Synthesis of Powder of the System Si-Al-O-N from Alkoxides I. Synthesis of Si3N4 and <TEX>$beta$</TEX>-Sialon Ultrafine Powders from Alkoxides

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J. Korean Ceram. Soc. > Volume 24(1); 1987 > Article

Journal of the Korean Ceramic Society 1987;24(1): 23.

알콕사이드로부터 Si-Al-O-N계 분말합성 I. 알콕사이드로부터 Si3N4와 $beta$-Sialon 초미분말 합성

이홍림, 유영창

연세대학교 공과대학 요업공학과

Synthesis of Powder of the System Si-Al-O-N from Alkoxides I. Synthesis of Si3N4 and $beta$-Sialon Ultrafine Powders from Alkoxides

ABSTRACT

Synthesis of high purity ultrafine Si3N4 and ${beta}$-Sialon powders was investigated via the simultaneous reduction and nitriding of amorphous SiO2, SiO2-Al2O3 system prepaerd by hydrolysis of alkoxides, using carbonablack as a reducing agent. In Si(OC2H5)4-C2H5 OH-H2 O-NH4OH system, hydrolysis rate increased with increasing reaction temperature and pH. Pure ${alpha}$-Si3N4 was formed at 1350$^{circ}C$ for 5 hrs in N2 atmosphere. In Si(OC2H5)4-Al(OC3H7)3-C6H6-H2 O-NH4OH system, weight loss increased as Si/Al ratio decreased. Single phase ${beta}$-Sialon consisted of Si/Al=2 was formed at 1350$^{circ}C$ in N2 and minor phases of ${alpha}$-Si3N4, AIN, and X-phase were existed besides theSialon phase at other Si/Al ratios. The Si3N4 and Sialon powders synthesized from alkoxides consisted of uniform find particles of 0.05-0.2$mutextrm{m}$ in diameter, respectively.