2004 Fiscal Year Final Research Report Summary
Observation of lattice defects, deformation behavior in duplex alloys and evaluation of their lifetime using magnetic properties.
| Project/Area Number |
14205105
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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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 | Osaka University |
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Principal Investigator |
UMAKOSHI Yukichi Osaka University, Graduate School of Engineering, Professor, 大学院・工学研究科, 教授 (00029216)
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| Co-Investigator(Kenkyū-buntansha) |
NAKANO Takayoshi Osaka University, Graduate School of Engineering, Associate Professor, 大学院・工学研究科, 助教授 (30243182)
YASUDA Hiroyuki Osaka University, Center of Ultra high Voltage Electronmicroscope, Associate Professor, 超高圧電子顕微鏡センター, 助教授 (60294021)
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| Project Period (FY) |
2002 – 2004
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| Keywords | Spontaneous magnetization / coercive force / paramagnetism / fatigue / deformation / superparamagnetism / material reliability / superalloy |
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| Research Abstract |
Numerous dislocations and planar faults in metallic materials are introduced during fatigue deformation. Stress concentration near high density of lattice defects initiates a microcrack and finally fracture occurs. To understand the deformation mechanism and evaluate the reliability observation of lattice defects such as dislocations is necessary.. In general, the observation of lattice defects is performed using electron microscope. However, it is very difficult to obtain exact information about nature of dislocations due to high residual stress near the dislocations. It is known that magnetic properties are very sensitive to lattice defects in ferromagnetic materials. The lattice defects have been observed by magnetic technique. In this work, deformation behavior of FeAl, Fe_3Al and Ni_3(Al,Ti) containing small γ precipitates single crystals were prepared and their fatigue behavior was examined by magnetic technique. High-field susceptibility and spontaneous magnetization in FeAl and Fe_3Al were influenced by deformation. Type of dislocation and planar faults were determined by anisotropy of high field susceptibility. Lifetime of FeAl can be estimated by monitoring spontaneous magnetization because the spontaneos magnetization rapidly increases just before fracture during fatigue.
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Research Products
(24 results)
