| Project/Area Number |
17360339
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Structural/Functional materials
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| Research Institution | Nagoya Institute of Technology |
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Principal Investigator |
DOI Minoru Nagoya Institute of Technology, Department of Materials Science and Engineering, Professor (60135308)
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| Co-Investigator(Kenkyū-buntansha) |
KOZAKAI Takao Nagoya Institute of Technolagy, Department of Materials Sciense and Engineefing, Associate Professor (80110253)
MORITANI Tomokazu Nagoya Institute of Technology, Department of Materials Science and Engineering, Research Associate (50362322)
ENOMOTO Yoshihisa Nagoya Institute of Technology, Department of Environmental Technology and Urban Planning, Associate Professor (70194008)
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| Project Period (FY) |
2005 – 2007
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| Project Status |
Completed (Fiscal Year 2007)
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| Budget Amount *help |
¥11,740,000 (Direct Cost: ¥10,900,000、Indirect Cost: ¥840,000)
Fiscal Year 2007: ¥3,640,000 (Direct Cost: ¥2,800,000、Indirect Cost: ¥840,000)
Fiscal Year 2006: ¥3,100,000 (Direct Cost: ¥3,100,000)
Fiscal Year 2005: ¥5,000,000 (Direct Cost: ¥5,000,000)
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| Keywords | structural materials / heat resisting alloy / microstructure / phase transformation / precipitation / elasticity effect / 相変体 |
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| Research Abstract |
The formation and the stability of two-phase microstructures in some Ni-base and Fe-base alloys were investigated by means of transmission electron microscopy observations. Main results obtained are as follows.
1.Phase-separation behaviours which can be seen in the course of formation and evolution of γ+γ' (A1+L12)two-phase microstructure in Ni-Al-Ti ternary alloys exhibit various aspects depending on the alloy compositions, heat-treatment conditions, etc, as follows.
(1) Phase-separation of γ solid solution takes place to form γ precipitate particles in y matrix.
(2) Phase-separation of γ' solid solution (γ' intermetallics)takes place to form γ precipitate particles in γ' matrix.
(3)Phase-separation of γ' precipitates, which appear due to the phase-separation of γ solid solution, takes place to form γ particles in each γ' precipitate.
2.The phenomenon that the phase-separation of precipitate particles takes place to form new particles in each precipitate can be seen not only in γ+γ' microstructure in Ni-base alloys but also in other two-phase microstructures such as A2-FD03 in Fe-base alloys.
3.In the course of the phase-separation of precipitate particles, the size of each precipitate does not change practically.
4.TEM tomography can successfully be applied to observe the three-dimensional morphology of precipitates in a Ni-Al-Ti alloy.
5.Utilizing the phase-separation phenomenon of two-phase microstructure(i.e. the phase separation of already existing precipitates)is important and useful to obtain a stable two-phase microstructure desirable to heat resisting alloys.
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