Influence of heat treatment in sintering process on characteristics of A[l.sub.2][o.sub.3]-Zr[o.sub.2] ceramics systems

A[l.sub.2][O.sub.3]-Zr[O.sub.2] ceramics containing 5-50 mol% Zr[O.sub.2] were prepared by solid state reaction method. The bulk density, average grain size and microhardness of A[l.sub.2][O.sub.3]-Zr[O.sub.2] ceramics system as function of Zr[O.sub.2] content were investigated. The dense A[l.sub.2][O.sub.3] ceramics were successfully by means of carefully control processing parameters that include sintering temperature and heating/cooling rates. These ceramics with higher Zr[O.sub.2] content was obtained high bulk densities and small grain sizes. However, the high hardness values were exhibited from A[l.sub.2][O.sub.3] ceramics with dopants Zr[O.sub.2] between 1-10mol% and its tend to decrease with concentration of Zr[O.sub.2]. It can be found that the fast heating/cooling rates are controlled grain growth and obtained high hardness in materials. The results gave good correlation between stoichiometry characteristics, heating/cooling rates in sintering and microstructure of fabricated dense and mechanical properties. Key words: A[l.sub.2][O.sub.3]-Zr[O.sub.2] ceramics, microhardness, heating/cooling rates, sintering
INTRODUCTION The most widely used ceramic materials are alumina, A[l.sub.2][O.sub.3] and zirconia, Zr[O.sub.2], because of their excellent bio-compatibility. The main advantage of A[l.sub.2][O.sub.3] is its high hardness and wear resistance, [...]