title

      Journal of Alloys and Compounds (In press)

    • Related Report
      2005 Annual Research Report
  • [Journal Article] Electrochemical behavior of aluminum-coated Nd-Fe-B alloy

    • Author(s)
      K.Majima, S.Sunada, H.Ito, Y.Kaneko
    • Journal Title

      Journal of Alloys and Compounds (In press)

    • Related Report
      2005 Annual Research Report
  • [Publications] M.Ito, K.Majima, S.Katsuyama: "Effects of partial substitution of V and Ti for Fe on nitrogenation rate and magnetic properties of Sm_2Fe_<17>N_x anisotropic coarse powders"J.Alloys and Compounds. vol.349. 334-340 (2003)

    • Related Report
      2003 Annual Research Report
  • [Publications] 福住正文, 金子裕治, 真島一彦: "Nd-Fe-B系合金のCo置換による耐食性改善効果"粉体および粉末冶金. 51・1. 41-44 (2003)

    • Related Report
      2003 Annual Research Report

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Published: 2003-04-01   Modified: 2016-04-21  

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