UNIFORM-COMPOSITION ZIRCONIA SOLID SOLUTION MONODISPERSE FINE GLOBULAR POWDER AND ITS PRODUCTION

摘要

PURPOSE: To obtain the powder excellent in dispersibility by hydrothermally treating an aq. soln. contg. specified amts. of Zr compd. and hydrochloric acid at ≥100°C, immobilizing the compd. into a monoclinic globular zirconia superfine particle and coating the surface with a hydroxide, etc. ;CONSTITUTION: A soln. consisting of one mol of Zr compd. (as ZrO₂), 0.8-2mols of HCI and 6-10mols of H₂O is hydrothermally treated at 100-220°C in a closed vessel to obtain monodisperse monoclinic globular zirconia fine particles having 0.2-0.8μm diameter. The particle is vacuum-dried, then heat-treated at ≥100°C and immobilized into the globular fine particle stable to water. The fine particle is dispersed in the soln. of the soluble salts of rare-earth elements (Se, Y, Yb) and urea to obtain a uniform mixed suspension. A hydroxide, etc., are then deposited on the fine particle surface by the homogeneous precipitation due to the theraml decomposition of the urea in the soln. The coated particle is calcined at ≥700°C to cause it to enter into solid soln.;COPYRIGHT: (C)1995,JPO