2000 Fiscal Year Final Research Report Summary
Development of microstracture on increasing fatigue toughness of dental Ag-Pd-Cu-Au alloy
| Project/Area Number |
11671965
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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 |
補綴理工系歯学
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| Research Institution | Aichi-Gakuin University |
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Principal Investigator |
FUKUI Hisao School of Dentistry, Aichi-Gakuin University Associateprofessor, 歯学部, 助教授 (50090147)
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| Project Period (FY) |
1999 – 2000
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| Keywords | Ag-Pd-Cu-Au alloy / microstracture / fracture toughness / Fatigue |
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| Research Abstract |
A fatigue test was carried out on heat-treated dental Ag-Pd-Cu-Au alloys in air. The effect of microstracture on fatigue characteristics was investigated. In the water quenched alloys, the fatigue strength increasing solutionizing temperature in the low-cycle fatigue region. While the fatigue strength decreased with increasing solutionizing temperature in the high-cycle fatigue region.
In aged alloys, the fatigue strength increased due to precipitation strengthening caused by the precipitation of B phase in the low-cycle fatigue region, while the fatigue strength markedly decreased due to the precipitated B phase, which let to a fracture site in the high-cycle fatigue regions.
The fracture touness of Ag-Pd-Cu-Au alloy increased with the increasing diameter of precipitated B phase in under aged conditions when volume fraction of precipitated B phase is constant. The fracture toughness increases with increasing width of slip area observed on the side surface of the specimen. The fracture toughness increased with the degree of crack deflection.
The fatigue strength of alloy with a large volume fraction of al phase was excellent due to the work hardening of a1 phase in the high-cycle fatigue region. However, the volume fraction of the B phase should be taken into account in order to improve the absolute value of fatigue strength.
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