| Project/Area Number |
12650702
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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 |
Structural/Functional materials
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| Research Institution | Chiba Institute of Technology |
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Principal Investigator |
FUNAMI Kunio Chiba Inst. Of Technology, Faculty of Engineering, Professor, 工学部, 教授 (90010876)
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| Co-Investigator(Kenkyū-buntansha) |
清水 秀治 千葉工業大学, 工学部, 助手 (30178983)
鈴木 浩治 千葉工業大学, 工学部, 講師 (70322427)
河野 紀雄 千葉工業大学, 工学部, 教授 (80083822)
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| Project Period (FY) |
2000 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥3,400,000 (Direct Cost: ¥3,400,000)
Fiscal Year 2001: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 2000: ¥2,200,000 (Direct Cost: ¥2,200,000)
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| Keywords | Sociology of Organizations / Organizational Ecology / New institutionalism / Population Ecology / Community Ecology / Network / Australia / Organizational Evolution / 疲労 / 腐食 / 加工ひずみ法 / 脱水素処理 |
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| Research Abstract |
The grain refinement is noticed, as method to enhance the strength of materials and to be appeared the superplasticity behavior. The subject of this study has shown that, in 5083AI (AI-Mg) alloy, this microstructure with fine grain size can be achieved by imposing extremely large plastic strains during work processing using characteristic properties such as hydrogen absorption and dehydrogenation at high temperature. Hydride precipitations MgH_2 obtained in this treatment were more useful to develop the high-density dislocation structure in alloy as dislocation pileup sources.
The following results of this study were obtained :
2001〜2001
1 : Hydrogenation treatment was carried out in 773K for 14. 4ks and in hydrogen atmosphere under 0. 4MPa. The hydrogenated samples were carried out heavy cold rolling with the 90% reduction ratio An existence of hydrides was determined by an X-ray diffraction analysis and TEM observation using tritium technique An induced hydrogen content was about 107×10
… More
^2 mass%. Then, to obtain the fine grain sized material, heat treatment was performed to do rapid recrystallization in salt bath. The materials were finally heated at 523K in vacuum (0. 1Pa) for dehydrogenation for 30hr. The residual hydrogen content was 0. 9×10^2 mass%. The hydrogenated samples indicates wavy deformation traces to be prevented easy deformation and shows more fine grain structure (2. 5 u m). Yield strength and tensile strength increased more than 1. 5times in comparison with that of non-hydrogenated specimen.
2 : An existence of hydrides was determined by an x-ray diffraction analysis and TEM observation using tritium technique. The grain size is finer with induced hydrogen content.
2001〜2002
1 : For superplasticity behavior of hydrogenated specimen, elongation was about 300% at 625K and 5×10^3 s^1 strain rate. The fatigue strength of these samples was 1. 8times higher than that of non-hydrogenated samples. However, in corrosion test, these samples did not indicate remarkable improvement. Less
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