| Project/Area Number |
16560635
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Material processing/treatments
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| Research Institution | The University of Tokushima |
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Principal Investigator |
YOSHIDA Kenichi The University of Tokushima, Faculty of Engineering, Professor, 工学部, 教授 (50200986)
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| Co-Investigator(Kenkyū-buntansha) |
NISHINO Hideo The University of Tokushima, Faculty of Engineering, Associate Professor, 工学部, 助教授 (50316890)
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| Project Period (FY) |
2004 – 2005
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| Project Status |
Completed (Fiscal Year 2005)
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| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2005: ¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 2004: ¥2,100,000 (Direct Cost: ¥2,100,000)
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| Keywords | Acoustic Emission / Gas Leak / Aluminum Alloys / Hydrogen Micro-Print Method / Hydrogen Embrittlement / アコースティック・エミッション(AE) / 疲労損傷 / AE波形解析 |
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| Research Abstract |
A consistent measuring procedure to sequentially detect the generation and growth of micro-cracks due to hydrogen embrittlement and macro-cracks with gas leak by acoustic emission (AE) method has been investigated using a steel for pipe material and aluminum alloys for hydrogen cylinder (5000 and 6000 series alloys). New knowledge and results obtained are as follows :
1.Hydrogen damages were revealed to concentrate along slip lines and grain boundaries by hydrogen microprint method. Grain boundaries easy to make these damages were identified using electron back scattering pattern (EBSP) analysis. The generation and growth of the micro-cracks due to hydrogen damages was closely related to the detected AE signals.
2.New method was proposed to contract the characteristics of the AE waveforms because the elastic wave propagating in finite body shows velocity dispersion and mode transform. It was recognized that the analytical method was useful to analyze the AE waveforms detected during plastic deformation and micro-cracking due to the hydrogen damage.
3.Characteristic AE waveforms could be obtained during the gas leak from artificial pinholes similar to the macro-cracks due to hydrogen damage. Application to hydro-dynamical noise evaluation was made clear to be possible using the peak frequency of the AE waveforms
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