Effects of Aging on Properties of MgO-Partially Stabilized Zirconia

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J. Korean Ceram. Soc. > Volume 24(3); 1987 > Article

Journal of the Korean Ceramic Society 1987;24(3): 243.

마그네시아 부분안정화 지르코니아 소결체의 특성에 미치는 열처리 효과

정형진, 오영제, 이홍림¹

한국과학기술원 무기재료연구실
¹연세대학교 요업공학과

Effects of Aging on Properties of MgO-Partially Stabilized Zirconia

ABSTRACT

The effects aging on some properties and thermal-shock behavior of zirconia partially stabilized with 9 mol% MgO (9MZ) were studied. 9MZ specimens were aged over $1200^{circ}$-$1400^{circ}C$ for 12hours subsequently, after sintering at $1650^{circ}C$ for 4 hours. Fracture strength(both before and after thermal-shock test), linear thermal expansion, monoclinic fraction and phase transition by XRD, density, galvanic potential and microstructure were measured. Quantitative chemical analysis around the grain-boundary of the specimen aged at $1350^{circ}C$ was also conducted by EDX. The aging of 9MZ specimen causes a thermal decomposition of cubic-$ZrO^{2}$ into the formation metastable tetragonal-$ZrO^{2}$ and MgO. The former increases the residual strength after thermal-shock test and the latter improves the thermal-shock resistance due to thermal conduction through the continuous magnesia phase and the formation of monoclinic phase content in matrix were increased with decreasing the aging temperature from $1400^{circ}C$ to $1200^{circ}C$. Galvanic potential of the aged specimen exhibited a proper emf characteristic.