Synthesis of Silicon Nitride from Ethyl Silicate(II) : Effect of Additive on the Nitridation of Silicon Nitride

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J. Korean Ceram. Soc. > Volume 25(5); 1988 > Article

Journal of the Korean Ceramic Society 1988;25(5): 561.

Ethyl Silicate로부터 Silicon Nitride의 합성(II) : 실화반응에서 첨가제의 영향

오일환, 박금철¹

대구공업전문대학 요업과
¹한양대학교 공과대학 무기재료공학과

Synthesis of Silicon Nitride from Ethyl Silicate(II) : Effect of Additive on the Nitridation of Silicon Nitride

ABSTRACT

Mixtures of very small amounts of additive, carbon and silica(about 0.46${mu}{textrm}{m}$) which synthesized by the hydrolysis of ethyl silicate, the molar ratio of SiO2/C was fixed to 1/10, was nitrided at 145$0^{circ}C$. It was considered that the optimum amount of additive to promote the nitridation reaction was below 2.0wt%. By the addition of additive, the nitridation reaction was promoted and formation of $beta$-Si3N4 was promoted at 145$0^{circ}C$ for 1hour, but, the nitridation reaction was decreased and the ratio of $alpha$/$beta$ of Si3N4, was increased at 145$0^{circ}C$ for 5 hours. The crystal phase was $alpha$ phase and the nitridation reaction was promoted and the particle size of silicon nitride was become smaller by the addition of $alpha$-Si3N4, but silicon nitride of whisker-like form was produced by the addition of transition elements. There was a difference in the lattice constants of $alpha$-Si3N4, but no difference in its of $beta$-Si3N4 according to kinds of added substance and reaction time.