The Isothermal Phase Transformation by Low Temperature Aging in Y-TZP Powders

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J. Korean Ceram. Soc. > Volume 27(8); 1990 > Article

Journal of the Korean Ceramic Society 1990;27(8): 971.

저온 열처리에 의한 Y-TZP 분말의 등온 상전이

이종국, 김환

서울대학교 무기재료공학과

The Isothermal Phase Transformation by Low Temperature Aging in Y-TZP Powders

ABSTRACT

The ifluence of transformability and stabilized effects in tetragonal phase on the isothermal phase transformation of Y-TZP at low temperature were investigated. The transformability of Y-TZP powders were gradually increased with calcination temeprature and reached maximum at critical temperature, but when the Y-TZP powders were calcined above critical temperature, transformability of Y-TZP were gradually decreased with increasing calcination temperature. It was concluded that maximum transformability was appeared because particle size effects decreased and constrain effects increased with calcined temperature. The isothermal phase transformation during aging at 25$0^{circ}C$ only observed in Y-TZP stabilized by constrain effects and the amounts of transformation during aging at 25$0^{circ}C$ only observed in Y-TZP stabilized by constrain effects and the amount of transformed monoclinic phase during aging decreased with increasing constrain effects. From these results, the mechanism of isothermal phase transformation and degradation behaviors at low temperature in Y-TZP was concluded that occurred by decreasing of constrain effects due to stress relaxation at grian boundary.