A Studyon Synthesis of High Purity <TEX>$beta$</TEX>-SiC Fine Particles from Ethyl Silicate(II) (Powder Properties, Reaction Type and Activation Energy)

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J. Korean Ceram. Soc. > Volume 26(2); 1989 > Article

Journal of the Korean Ceramic Society 1989;26(2): 195.

Ethyl Silicate를 이용한 고순도 $beta$-SiC미분말 합성에 관한 연구(II) (분말의 특성, 반응형식 및 활성화에너지)

최용식, 박금철¹

국립공업시험원 도자기시험소
¹한양대학교 공과대학 무기재료공학과

A Studyon Synthesis of High Purity $beta$-SiC Fine Particles from Ethyl Silicate(II) (Powder Properties, Reaction Type and Activation Energy)

ABSTRACT

The Silica-Carbon mixture was made with addition of carbon black in the composition which monodispersed spherical fine silica was formed by the hydrolysis of ethylsilicate, mole ratio of Carbon/Alkoxide was 3.1 and $beta$-SiC powder was synthesized by reacting this mixture at 1,350~1,50$0^{circ}C$ in Ar atmosphere. The results of this study are as follow : (1) The purity of synthesized $beta$-SiC powder was above 99.98% and it was in cubic modification with lattice constant of 4.3476$AA$. (2) The rate-controlling steps varied with the reaction temperature for the syntehsis of $beta$-SiC in this study ; nucleation and growth of $beta$-SiC at 1,350~1,40$0^{circ}C$, interfacial reaction at 1,45$0^{circ}C$ and diffusion described by Jander Equation at 1,50$0^{circ}C$. (3) When the rate-determining step was nucleation and growth, the activation energy was about 87.8kcal/mol.