Correlations among sintering temperature, shrinkage, and open porosity of 3.5 YSZ/Al2O3 composites

Slip-cast ceramic samples of the system (100−x) (ZrO2-3.5 mol% Y2O3)-xAl2O3 (abridged as (100−x) 3.5 YSZ/xAl2O3 composite, where x is expressed in wt%) were examined using dilatometry, isothermal sintering and electron microscopy methods. The shrinkage in the range 1100-1300 °C was found to be higher for the (100−x) 3.5 YSZ/xAl2O3 samples with prevailing fraction of PSZ than for the composites with a corundum matrix. When the weight fraction of corundum was increased, the relative shrinkage of the (100−x) 3.5 YSZ/xAl2O3 samples decreased and the open porosity of the ceramic materials grew. The effect of -Al2O3 impurity on the sintering process and linear dimensions of ceramics is shown. Heat treatment of (50-40) 3.5 YSZ/(50-60) Al2O3 composites at 1300 °C are proposed as the optimum conditions for porous diaphragm formation.