Crystallization in seeded zirconia precipitates

Abstract

Co-precipitation of mixed zirconium oxynitrate and yttrium nitrate in a diluted ammonia solution (pH 10-10.5) has been used to prepare 3 mol% Y2O3 stabilized zirconia powders. The addition of ultra-fine zirconia particles (crystalline size < 10 nm) in the co-precipitated amorphous zirconium hydroxides results in a decrease in the crystallization temperature of zirconia, from 458°C for the unseeded composition to 434°C for the composition containing 30 wt% ultra-fine zirconia particles. In contrast, the addition of zirconia particles of 60 to 70 nm in crystalline sizes in the co-precipitated zirconium hydroxides has no effect on the crystallization temperature.