서브마이크론/나노 크기의 SiC 비율변화에 따른 ZrB2-SiC 세라믹스의 열적, 기계적 특성 |
김성원, 채정민, 이성민, 오윤석, 김형태 |
한국세라믹기술원 엔지니어링세라믹센터 |
Thermal and Mechanical Properties of ZrB2-SiC Ceramics Fabricated by Hot Pressing with Change in Ratio of Submicron to Nano Size of SiC |
Seongwon Kim, Jung-Min Chae, Sung-Min Lee, Yoon-Suk Oh, Hyung-Tae Kim |
Engineering Ceramic Center, Korea Institute of Ceramic Engineering and Technology |
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ABSTRACT |
$ZrB_2$-SiC ceramics are fabricated via hot pressing with different ratios of submicron or nano-sized SiC in a $ZrB_2$-20 vol%SiC system, in order to examine the effect of the SiC size ratio on the microstructures and physical properties, such as thermal conductivity, hardness, and flexural strength, of $ZrB_2$-SiC ceramics. Five different $ZrB_2$-SiC ceramics ($ZrB_2$-20 vol%[(1-x)SiC + xnanoSiC] where x = 0.0, 0.2, 0.5, 0.8, 1.0) are prepared in this study. The mean SiC particle sizes in the sintered bodies are highly dependent on the ratio of nano-sized SiC. The thermal conductivities of the $ZrB_2$-SiC ceramics increase with the ratio of nano-sized SiC, which is consistent with the percolation behavior. In addition, the $ZrB_2$-SiC ceramics with smaller mean SiC particle sizes exhibit enhanced mechanical properties, such as hardness and flexural strength, which can be explained using the Hall-Petch relation. |
Key words:
$ZrB_2$-based ultra-high temperature ceramics (UHTCs), SiC size, Microstructure, Thermal properties, Mechanical properties |
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