Microstructures and Thermal Properties of Diamond/Ag-Ti Composites Fabricated by Pressureless Liquid Phase Sintering
博士 === 國立清華大學 === 材料科學工程學系 === 102 === In this study, Ti addition into matrix to improve the wettability between the diamond and Ag. Diamond/Ag-Ti composites were fabricated by a low-cost vacuum liquid sintering technique. The effects of Ti addition on the thermal properties of the composites were s...
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| Format: | Others |
| Language: | en_US |
| Published: |
2014
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| Online Access: | http://ndltd.ncl.edu.tw/handle/46654002822739246659 |
| Summary: | 博士 === 國立清華大學 === 材料科學工程學系 === 102 === In this study, Ti addition into matrix to improve the wettability between the diamond and Ag. Diamond/Ag-Ti composites were fabricated by a low-cost vacuum liquid sintering technique. The effects of Ti addition on the thermal properties of the composites were studied. The results indicate that the optimal quantity of added Ti is 3 at.%. Adding less than 3 at.% Ti resulted in poor wettability, while adding more than 3 at.% Ti resulted in excessive formation of TiC between diamond and Ag . Both reduced thermal conductivity. A composite comprising 60 vol.% diamond/Ag-3at.%Ti resulted in a maximum thermal conductivity of 836 W/mK with a coefficient of thermal expansion of 5.6 ppm/K. Furthermore, the holding time effect on thermal properties of the 60 vol.% diamond/Ag-3at.%Ti composites also were investigated. The relative density and thermal conductivity decreased with the holding time increased from 60 min to 180 min. The diamond/Ag-3 at.% Ti composite can be applied as a promising heat spreader with high reliability because it has high TC and also its coefficient of thermal expansion can be tailored for a specific semiconductor material for electronic device applications. This low-cost vacuum liquid sintering process with active Ti addition is a promising technique to fabricate high thermal conductivity diamond/Ag composites.
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