ZrO2입자의 분산방법에 따른 Al2O3/ZrO2요업체의 특성

Abstract

For the homogeneous dispersion of particles in ceramics, Zr-precusors were mixed with oxide powders by chemical routes such as partial precipitation or partial polymerization of Zr-nitrate solutions. In case of the mechanical mixing of ultrafine and oxide powders, relatively homogeneous dispersion was difficult to achieve so that the particle size and distributions of were relatively inhomogeneous after sintering at high temperature. But when the Zr-Y-hydroxide were co-precipitated to ultrafine oxide powders followed by calcinations, homogeneous dispersion of nano-sized particles in composite ceramics were obtained. But because of the coalescence of dispersed particles, dispersed was grown up to more than 0.2 (200 nm) when sintered at the temperature of higher than But when the sintering temperature was kept to lower than by using nano-sized , the particle size of dispersed could be sustained below 0.1 . But the coalescence of dispersed between particles could not be avoided so that the mechanical properties were not enhanced contrary to the expectations. So Zr-polyester precursors were precipitated and coated to the surface of ultrafine powders by the polymerization of Ethylene Glycol with Citric Acid and Zirconium Nitrate. By this dispersion much more uniform dispersion of was achieved at of sintering temperature ranges. And due to especially discrete dispersion of between particles, their mechanical strength was more enhanced than mechanical mixing or hydroxide precipitation methods.