2003 Fiscal Year Final Research Report Summary
Evaluation of Reliability in Harmonic Material System
| Project/Area Number |
11221205
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| Research Category |
Grant-in-Aid for Scientific Research on Priority Areas (B)
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| Allocation Type | Single-year Grants |
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| Review Section |
Science and Engineering
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| Research Institution | The University of Tokyo |
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Principal Investigator |
ENOKI Manabu Graduate School of Engineering, Associate Professor, 大学院・工学系研究科, 助教授 (70201960)
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| Co-Investigator(Kenkyū-buntansha) |
TAKEDA Nobuo Graduate School of Frontier Sciences, Professor, 大学院・新領域創成科学研究科, 教授 (10171646)
MORI Hisashi Railway Technical Research Institute, Materials Technology group, Researcher, 材料技術研究部, 研究員
KISHI Teruo National Institute for Materials Science, President (Researcher), 理事長(研究職)
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| Project Period (FY) |
1999 – 2001
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| Keywords | Laser interferometer / Acoustic emission / Non-destructive evaluation / Intermetallics / Layered materials / Self-toughening |
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| Research Abstract |
High performance is recently requested for materials, and also smart materials system which combine materials and structure has been developed. Novel approach for materials design which is different from the conventional one is expected. In these materials a new method to ensure a reliability of materials or a design of materials and structure for easy screening becomes important problems. In this research a novel non-contact nondestructive evaluation method was investigated based on the new approach of materials harmonic design, and also layered materials consist of metal and intermetallic component was developed because these materials demonstrates excellent crack prorogation resistance. Thermal cycle tests of alumina/SUS304 steel coatings was employed and acoustic emission waveforms due to microfracture during tests was successfully detected by laser AE system. The development of laser interferometer with high sensitivity is requested for the detection and analysis of small microfracture. We developed the laser AE system for improvement of the sensitivity and reduced the noise components by newly developed demodulator. The noise of the system was also improve by the focused detection points and averaging signals. The system finally enabled the measurement of AE with high signal/noise ratio. Processing conditions for Ti/Ti-Al layered materials were investigated, and mechanical properties and crack propagation process were analyzed. Also Ni/Ni-Al layered materials with thin metal layer was investigated. Heat treatment of Ni layer was tried to improve the ductility of materials and crack propagation resistance. The mechanisms of fabrication of intermetallic phase and the effect of residual stress on fracture toughness were also studied and finally a guide for materials design was obtained.
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