1990 Fiscal Year Final Research Report Summary
Development of Anisotropic Misch-Metal-Fe-B Melt-Spun Magnets and its Application to Plastic Magnets
| Project/Area Number |
01850063
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| Research Category |
Grant-in-Aid for Developmental Scientific Research (B).
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| Allocation Type | Single-year Grants |
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| Research Field |
電子材料工学
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| Research Institution | Kyushu Institute of Technology |
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Principal Investigator |
YAMASAKI Jiro Kyushu Inst. Tech., Dept. ELECTRICAL Engng.,, 工学部, 教授 (40108668)
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| Co-Investigator(Kenkyū-buntansha) |
OHMORI Kenji Sumitomo Metal Mining Co. Central Research Lab., 中央研究所, 主任研究員
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| Project Period (FY) |
1989 – 1990
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| Keywords | Rare-earth Magnets / Anisotropy / Orientation / Plastic Magnets / Melt-spun magnets / Misch metal |
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| Research Abstract |
It has been recognized that development of application field of misch metal (MM) to electrical materials is of great importance with respect to effective consumption of natural resources. We developed the MM-Fe-B isotropic melt-spun magnets with the energy product more than 8MGOe. Its cost-performance (measured with cost per energy product) is comparable to that of Ba ferrite magnets. In this research program, effort was made to develop the c-axis orientation technique for higher cost-performance permanent magnets.
(1) Among various parameters of melt-quenching technique, the temperature of the melt when ejected onto the rotating wheel is the most important one affecting the c-axis orientation of the R2Fe14B tetragonal compounds. When the temperature is kept 200 degree higher than the melting point, mostly perfect c-axis orientation within 3 degree dispersion was available on both the free and wheel surfaces.
(2) The thickness of orientated layer is 15 mu m on the free surface and 5 mu m on the wheel surface. The intermediate layer has the less oriented structure.
(3) Addition of fourth elements such as Ta and Zr improve the c-axis orientation. The former and former elements are effective on the orientation at free and wheel surfaces, respectively.
(4) Accompanied by the c-axis orientation, grain size tends to be coarse. To obtain the high coercivity, control of the materials precipitaing at the grain boundary seems necessary.
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