1. SiC Ceramic-Bonded Carbon Fabricated With Si3N4 and Carbon Powders.
- Author
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Chen, Weiwu, Tojo, Tetsuro, and Miyamoto, Yoshinari
- Subjects
CERAMICS ,SINTERING ,TEMPERATURE ,THERMAL conductivity ,BENDING (Metalwork) ,CARBON ,SILICON carbide ,POWDERS - Abstract
New composites called ceramic-bonded carbon ( CBCs), consisting of a three-dimensional structure of carbon particles bonded with thin ceramic boundaries, were developed. To fabricate light and tough CBCs and to understand their reinforcing mechanism, Si
3 N4 and carbon powders (25:75 in volume ratio) were gelcasted and then sintered by spark plasma sintering at temperatures of 1700-1900°C. The ceramic boundary of SiC was formed in situ at above 1700°C by the reaction of Si3 N4 and C. The sintered CBCs showed a unique microstructure consisting of carbon particles and ceramic boundaries of 15 μm in size and 0.5-3 μm in thickness, respectively. With an increase in sintering temperature, physical bonding of ceramic grains to the carbon particles was enhanced as the grain growth of SiC increased. The SiC/ CBCs sintered at 1900°C were highly dense (97% theoretical density), lightweight (2.36 mg/m3 ), and had both relatively high bending strength and thermal conductivity (135 MPa and 140 W/mK, respectively). [ABSTRACT FROM AUTHOR]- Published
- 2012
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