Preparation method of high-dispersion nano-zirconia powder

Abstract

The invention belongs to the technical field of ceramic powder preparation, and particularly relates to a preparation method of high-dispersion nano-zirconia powder. According to the method, doped yttrium metal modification, preparation of a precursor by a co-precipitation method and hydrothermal crystallization are combined to obtain the high-purity and high-dispersion nano-zirconia powder, impurity ions in the precursor are removed by an ultra-filtration composite membrane technique, crystal form control and particle dispersion functions of a mineralizer are more effectively achieved in hydrothermal reaction, the concentration of the nano-zirconia powder in the precursor is improved, and high-purity and high-yield nano-powder is prepared. The nano-zirconia powder with stable yttrium prepared by the method has a spherical particle shape, is narrow in particle size distribution, good in dispersibility, high in purity, free from aggregation and the like and can be widely applied to high-end biological ceramic materials, and the method solves the problem of brittleness of a current zirconia material in the transition process of crystal forms, so that zirconia ceramics are flexibly and widely applied.

Description

technical field [0001] The invention belongs to the technical field of ceramic powder preparation, and in particular relates to a preparation method of high-purity and high-dispersion nano-zirconia. Background technique [0002] Zirconia ceramics have excellent physical and chemical properties, such as anti-corrosion, anti-wear, impact resistance, heat insulation, ceramic insulation, high temperature resistance and electricity insulation, and are widely used in catalysis, oxygen sensitive sensors, and high-temperature solid-state fuel cells. , Refractory materials, chemically inert surface materials, appearance decoration materials and biological materials, etc., have become one of the hot spots of research and development today. [0003] Zirconium dioxide (ZrO2) has a special property - martensitic phase transformation. With the change of temperature, the structure of ZrO2 can change. The low temperature is monoclinic ZrO2 (m-ZrO2), and the high temperature is 1170 ° C. It ...

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Problems solved by technology

[0003] Zirconium dioxide (ZrO2) has a special property - martensitic phase transformation. As the temperature changes, the structure of ZrO2 can change. The low temperature is monoclinic ZrO2 (m-ZrO2), and the high temperature reaches 1170 ° C. It is all transformed into tetragonal ZrO2 (t-ZrO2), and then heated to 2370 ° C to transform into cubic ZrO2 (c- ZrO2), and this is a reversible phase transition process, and the transition process is accompanied by shear strain and volume change, so that the zirconia material The thermal shock resistance of the material is greatly reduced and the material cracks, which seriously limits the application of zirconia ceramics.

At present, the methods for preparing zirconia powder include hydrolysis method, precipitation method, microemulsion method, hydrothermal method, high-temperature spray pyrolysis method, spray inductively coupled plasma method and freeze-drying method, among which the coprecipitation method has simple and easy process requirements. Add other oxides as stabilizers, but this method is easy to introduce other impurity elements to cause a decrease in purity, the formed colloidal precipitate is difficult to wash, the filtration speed is slow, and high temperature calcination is required, and block agglomeration is prone to occur during the drying process; and The hydrothermal method can directly obtain crystalline oxides from the solution, avoiding the traditional calcination process of converting hydroxides into oxides, and its particle size and shape can be controlled, reducing the introduction of external impurities and the generation of hard polymers. Possible, but overall process costs are higher and yields are lower

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