COMPARATIVE ANALYSIS OF POWDER SYNTHESIS ROUTES FOR THE ZrO2(Y2O3)– Al2O3 SYSTEM USING MECHANICAL MIXING, COPRECIPITATION, AND SEPARATE PRECIPITATION

This study examines how different powder synthesis routes influence the structural evolution and functional properties of ZrO2(Y2O3)–Al2O3 composite ceramics. Three preparation methods were compared: mechanical mixing of commercial oxides, co-precipitation from mixed salt solutions, and stepwise chemical precipitation of individual components. The resulting powders were analyzed in terms of morphology, phase composition, and particle-size distribution, and their behavior during sintering was evaluated by X-ray diffraction, scanning electron microscopy, and laser granulometry. Mechanical mixing led to heterogeneous phase distribution and residual porosity in the sintered ceramics, indicating insufficient stabilization and limited reactivity of the starting powders. Co-precipitated compositions exhibited a finer structure, though deviations from the intended stoichiometry occurred due to unequal hydrolysis rates of zirconium and aluminum ions. The most consistent results were obtained for powders produced by stepwise precipitation, which ensured uniform yttria distribution, high chemical homogeneity, and en-hanced sintering activity. Ceramics derived from these powders demonstrated the highest density, minimal open porosity, and improved hardness and fracture toughness. Overall, the findings show that stepwise precipitation is the most effective route for producing chemically homogeneous ZrO2(Y2O3)–Al2O3 powders suitable for high-performance structural ceramics.