1988 Fiscal Year Final Research Report Summary
Fatigue of hard and bittle materials
| Project/Area Number |
62460198
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
溶接工学
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| Research Institution | Nagoya University |
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Principal Investigator |
OTSUKA Akio Nagoya University, 工学部, 教授 (60022993)
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| Co-Investigator(Kenkyū-buntansha) |
TOHGO Kei-ichiro Nagoya University, 工学部, 助手 (10155492)
MORI Kaname Nagoya University, 工学部, 助手 (70023207)
MIYATA Takashi Nagoya University, 工学部, 助教授 (20023228)
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| Project Period (FY) |
1987 – 1988
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| Keywords | Tension-compression fatigue / WC-Co hardmetal / Silicon nitride / Ceramics Static fatigue / Cyclic fatigue / 繰返し疲労 / 応力比 |
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| Research Abstract |
Tension-compression fatigue tests were made on two kinds of hard materials,WC-Co hardmetal and silicon nitride. It has been found that these materials show completely different fatigue characteristics from those of metals. The fatigue limits of WC-Co hardmetals are determined by the maximum stress and that take almost s constant value, regardless of Co-content and WC grain size. Fatigue tests on silicon nitride have shown, on the effects of stress ratio and Co contents, that the fatigue life will be shorter with larger stress rations and with smaller stress ranges. The reason why these hard materials show the opposite tendency to metals, will be that the fatigue properties of these hard meterials depend not only on mechanical properties but also on various physical and chemical properties, while the fatigue characteristics of metals depend solely on mechanical properties. It has been shown that the newly developed apparatus is very suited to the fatigue tests on hsrdmaterials because of its excellent accuracy and capability of tension-compression fatigue tests at arbitraly stress ratios.
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