Synthesis of <TEX>$beta$</TEX>다-Sialon with Various Compositions from Kaolin

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J. Korean Ceram. Soc. > Volume 23(5); 1986 > Article

Journal of the Korean Ceramic Society 1986;23(5): 17.

카올린으로부터 조성이 다른$beta$다-Sialon의 합성

최상욱, 서규식, 이종진

인하대학교 공과대학 무기재료공학과

Synthesis of $beta$다-Sialon with Various Compositions from Kaolin

ABSTRACT

β'-Sialon with different compositions was synthesized by the carbothermal reduction-nitridation of compacts containing kaolin graphite and silicon or aluminum at temperature of 1300-1450℃ under flowing gas of 90% N2-10% H2 or 20hrs. Quantitative analysis of minerals which were formed in the specimens was carried out by using the calibration curve which has been prepared from X-ray diffraction patterns. The obtained results were as follows : 1. In the formation of β'-Sialon by carbothermal reduction-nutridation of Si-Al-O-C system mixtures at 1400℃ for 20hrs. (2) β'-Sialon as a major mineral and α-Al2O3 as a minor mineral were identified in the specimen which was prepared of kaolin and graphite. (3)α-Al2O3 and 15R as a minor minerals were measured in the specimen which was prepared of kaolin aluminum and graphite. (4) AlN instead of α-Al2O3 and 15R was formed in the compacts that excess graphite(=35 wt%) was added to the mixture of kaolin and aluminium. 2. As the reaction time and temperature were increased the formation of β'-Sialon was increased whereas the phases of mllite SiC and Si2ON2 were decreased gradually.