| Project/Area Number |
63550526
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
金属材料(含表面処理・腐食防食)
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| Research Institution | Tohoku University |
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Principal Investigator |
MATSUZAKI Kunio Tohoku University Institute for Materials Research, Researcher, 金属材料研究所, 助手 (20181711)
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| Co-Investigator(Kenkyū-buntansha) |
INOUE Akihisa Tohoku University Institute for Materials Research, Professor, 金属材料研究所, 教授 (10108566)
MASUMOTO Tsuyoshi Tohoku University Institute for Materials Research, Professor, 金属材料研究所, 教授 (20005854)
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| Project Period (FY) |
1988 – 1990
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| Project Status |
Completed (Fiscal Year 1990)
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| Budget Amount *help |
¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1990: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1989: ¥500,000 (Direct Cost: ¥500,000)
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| Keywords | Mechanical Blending / Mechanical Alloying / High Energy Ball Mill / Immiscible Alloy / Dispersion / メタニカルブレンド法 / 高エネルギ-ボ-ルミル / 高エネルギー型ボールミル |
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| Research Abstract |
The composite materials with homogeneously mixed structure were prepared in immiscible (Si, SiO_2)-(Pb, Pb_<60>Bi_<40>) systems were prepared by a combined technique of mechanical blending (MB) and hotpressing. The hot-pressed compact of the mechanical blended Si80Pb20 powder consists of show a duplex structure in which Pb particles finely dispersed in Si matrix. The hot pressing of the MB (SiO_2)_<80>(Pb_<0.6>Bi_<0.4>)_<20> powder at the temperature above the melting point of Pb_<60>Bi_<40> caused a layered structure. These compacts exhibit extremely high electrical resistivities in the ranging from 2 to 12 mu OMEGAm and superconductivity at temperatures below 9K. The H_<c2> at 4.2 K is as high as 1.7 to 1.8 T for the (Si, SiO_2)-Pb composites and 2.7 to 3.2 T for the (Si, SiO_2-Pb_<0.6>Bi_<0.4> composites. These values are much higher than those of pure Pb metal or Pb_<0.6>Bi_<0.4> alloy and the enhancement of H_<c2> is due to the unique mixed structure caused by hot pressing of mechanical blended powders.
This synthesis method is also applied to the preparation of the precursor for high Tc superconducting oxides. Immiscible Y-Ba-Cu and Bi-Sr-Ca-Cu alloys were mechanical blended into fine powders with a homogeneous fcc structure or a mixed duplex structure and the subsequent treatments and oxidation of the MB powders caused the high Tc superconductors with Tc of 90 K for the Y-Ba-Cu system and 110 K for the Bi-Sr-Ca-Cu system.
It is thus summarized that the mechanical blending is a useful method for the formation of fine powders with homogeneously dispersed structure in immiscible alloy systems and the composite materials made from their powders exhibit the unique functional properties.
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