| Project/Area Number |
60480422
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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 |
補綴理工系歯学
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| Research Institution | Niigata University |
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Principal Investigator |
SHIOKAWA Nobuhiro Chief Professor, School of Dent., Niigata Univ., 歯学部, 教授 (90018408)
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| Co-Investigator(Kenkyū-buntansha) |
OKAWA Seigo Assistant, School of Dent., Niigata Univ., 歯学部, 助手 (80143791)
WATANABE Kouichi Assistant, School of Dent., Niigata Univ., 歯学部, 助手 (20018766)
MIYAKAWA Osamu Associate Professor, School of Dent., Niigata Univ., 歯学部, 助教授 (40018429)
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| Project Period (FY) |
1985 – 1986
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| Project Status |
Completed (Fiscal Year 1986)
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| Budget Amount *help |
¥4,800,000 (Direct Cost: ¥4,800,000)
Fiscal Year 1986: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1985: ¥4,200,000 (Direct Cost: ¥4,200,000)
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| Keywords | Grinding Performance / Cubic Boron Nitride / Diamond / Electrodeposition / Vitrified Bond / Alumina / Acoustic Emission / 振れ |
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| Research Abstract |
The mechanism governing dental grinding was studied by testing of grinding performance, analyzing acoustic emission(AE) and vibration during the grinding process, and observing grinding chips and wheel surfaces. The results obtained are as follows: 1. AE signal detected accurately wheel-work contact and sparkout. AE analysis revealed that the greater the run-out of wheel, the greater was the tendency for intermittent grinding with a period corresponding to the rotational speed of wheel. 2. Much remained unknown in the interpretation of AE spectrum. Application of AE to dental grinding problem requires collection of fundamental AE data. 3. The diamond electrodeposited wheel yielded most superior performance in the initial stage, but rather inferior performance in the latter. This is due neither to wheel loading, nor to attrition or dislodging of the grain, but to a behavior of the Ni-P plating alloy used for holding the grain together. 4. Superior performance of the CBN electrodeposited wheel, being much lower compared with the initial performance of the diamond wheel, continued steadily. 5. The analysis of work- and handpiece- vibration and mandrel whirling revealed the difference of grinding mechanism between the vitrified bond wheels and the electrodeposited wheels. 6. As for the vitrified bond wheels, it is important to use a wheel with a constituent element suitable for the grinding material and to grind so that self dressing may be active. For Co-Cr alloys, an alumina wheel with such an appropriate element was suggested to be capable of yielding superior result comparable to the CBN wheel. 7. Systematic test of various wheels with different grain sizes, grades, and structures needs to be made for determining the constituent element suitable for each of such difficult-to-machine materials as Ni-Cr and Ti- alloys.
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