Microstructure and Mechanical Properties of <TEX>$Al_2O_3$</TEX>-<TEX>$ZrO_2$</TEX>-Nb Composites Prepared by Reaction Sintering

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J. Korean Ceram. Soc. > Volume 28(5); 1991 > Article

Journal of the Korean Ceramic Society 1991;28(5): 422.

반응소결로 얻어진 $Al_2O_3$-$ZrO_2$-Nb 복합체의 미세구조와 기계적 성질

이수민, 신유선¹, 강석중¹, R.J. Brook²

한국전자통신연구소
¹Max-Plank 금속연구소
²Oxford University

Microstructure and Mechanical Properties of $Al_2O_3$-$ZrO_2$-Nb Composites Prepared by Reaction Sintering

ABSTRACT

The reaction sintering of Al2O3-ZrO2-Nb composite has been investigated using Al2O3, and ZrAl2 powders. Two kinds of specimens, 78.3Al2O3-14.0Nb2O5-7.7ZrAl2 in wt.% (AZN-5) and 72.3Al2O3-13.8Nb2O5-7.5ZrAl2-6.4ZrO2(AZN-10), were prepared. Powder compacts were sintered at various temperatures between 1$600^{circ}C$ and 1$700^{circ}C$ for 30 min in Ar. DTA and X-ray analysis have showen that a reaction between Nb2O5 and ZrAl2 started at 149$0^{circ}C$ to form Al2O3, ZrO2, and Nb. The sintered density increased with the sintering temperature. AZN-10 specimen showed higher density than AZN-5 specimen for almost all the experimental conditions. Al2O3-ZrO2-Nb composite hot pressed after reaction sintering showed higher toughness and lower hardness than hot pressed Al2O3-ZrO2. The crack propagated through many metallic Nb particles which showed plastic deformation, and this is the cause of the increase in toughness of Al2O3-ZrO2-Nb composite over Al2O3-ZrO2.