Sinterability of Yttria-Stabilized Zirconia Powder Prepared by Ultrasonic Spray Freeze-Drying Technique

Tetragonal zirconia poly crystals (Y-TZP)containing 3·0 mole% yttria were prepared by (i) the ultrasonic spraying of solutions containing desired amounts of components into a chamber chilled by liquid nitrogen, (ii)the subliming of the ice from the frozen materials and (iii) the calcining of the remaining materials. The resulting Y-TZP powder was composed of ultrafine primary particles with sizes below 0.05 um. The relative density of Y-TZP compacts fired at 1300°C for 5 hrs attained a maximum of 97·3%%