Preparation of Y-doped zirconia by emulsion technique
Spherical Y-doped zirconia powders have been prepared from water in oil-emulsions of acid stabilized aqueous sols. The precipitation of hydroxides inside the droplets was achieved by an ion exchange process between the aqueous phase and an anion exchange resin, using a phase transfer catalyst as a carrier for the anions through the organic solvent. Azeotropic distillation of the water caused a densification to spherical amorphous particles. Filtration, drying and calcination led to the formation of a tetragonal zirconia powder. Isostatically pressed powder compacts sintered at 1650 degree C to theoretical density.