Preparation of <TEX>$ZrO_2/Al_2O_3-Mullite$</TEX> Composites Using the Silica Sol Infiltration Method

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J. Korean Ceram. Soc. > Volume 29(9); 1992 > Article

Journal of the Korean Ceramic Society 1992;29(9): 719.

실리카 졸 침투법을 이용한 $ZrO_2/Al_2O_3-Mullite$ 복합체의 제조

현상훈, 최지영

연세대학교 세라믹공학과

Preparation of $ZrO_2/Al_2O_3-Mullite$ Composites Using the Silica Sol Infiltration Method

ABSTRACT

ZrO2/Al2O3-Mullite composites were prepared by infiltration of the silica sol to the porous ZrO2/Al2O3 bodies. The porous ZrO2/Al2O3 bodies for infiltration were fabricated using ZrO2 (20wt%)/Al2O3 composite powders synthesized by the emulsion-hot kerosene drying method. The preparation of silica sols was conducted by the hydrolysis-peptization of an alcoholic TEOS solution. When ZrO2/Al2O3-Mullite and ZrO2/Al2O3 composites were sintered at 1$650^{circ}C$ for 4 hrs, both of them showed an excellent sinterability. As the amount of mullite added in the composites increased, the ratio of the tetragonal phase of zirconia to the monoclinic phase at the room temperature became higher. It was known that values of the fracture toughness of the ZrO2/Al2O3-Mullite composites were about 5.48 MPa.m1/2 much larger than that of the ZrO2/Al2O3 system.