CN-122010560-A - Method for preparing porous zirconia ceramics by low-temperature sintering

Abstract

The invention discloses a method for preparing porous zirconia ceramics by low-temperature sintering, which comprises the following steps of S1, mixing citric acid, zirconium acetylacetonate and absolute ethyl alcohol according to a certain proportion to obtain a colloid solution A, S2, mixing inorganic yttrium salt, inorganic zirconium salt and water according to a certain proportion to obtain a mixed solution B, S3, slowly adding the colloid solution A into the mixed solution B obtained in the step S2, S4, drying the colloid solution to obtain a dried precursor, S5, calcining the dried precursor at a low temperature to obtain nano yttrium stabilized zirconia powder, S6, ball-milling and spray-granulating the powder to obtain spherical granulating powder with uniform particle size, S7, performing dry-pressing molding and cold isostatic pressing molding to obtain ceramic biscuit to be sintered, and S8, sintering in a muffle furnace to obtain the final porous zirconia ceramics. The powder is subjected to ball milling, granulation, dry pressing and cold isostatic pressing, and the zirconia ceramic with the nanoscale air holes and uniform pore diameter is prepared by low-temperature sintering.

Inventors

• DAI PEIJUN
• WANG JUN

Assignees

• 广漠科技(苏州)有限公司

Dates

Publication Date

20260512

Application Date

20260206

Claims (10)

1. 1. A method for preparing porous zirconia ceramics by low-temperature sintering is characterized by comprising the following steps: s1, mixing citric acid, zirconium acetylacetonate and absolute ethyl alcohol according to a certain proportion to obtain a colloid solution A; s2, mixing inorganic yttrium salt, inorganic zirconium salt and water according to a certain proportion, and heating and dissolving to obtain a mixed solution B; S3, slowly adding the colloid solution A obtained in the step S1 into the mixed solution B obtained in the step S2, and stirring until uniform colloid is formed; s4, drying the colloid liquid obtained in the step S3 to obtain a dried precursor; S5, calcining the dried precursor obtained in the step S4 at a low temperature to obtain nano yttrium-stabilized zirconia powder; s6, ball milling and spray granulating the yttrium stabilized zirconia powder obtained in the step S5 to obtain spherical granulated powder with uniform particle size; S7, carrying out dry press molding and cold isostatic pressing molding on the yttrium stabilized zirconia granulating powder obtained in the step S6 to obtain a ceramic biscuit to be sintered; And S8, placing the ceramic biscuit formed in the step S7 on an alumina firing plate, and sintering in a muffle furnace to obtain the final porous zirconia ceramic.
2. 2. The method for preparing porous zirconia ceramics by low-temperature sintering according to claim 1, wherein in the step S1, the mass ratio of citric acid, zirconium acetylacetonate and absolute ethyl alcohol is 1 (1-40): (1-500); In the step S2, the mass ratio of the inorganic yttrium salt to the inorganic zirconium salt to the water is 1 (1-40): 1-400; The mass ratio of the zirconium acetylacetonate in the colloid solution A to the inorganic zirconium salt in the mixed solution B is 1 (1-40).
3. 3. The method for preparing porous zirconia ceramics by low-temperature sintering according to claim 1, wherein in step S2, the inorganic yttrium salt comprises at least one of yttrium chloride hexahydrate, yttrium nitrate hexahydrate, yttrium acetate tetrahydrate; the inorganic zirconium salt comprises at least one of zirconium chloride, zirconium nitrate pentahydrate and zirconium oxychloride octahydrate.
4. 4. The method for preparing porous zirconia ceramic by low-temperature sintering according to claim 1, wherein the dissolution temperature in the step S2 is 30-100 ℃ and the dissolution time is 1-40 h.
5. 5. The method for preparing porous zirconia ceramics by low-temperature sintering according to claim 1, wherein the stirring time in the step S3 is 1-20 h.
6. 6. The method for preparing porous zirconia ceramics by low-temperature sintering according to claim 1, wherein the drying temperature in the step S4 is 30-100 ℃ and the drying time is 1-40 h.
7. 7. The method for preparing porous zirconia ceramic by low-temperature sintering according to claim 1, wherein the calcination temperature in the step S5 is 400-1200 ℃ and the calcination time is 1-10 h.
8. 8. The method for preparing porous zirconia ceramic by low-temperature sintering according to claim 1, wherein the ball milling mode in the step S6 is planetary ball milling, the ball milling speed is 100-400 rpm, and the ball milling time is 1-40 h.
9. 9. The method for preparing porous zirconia ceramics by low-temperature sintering according to claim 1, wherein the pressure of dry press molding in the step S7 is 1-100 MPa.
10. 10. The method for preparing porous zirconia ceramics by low-temperature sintering according to claim 1, wherein the sintering temperature in the step S8 is 1000-1600 ℃ and the sintering time is 1-600 min.

Description

Method for preparing porous zirconia ceramics by low-temperature sintering Technical Field The invention belongs to the technical field of ceramic preparation, and particularly relates to a method for preparing porous zirconia ceramic by low-temperature sintering. Background Porous zirconia ceramics have wide demands in the fields of high-temperature catalysis, hydrogen energy filtration and the like. However, practical applications of porous zirconia ceramics still face problems such as high-purity raw materials are expensive, sintering temperatures are typically above 1500 ℃, and a certain amount of pore-forming agent is typically required to be added, which results in complex whole process and difficulty in preparing ceramics with uniform pore diameters and nano-scale pores. Therefore, it is highly demanded to prepare zirconia powder with high purity and high sintering activity, so that zirconia ceramics with uniform pore diameter and nano-scale pores can be prepared under the low temperature condition. Disclosure of Invention The invention mainly solves the technical problem of providing a method for preparing porous zirconia ceramics by low-temperature sintering, wherein the zirconia ceramics with uniform pore diameter and nano-scale air holes are prepared by low-temperature sintering after ball milling, granulation, dry pressing and cold isostatic pressing of powder. In order to solve the technical problems, the invention adopts a technical scheme that the method for preparing the porous zirconia ceramics by low-temperature sintering comprises the following steps: s1, mixing citric acid, zirconium acetylacetonate and absolute ethyl alcohol according to a certain proportion to obtain a colloid solution A; s2, mixing inorganic yttrium salt, inorganic zirconium salt and water according to a certain proportion, and heating and dissolving to obtain a mixed solution B; S3, slowly adding the colloid solution A obtained in the step S1 into the mixed solution B obtained in the step S2, and stirring until uniform colloid is formed; s4, drying the colloid liquid obtained in the step S3 to obtain a dried precursor; S5, calcining the dried precursor obtained in the step S4 at a low temperature to obtain nano yttrium-stabilized zirconia powder; s6, ball milling and spray granulating the yttrium stabilized zirconia powder obtained in the step S5 to obtain spherical granulated powder with uniform particle size; S7, carrying out dry press molding and cold isostatic pressing molding on the yttrium stabilized zirconia granulating powder obtained in the step S6 to obtain a ceramic biscuit to be sintered; And S8, placing the ceramic biscuit formed in the step S7 on an alumina firing plate, and sintering in a muffle furnace to obtain the final porous zirconia ceramic. Further, in the step S1, the mass ratio of citric acid, zirconium acetylacetonate and absolute ethyl alcohol is 1 (1-40): 1-500; In the step S2, the mass ratio of the inorganic yttrium salt to the inorganic zirconium salt to the water is 1 (1-40): 1-400; The mass ratio of the zirconium acetylacetonate in the colloid solution A to the inorganic zirconium salt in the mixed solution B is 1 (1-40). Further, in step S2, the inorganic yttrium salt includes at least one of yttrium chloride hexahydrate, yttrium nitrate hexahydrate, yttrium acetate tetrahydrate; the inorganic zirconium salt comprises at least one of zirconium chloride, zirconium nitrate pentahydrate and zirconium oxychloride octahydrate. Further, the dissolution temperature in the step S2 is 30-100 ℃ and the dissolution time is 1-40 h. Further, in the step S3, the stirring time is 1-20 h. Further, the drying temperature in the step S4 is 30-100 ℃ and the drying time is 1-40 h. Further, in the step S5, the calcination temperature is 400-1200 ℃ and the calcination time is 1-10 h. Further, the ball milling mode in the step S6 is planetary ball milling, the ball milling rotating speed is 100-400 rpm, and the ball milling time is 1-40 h. Further, in step S7, the pressure of the dry press molding is 1-100 MPa. Further, in the step S8, the sintering temperature is 1000-1600 ℃ and the sintering time is 1-600 min. The beneficial effects of the invention are at least as follows: The invention prepares high-purity superfine zirconia powder, and the powder is subjected to ball milling, granulation, dry pressing and cold isostatic pressing, and then is sintered at a low temperature in normal pressure and air to prepare zirconia ceramics with uniform pore diameter and nanoscale pores. Drawings FIG. 1 is a cross-sectional SEM image of a sintered ceramic of example 2; FIG. 2 is a cross-sectional SEM image of a sintered ceramic of example 3. Detailed Description The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby mak