Effect of Initial Alpha-SiC Content on Thermal Conductivity of Silicon Carbide Ceramics

Abstract:

By using α-and/or β-SiC powders, the effects of initial α-phase content on the microstructure and thermal properties of the SiC ceramics sintered with Y₂O₃ and Sc₂O₃ were investigated. When α-SiC powder was used, the microstructure consisted of large equiaxed grains and small equiaxed grains. The average grain size decreased with increasing α-SiC content in the starting composition. The thermal conductivity decreased with increasing α-SiC content in the starting composition. Such results suggest that the grain growth of SiC ceramics is beneficial in increasing the thermal conductivity of liquid-phase sintered SiC ceramics. The thermal conductivity of SiC ceramics processed from a 90% β-SiC-10% α-SiC powder mixture was 159 W/m∙K at room temperature.

• Periodical: Key Engineering Materials (Volume 616)
• Pages: 23-26
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.616.23
• Online since: June 2014
• Authors: Kwang Young Lim*, Tae Young Cho, Young Wook Kim, Seung Jae Lee
• Keywords: Hot-Pressing, Microstructure, Silicon Carbide (SiC), Thermal Conductivity

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