Effect of SiC Dispersion of <TEX>$beta$</TEX>-Sialon Prepared from Wando Pyrophylite

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J. Korean Ceram. Soc. > Volume 25(3); 1988 > Article

Journal of the Korean Ceramic Society 1988;25(3): 261.

완도납석으로부터 제조한 $beta$-Sialon에 대한 SiC의 복합화 효과

이홍림, 김신, 이형직¹

연세대학교 요업공학과
¹현대자동차주식회사 연구소

Effect of SiC Dispersion of $beta$-Sialon Prepared from Wando Pyrophylite

ABSTRACT

$beta$-Sialon powder was prepared by the reduction-nitridation reaction from the mixture of Wando Pyrophyllite and carbon black at 135$0^{circ}C$ in $N_2$ atmosphere. $beta$-SiC powder was added to the prepared $beta$-Sialon powder to make $beta$-Sialon-SiC composite. The $beta$-Sialon-SiC composites were sintered pressurelessly at 175$0^{circ}C$ for 2h, using $Y_2O_3$ and $ZrO_2$(monoclinic) as sintering aids. Comparatively higher values of the fracture toughness (3.8 MN/㎥/2), M.O.R. (470 MN/$m^2$) and vickers microhardness (13.7 MN/$m^2$) were obtained when 10 wt% $Y_2O_3$ was added as a sintering aid. The improved fracture toughness and M.O.R. are assumed to be the results of crack deflection and crack branching by the second phase SiC particles.