SINTERING AND CHARACTERIZATION OF YTTRIA-STABILIZED CUBIC ZIRCONIA WITH ALUMINA DERIVED FROM SOLID-SOLUTION

In the composition of ZrO2(8 mol% Y2O3)/Al2O3=(100-85)/(0-15) mol%, metastable c-ZrO2 solid solutions crystallize at low temperatures from amorphous materials prepared by the hydrazine method. Powders have been characterized. Crystallite size and specific surface area are strongly dependent on heating temperature. Hot isostatic pressing has been performed for 1 h at 1600-degrees-C under 196 MPa. Yttria-stabilized c-ZrO2 materials with homogeneous-dispersed Al2O3 derived from the decomposition of solid solutions give >99% of theoretical densities. Materials with small amounts of Al2O3 show good strength and excellent high ionic conductivity at high temperatures.