1991 Fiscal Year Final Research Report Summary
Fundamental Study on Usefulness of Titanium Castings in Prosthetic Dentistry
| Project/Area Number |
01571072
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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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 | Meikai University School of Dentistry |
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Principal Investigator |
NAGAYAMA Katsuya Meikai univ., Sch. of Dent., Assis. Prof., 歯学部, 講師 (40105630)
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| Project Period (FY) |
1989 – 1991
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| Keywords | Titanium casting / Castability / Flexure property / Mechanical property / Mold temperature |
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| Research Abstract |
The investigate influence of the mold temperature, sprueing and types of investment on castability and mechanical properties of the titanium castings were examined. The castability was found to be good at various mold temperature and by the use of sprue which has more than 2.1mm in diameter. But the higher the mold temperature during casting, the greater the adhesive phenomenon between titanium surface and the investment. From the E P M A observation of the surface layer on the titanium castings, an Si-rich layer whose thickness increased considerably with increasing temperature was observed. The Vickers hardness in the surface layer was greater than that in the inner part. At a higher mold temperature during casting the thickness of the high Vickers hardness layer was increased. There was a relationship between the Vickers hardness number and the thickness of Si rich layer.
In the tensile strength test of titanium castings, elongation values decreased and tensile strength values increased with the rise in mold temperature.
In the flexure test, elastic modulus of titanium castings was approximate values compared with Type 4 gold alloy castings, but smaller values than that of Co-Cr alloy castings. The turning point stress, 0.03 % proof stress and 0.2 % proof stress values of titanium castings were smaller than that of Type 4 gold alloy (hardened) and Co-Cr alloy castings. As regards the influence of the mold temperature on flexure properties, there was a significant difference in elastic modulus between the mold temperature of room temperature and 900ﾟC. And 0.2 % proof stress values increased with the rise in mold temperature.
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