Mechanical Properties of Partially Stabilized <TEX>$alpha$</TEX>-Sialon Synthesized from Kimcheon Quartzite

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J. Korean Ceram. Soc. > Volume 25(2); 1988 > Article

Journal of the Korean Ceramic Society 1988;25(2): 143.

김천규석으로부터 제조한 부분안정화 $alpha$-Sialon의 기계적 물성

서원선, 조덕호¹, 이홍림

연세대학교 요업공학과
¹국립공업시험원

Mechanical Properties of Partially Stabilized $alpha$-Sialon Synthesized from Kimcheon Quartzite

ABSTRACT

In order to synthesize the partially stabilized $alpha$-Sialon, A1N and Y2O3 were added to synthesized $alpha$-Si3N4. The phase composition, mechanical properties, micro structure, etc, of the synthesized $alpha$-Sialon were investigated. Partially stabilized $alpha$-Sialon ceramics could be synthesized from the composition which was a little deviated from x=0.4, x=0.6 composition along the Si3N4.0.1Y2O3:0.9AlN tie line at 1750-180$0^{circ}C$ for 2 hrs in N2 atmosphere. It is assumed that A1N is more closely related than Y2O3 to the formation of $alpha$-Sialon, and that A1N is more easily dissolved into $alpha$-structure than into $beta$-structure. In Ya2O3-rich phase mechanical properties were observed to be poor because of formation of mellilite, grain growth, and thermal decomposition of $alpha$-Sialon. The maximum values of M.O.R, KIC and hardness are 723 MPa, 4.5MN/㎥/2 and 19.3 GPa, respectively, and they were observed for the $alpha$-Sialon ceramics sintered at 178$0^{circ}C$.