| Project/Area Number |
61490003
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
広領域
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| Research Institution | TOHOKU UNIVERSITY |
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Principal Investigator |
INOUE Akihisa Institute for Materials Research, Tohoku University, 金属材料研究所, 助教授 (10108566)
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| Co-Investigator(Kenkyū-buntansha) |
MATSUZAKI Kunio Institute for Materials Research, Tohoku University, 金属材料研究所, 助手 (20181711)
KIMURA Hisamichi Institute for Materials Research, Tohoku University, 金属材料研究所, 助手 (00161571)
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| Project Period (FY) |
1986 – 1988
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| Project Status |
Completed (Fiscal Year 1988)
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| Budget Amount *help |
¥5,700,000 (Direct Cost: ¥5,700,000)
Fiscal Year 1988: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1987: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1986: ¥4,700,000 (Direct Cost: ¥4,700,000)
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| Keywords | amorphous powder / high-pressure gas atomization / press-sintering / amorphous bulk / two-stage quenching / supercooled liquid / liquid quenching / 過冷却液体急冷法 / 過冷却微小液的 / アモルファス形成範囲 / 構造緩和量 / アモルファス合金粉末 / フレーク形状粉末 / 2段液体急冷法 / 微小過冷液滴堆積法 / 厚板状アモルファスリボン材 / アモルファスバルク材 / 高比強度材 / 超音波超高圧ガス噴霧 / 合金粉末 / 非平衡相粉末 / 真球粉末 / 塊状材 / 耐熱硬さ / 耐磨耗性 |
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| Research Abstract |
A new liquid quenching equipment by utilizing an ultrasonic and high-pressure gas atomization method was designed and constructed with the aim of developing a method which can produce effectively amorphous spherical powders. Many factors of producing amorphous powders in Fe- and Co-based alloy systems were investigated and the atomization condition of producing the amorphous powders was established. Subsequently, the consolidation of the amorphous powders was tried by press-sintering at elevated temperatures. As a result, it was clarified that the consolidation is difficult for the spherical powders and the mixing of flaky powders to the spherical powders is very effective for the formation of amorphous bulks. From this information, the atomization equipment was modified so as to produce flaky powders as well as spherical powders. In the modification, the rotator was set up at the position just below the gas atomization nozzle and small atomized liquid droplets were flattened by the rotator, resulting in the formation of flaky powders with a small thickness of 1 to 3 m. Furthermore, the heat of relaxation was much larger than that for the melt-spun ribbons, indicating the achievement of much higher cooling velocities by the two-stage quenching method. The increase of cooling velocity is probably due to the subsequent cooling of super-cooled liquid droplets produced by gas atomization. In addition, the two-stage quenching technique was found to bring about the glass formation in new alloy systems such as Fe-C binary alloys and a remarkable extension of glass formation range in glass-forming alloy systems. These features of the newly developed two-stage quenching technique consisting of ultrasonic and high-pressure gas atomization followed by impact flattening of the supercooled liquid droplets are concluded to be attractive enough to confirm further progress of the two-stage quenching technique and the resulting nonequilibrium alloy powders.
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