PREPARATION OF NANOMETER ZrO_2-8% Y_2O_3 POWDERS BY AZEOTROPIC DISTILLATION PROCESSING

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Gels of Zr(OH) 4 and Y(OH) 3, prepared by the chemical coprecipitation method, were effectively dehydrated by the azeotropic distillation processing. Because of the removal of interparticle free water, replacement of surface hydroxyl groups with butoxy groups and steric effects of n butanol, colse approach of gel particles and Zr O Zr chemical bond formation between them were prevented. Nanometer ZrO 2 8%(mole fraction, %)Y 2O 3 powders prepared by this processing, with the average particle size of 16 nm, can be sintered to 98.5% TD at 1 450 ℃ for 2 h with an average grain size of ceramic of 0.3 μm.