| Project/Area Number |
03452104
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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 |
機械材料工学
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| Research Institution | Yamaguchi University |
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Principal Investigator |
HATANAKA Kenji Yamaguchi Univ., Dept. of Mechanical Engineering, Professor, 工学部, 教授 (60026193)
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| Co-Investigator(Kenkyū-buntansha) |
OGI Junji Yamaguchi Univ., Dept. of Mechanical Engineering, Research Associate, 工学部, 助手 (80223965)
FUJIMITSU Tatsuro Yamaguchi Univ., Dept. of Mechanical Engineering, Associate Professor, 工学部, 助教授 (70035062)
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| Project Period (FY) |
1991 – 1992
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| Project Status |
Completed (Fiscal Year 1992)
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| Budget Amount *help |
¥6,300,000 (Direct Cost: ¥6,300,000)
Fiscal Year 1992: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1991: ¥5,400,000 (Direct Cost: ¥5,400,000)
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| Keywords | Sintered Silicon Nitride Ceramics / High Temperature Tensile Test / Tensile Stress-Strain Response / Inelastic Deformation / Measurement of Tensile Displacement / Elastic-Plastic F.E.M / High Temperature Creep / High Temperature Fatigue / 常圧焼結窒化けん素セラミック |
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| Research Abstract |
The tensile tests and tensile creep tests were performed for the sintered silicon nitride ceramics at elevated temperatures. The four projections were machined in the gauge length of the specimen, and the displacement was measured between the two projections on one side of the specimen by means of the laser-beam-type extensometer. Furthermore, the new test system was developed for evaluating the fatigue properties of ceramics at elevated temperatures. Then push-pull fatigue tests were performed for the sintered silicon nitride ceramics in the temperature range from room temperature to 1200ﾟC. The results obtained are summarized as follows :
1. The tensile stress-strain relationship was markedly influenced by test temperature and displacement rate.
2. The nominal stress-strain relationships calculated from the measured load (P)-displacement(delta) relationships were corrected so that the p-delta curve calculated using the elastic-plastic F.E.M agreed with the measured one. The corrected stress-strain relationship seems to give the intrinsic relationship of sintered silicon nitride ceramics at elevated temperatures.
3. The creep curves of sintered silicon nitride ceramics exhibited the transient creep period, being followed by the steady creep period.
4. According to the relationships between the minimum creep strain rate and nominal stress plotted in double logarithmic scales, the data could be fitted by two straight lines, and their slopes are larger in the higher stress region than in the lower stress region.
5. The relationships between stress amplitude and number of cycles to failure showed the shape of a so called S-N curve. The slope of S-N curve, however, had a tendency to decrease with increase in test temperature.
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