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Enhancement of magnetic properties by controlling structures

Research Project

Project/Area Number 07455275
Research Category

Grant-in-Aid for Scientific Research (B)

Allocation TypeSingle-year Grants
Section一般
Research Field Structural/Functional materials
Research InstitutionThe University of Tokyo

Principal Investigator

UMEDA Takateru  The Univ.of Tokyo, Dept.of Metallurgy, Professor, 大学院・工学系研究科, 教授 (50011078)

Co-Investigator(Kenkyū-buntansha) NAGAYAMA Katsuhisa  Shibaura Institute of Technology, Faculty of Eng, Assistant Professor, 工学部, 助教授 (80189167)
OKANE Toshimitsu  The Univ.of Tokyo Dept.of Metallurgy, Research Associate, 大学院・工学系研究科, 助手 (80251362)
Project Period (FY) 1995 – 1996
Project Status Completed (Fiscal Year 1996)
Budget Amount *help
¥7,200,000 (Direct Cost: ¥7,200,000)
Fiscal Year 1996: ¥3,400,000 (Direct Cost: ¥3,400,000)
Fiscal Year 1995: ¥3,800,000 (Direct Cost: ¥3,800,000)
Keywordsrare earth permanent magnets / Nd2Fe14B / rare earth magnetostrictive alloys / Tb-Dy-Fe phase diagram / Laves phase / phase selection / Tb-Dy-Fe状態図
Research Abstract

This research aims to present a guide line to improve significantly magnetic properties of rare earth permanent magnets and magnetostrictive alloys by controlling solidified and heat-treated structures. For Nd-Fe-B permanent magnetic alloys, increasing of amount of Nd_2Fe_<14>B phases is necessary to enhance magnetic properties. Therefore an initial composition range is expanded to a stable phase range of primary crystallization of gamma-Fe instead of Nd_2Fe_<14>B and also prediction of metastable Nd_2Fe_<14>B is made by using a recent dendritic growth theory considered with phase selection criterion. (TbDy) Fe_2 alloy has excellent magnetostrictive properties and thus exhibits extensive applications such as being transducer and actuator materials. To achieve higher properties, it is necessary to investigate the solidification behavior, crystal growth and magnetostrictive performance of the (TbDy) Fe_2 Laves phase, and thus obtain the crystals with well controlled microstructures.
1.Pha … More se selection in the Nd-Fe-B system
Near-stoichiometric Nd-Fe-B alloys were prepared with a rapid solidification method using melt-spinning technique. Crystallization of the metastable Nd_2Fe_<14>B was realized. Its relationships of to alloy composition, solidification velocity was clarified. Furthermore, the phase selection between the Nd_2Fe_<14>B and gamma-Fe was quantitatively predicted on the basis of a dendritic growth theory.
2.Growth of <111>-oriented Tb-Dy-Fe single crystal
Magnetostriction of the Tb-Dy-Fe alloy is highly anisotropic with the best properties along its <111> directions. However, growth of <111>-oriented single crystal was very difficult according to previous studies. In the present research, <111>-oriented Tb-Dy-Fe single crystals were grown successfully with a careful consideration on the preferred growth and twinned re-entrant stepped growth mechanism. Furthermore, the effects of alloy composition and growth conditions on the <111> growth were clarified.
3.Characterization of the magnetostrictive properties of the (TbDy) Fe_2 crystals
The magnetistrictive properties of <112>-, <110>- and <111>-oriented Tb-Dy-Fe crystals were measured. Higher properties were found in the <110> crystals than usually used <112> one. In the <111> single crystals, the largest magnetostrictive jump and the lowest saturation magnetic field in the world were obtained Less

Report

(3 results)
  • 1996 Annual Research Report   Final Research Report Summary
  • 1995 Annual Research Report
  • Research Products

    (15 results)

All Other

All Publications (15 results)

  • [Publications] Wu Mei: "Directional Solidification of Tb0.3Dy0.7Fe1.90 Magnetostrictive Alloy" J.Alloys & Compounds. (1997)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1996 Final Research Report Summary
  • [Publications] Wu Mei: "Phase Diagram and Inhomogeneity of (TbDy)-Fe(T)(T=Mn,Co,Al,Ti)System" J.of Alloys and Compounds. (1997)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1996 Final Research Report Summary
  • [Publications] Takateru Umeda: "Phase Selection During Solidification of Peritectic Alloys" Acta Metall.Mater.44,10. 4209-4216 (1996)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1996 Final Research Report Summary
  • [Publications] Wu Mei: "Crystal Growth of Giant Magnetostrictive Tb-Dy-Fe Alloy" J.of Alloys and Compounds. (1997)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1996 Final Research Report Summary
  • [Publications] Wu Mei: "Directional Solidification of Tb0.3Dy0.7Fe1.90 Magnetostrictive Alloy" J.Alloys & Conmpounds. accepted for publications.

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1996 Final Research Report Summary
  • [Publications] Takateru Umeda: "Phase Selection During Solidification of Peritectic Alloys" Acta Metall.Mater.Vol.44, No.10. 4209-4216 (1996)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1996 Final Research Report Summary
  • [Publications] Wu Mei: "Phase Diagram and Inhomogeneity of (TbDy) -Fe (T) (=Mn, Co, Al, Ti) System" J.of Alloys and Conmpounds. (accepted for publications).

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1996 Final Research Report Summary
  • [Publications] Wu Mei: "Crystal Growth of Giant Magnetostrictive Tb-Dy-Fe Alloy" J.of Alloys and Conmpounds. (accepted for publications).

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1996 Final Research Report Summary
  • [Publications] Wu Mei: "Directional Solidification of Tb0.3Dy0.7Fe1.90 Magnetostrictive Alloy" J.Alloys & Compoundsに掲載許可済み.

    • Related Report
      1996 Annual Research Report
  • [Publications] Wu Mei: "Phase Diagram and Inhomogeneity of(TbDy)-Fe(T)(T=Mn,Co,Al,Ti)System" J.of Alloys and Compoundsに掲載許可済み.

    • Related Report
      1996 Annual Research Report
  • [Publications] Takateru Umeda: "Phase Selection During Solidification of Peritectic Alloys" Acta Metall.Vol.4,No.10. 4209-4216 (1996)

    • Related Report
      1996 Annual Research Report
  • [Publications] Wu Mei: "Directional Solidification of Tb_<0.3>Dy_<0.7>Fe_<190> Magnetostrictive Alloy" J.of Alloys and Compounds. (発表予定). (1996)

    • Related Report
      1995 Annual Research Report
  • [Publications] Wu Mei: "Phase Diagram and Inhomogeneity of (TbDy) -Fe (T) (T=Mn,Co,Al,Ti) System" J.of Alloys and Compounds. (発表予定). (1996)

    • Related Report
      1995 Annual Research Report
  • [Publications] Takateru Umeda: "Phase Selection During Growth of Peritectic System" 2nd Pacific Rim International Conference on Modeling of Castigand Solidification Processes. 133-145 (1995)

    • Related Report
      1995 Annual Research Report
  • [Publications] Takateru Umeda: "Phase Selection During Growth of Periectic Alloys" Actam Met.(掲載予定).

    • Related Report
      1995 Annual Research Report

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Published: 1995-04-01   Modified: 2016-04-21  

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