1986 Fiscal Year Final Research Report Summary
On The Microstructures and Mechanical Properties of The Extrudates of Ribbon-Shaped Rapidly-Solidified Aluminum Alloys
| Project/Area Number |
60550486
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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 |
金属加工(含鋳造)
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| Research Institution | Nagoya Institute of Technology |
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Principal Investigator |
OHASI Teruo Faculty of Engineering, Nagoya Inst. Tech., Prof., 工学部, 教授 (70024263)
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| Co-Investigator(Kenkyū-buntansha) |
MIWA Kenji Faculty of Engineering, Nagoya Inst. Tech., Assistant, 工学部, 助手 (30110266)
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| Project Period (FY) |
1985 – 1986
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| Keywords | Rapid Solidification / Al-Transition Metal Alloy / Young's Modulus Quasicrystal / Consolidation of RSR / 析出 / コンソリデイション / ヤング率 |
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| Research Abstract |
The single-roll rapid solidification apparatus which has been manufactured by this found can give a cooling rate of <10^4> - <10^5> k/sec . The microstructures of rapidly-solidified aluminum-transition metal alloys are composed of very fine dendritic cells and/or plain polycrystals, having their sizes of the order of 0.01 - 0.1 <micro> m. The increasesin solute content promote the segregation of the secondary phases at the cell boundaries. Especially in Al-Mn-Zr or Al-Mn-Si ternary alloys, a quasicrystalline phase having icosahedral or 5-fold symetry appears in these boundaries. A new interesting fact that the above quasicrystalline phases can also precipitate in the supersaturated solid solutions obtained by rapid solidification has been found in this project.
The consolidation of rapidly-solidifed ribbons by means of vacuum hot press and hot extrusion processes gives the microstructures composed of precipitates finely dispersed in the fine polycrystal grains of the matrix.
Young's moduli of the Al-Mn and Al-Zr extruded alloys were measured by a vibrational resonance method. The moduli increased linearly with the increase in the volume of dispersoids and attained to 88000 kg/ <mm^2> at about 30 vol.% <Al_6> Mn dispersoid. Also Young's modulus increment per unit vol.% dispersoid were estimated to be 69.7 and 54.4 kg/ <mm^2> for Al-Mn and Al-Zr extruded alloys, respectively.
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