The Effects of Surface Finish and Grain Size on the Strength of Sintered SiC

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J. Korean Ceram. Soc. > Volume 21(1); 1984 > Article

Journal of the Korean Ceramic Society 1984;21(1): 27.

소결탄화규소의 표면처리 및 비정상 성장입자가 강도에 미치는 영향

유영혁, 김영욱, 이준근¹, 김종희

한국과학기술원 재료공학부
¹한국과학기술원 재료공학

The Effects of Surface Finish and Grain Size on the Strength of Sintered SiC

ABSTRACT

During the last decade there have been many studies on the new ceramics especially engineering ceramics. Sintered silicon carbide is one of the main materials in engineering ceramics. This study shows the effects of surface treatment and microstructure especially the abnormal grain growth on the strength of sintered SiC. Surface of sintered SiC and treated with 400, 800 and 1200 grit diamond wheel. Grain growth is introduced by increasing the sintering times at 205$0^{circ}C$. The $beta$longrightarrow$alpha$ transformation occurs during the sintering of $beta$-starting materials and is often accompanied by abnormal grain growth. The overall strength distribution are estimated using the Weibull statistics. The results show that the strength of sintered SiC is limited by extrinsic surface flaws in normal-sintered specimens. And it is sound that the finer the surface finishing and the grain size the higher the strength results. But the strength of abnormal sintering specimens is limited by the abnormally-grown large tabular grains. The Weibull modulus increases with the decreasing grain size and the decreasing grit size of grinding.