Preparation of $Al_2O_3$-$ZrO_2$ Composite Powders by the Use of Emulsions : III. Emulsion-Coprecipitation Method

에멀젼을 이용한 $Al_2O_3$-$ZrO_2$복합분체의 제조 : III. 에멀젼-공침법

  • 현상훈 (연세대학교 요업공학과) ;
  • 김의수 (연세대학교 요업공학과)
  • Published : 1990.04.01

Abstract

$Al_2O_3$-20w/o $ZrO_2$ composite powders were prepared by the emulsion-coprecipitation method and the effects of preparative conditions on powder characteristics were investigated. In the preparation of $Al_2O_3$-$ZrO_2$ composite powders, toluene was used instead of kerosene as the oil phase in emulsions. After coprecipitation, the emulsion was easily broken into a single liquid phase by adding methanol, and then precipitates could be effectively collected by filteration. The fact that all $ZrO_2$ phases present at room temperature in composite powders calcined at $1100^{\circ}C$ after washed by methanol had a tetragonal structure confirmed that methanol-washing enhanced the dispersibility of fine $ZrO_2$ particles in $Al_2O_3$ matrix. $Al_2O_3$-$ZrO_2$ composite powders were spherical particles of 0.2${\mu}{\textrm}{m}$ diameter. Pellets sintered at $1650^{\circ}C$ for 2hrs showed the relative theoretical density of 97.3% and the fracture toughness of 5.01MN/$m^{3/2}$.

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References

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