Synthesis of <TEX>$beta$</TEX>-SiC Whiskers by the Carbothermal Reduction of Kaolin

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J. Korean Ceram. Soc. > Volume 35(12); 1998 > Article

Journal of the Korean Ceramic Society 1998;35(12): 1249.

카올린의 환원 열탄화법에 의한 베타 탄화규소 휘스커의 합성

오세정, 류종화, 조원승¹, 최상욱

인하대학교 무기재료공학과
¹인하대학교 무기재료공학

Synthesis of $beta$-SiC Whiskers by the Carbothermal Reduction of Kaolin

ABSTRACT

${beta}$-Silicon carbide(${beta}$-SiC) whiskers could be synthesized by the carbothermal reduction of kaolin at tem-peratures between 1400 and 1500$^{circ}C$. The whiskers were grown up to about 1150 of aspect ratio by VS mechanism (showing tapering tips) and to about 45 of that by VLS mechanism (showing round droplet tips) respectively. Hydrocarbon like methane in the reaction atmosphere promoted the formation of gaseous il-icon monoxide(SiO) from silicon dioxide(SiO2) and subsequently reacted with it to form whiskers. The for-mation of ${beta}$-SiC whiskers increased with increasing carbon content(to 30 wt%) and reaction temperatures. The max. yield of ${beta}$-SiC whiskers was 15% at 1500$^{circ}C$ under 20%CH4/80%H2.

Key words: Silicon carbide whisker, VLS mechanism, Silicon monoxide, Kaolin, Carbothermal reduction