Microstructures and Densification Behaviors of <TEX>$Al_2O_3-ZrO_2(ZTA)$</TEX> Composites Fabricated by a Surface-induced Coating

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J. Korean Ceram. Soc. > Volume 31(1); 1994 > Article

Journal of the Korean Ceramic Society 1994;31(1): 17.

표면-유기 코팅에 의해 합성한 $Al_2O_3-ZrO_2(ZTA)$ 복합체의 미세구조와 소결거동

장현명, 문종하, 김광수

포항공과대학교 재료공학과 정밀세라믹스 공정과학연구실

Microstructures and Densification Behaviors of $Al_2O_3-ZrO_2(ZTA)$ Composites Fabricated by a Surface-induced Coating

ABSTRACT

Al2O3-ZrO2(ZTA) composites were fabricated by a surface-induced coating of the precursor for the ZrO2 phase on the kinetically stable colloid particles of Al2O3. The fabricated composites were characterized by a uniform spatial distribution of the dispersed ZrO2 phase and by the absence of large ZrO2 grains throughout the Al2O3 matrix. The fracture toughness (KIC) and the bending strength of ZTA composites sintered at 1$600^{circ}C$, respectively, were 5.6 MPa.m1/2 (for 20 wt% ZrO2) and 600 MPa (for 15wt% ZrO2). The fraction of tetragonal ZrO2 phase decreases as the total content of ZrO2, suggesting that both the stress-induced tlongrightarrowm transformation and the microcrack nucleation contribute to the toughening of the ZTA composites fabricated by the surface-induced coating.