Effects of Na2O Content on Characteristics of <TEX>$beta$</TEX>-Al2O3

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

Journal of the Korean Ceramic Society 1987;24(1): 9.

$beta$-Al2O3의 특성에 미치는 Na2O의 영향

윤기현, 김응수, 송효일¹

연세대학교 요업공학과
¹삼성전자 중앙연구소

Effects of Na2O Content on Characteristics of $beta$-Al2O3

ABSTRACT

Physical and electrical properties of ${beta}$-Al2O3 were investigated as function of Na2O content from 6.67 wt.% to 13.19 wt.%. The majority phase is ${beta}$-Al2O3 and the small amount of ${beta}$"-Al2O3 exists in the specimens sintered at 1600$^{circ}$for 30 mins. In the case of specimens with 8.54 wt.% Na2O sintered at 1600$^{circ}C$, the relative amount of ${beta}$-Al2O3 phase increases and that of ${beta}$"-Al2O3 phase decreases with increasing sintering time, and then ${beta}$"-Al2O3 phase does not exist if sintering time is over 8 hrs. As the Na2O content is increased, the 3-Point MOR and the resistivity are decreased. However, density and 3-Point MOR with increasing sintering time are decreased due to increasing the enclosed pore trapped inside of the exaggerated grains. As the sintering time is increased, the average grain size and the duplexity of microstructure are increased, and the resistivity is slightly decreased.