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ZrO 2 because of its high strength, high wear resistance, high melting point, low thermal conductivity and high corrosion resistance and other excellent performance, making it important technological materials. Zirconia ceramic material due to these unique mechanical and electronic properties make them widely used in structural materials, thermal barrier coatings, oxygen sensors, fuel cells, catalysts and catalytic carrier, complete circuit of a wide range of high thermoplastic insulation materials, metal oxide semiconductor various fields. Narrow particle size distribution superfine powder helps reduce the firing temperature of the ceramic, and to improve the microstructure of the ceramic structure, thereby improving the performance of the ceramic. In this study, zirconium oxychloride and yttrium nitrate as raw material, NH 3 H 2 O as the precipitating agent, the sol - gel method, pressure - hydrothermal method and supercritical fluid drying (SCFD) Preparation of ZrO 2 powder from the dispersion is good to prepare, and prominent anti-aging properties Quartet nano ZrO 2 powders, research the initial zirconium salt solution concentration, precipitation agent aqueous ammonia was added and the addition rate, the PH value of the solution as well as the aging time of ZrO 2 powder agglomeration state, phase composition, particle size, and the powder morphology impact; 2 powder phase composition and grain size of the nano-ZrO quantitative analysis. Test methods and use of DTA, XRD, and TEM characterization of powders after heat treatment performance. The results show that the sol - gel method and pressure - hydrothermal prepared zirconia powder is substantially amorphous state, the crystallization temperature of 500 ℃; With the increase of pressure, the degree of the powder crystallization gradually increased , when the pressure value reaches the critical pressure, powder basic crystallization; certain amount of the stabilizer Y 2 O 3 incorporation, can make the high temperature stability of the zirconium oxide phase ( t-ZrO 2 ) exists, and With Y 2 O 3 increase in the amount of the content of the tetragonal phase gradually increased, crystalline state at room temperature particle size change when the doping amount at 3.0mol%, average grain size as small as 6nm, the content of tetragonal phase of 80%; as the calcination temperature, and the extension of the time, ZrO 2 Powders average grain size increases, the t-ZrO 2 the gradual to m-ZrO 2 transition, when the temperature reached 950 ° C, the powder substantially free t-ZrO 2 ; With the heat treatment temperature and time. microscopic strain has been reduced, when the temperature reaches 950 ° C, the powder micro-strain of the basic approaches zero; supercritical fluid drying the prepared nano zirconia tetragonal, with an average particle size of less than 10 nm, since the dispersion at 500 ℃ for 6h after the particles grow no more than 5nm, and with the extension of the heat treatment time microscopic strain decreased.
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