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Thermal behaviour of casting investment during setting
1Department of Dental Materials, Hiroshima University, School of Dentistry, Japan.
Journal of Oral Rehabilitation
|May 1, 1995
Summary
This study investigated silica-sol liquids for investment powders. Mixed silica-sol investment showed superior setting behavior and heat compared to gypsum-bonded investment.
Area of Science:
- Materials Science
- Chemical Engineering
Background:
- Silica-sol liquids are used in investment powders for casting.
- Understanding their thermal properties and setting behavior is crucial for optimizing casting processes.
Purpose of the Study:
- To analyze the thermal reactions of silica-sol liquids using Differential Thermal Analysis (DTA).
- To evaluate the setting behavior of mixed silica-sol investment powders with Differential Scanning Calorimetry (DSC).
Main Methods:
- Differential Thermal Analysis (DTA) to study silica-sol liquid thermal reactions.
- Differential Scanning Calorimetry (DSC) to assess the setting behavior of investment powder mixtures.
Main Results:
- DTA revealed vaporization around 100°C and combustion between 200-300°C for silica-sol liquids.
- DSC showed that mixed silica-sol investment exhibits a more pronounced exotherm, indicating greater peak time, setting time, and heat compared to gypsum-bonded investment.
Conclusions:
- Silica-sol liquids possess distinct thermal reaction profiles.
- Silica-sol bonded investments offer enhanced setting characteristics over traditional gypsum-bonded investments, suggesting potential for improved casting outcomes.
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