Preparation method and application of high-toughness anti-aging zirconia ceramic

Abstract

The invention discloses a preparation method and application of high-toughness anti-aging zirconia ceramic, and relates to the technical field of ceramic materials.The preparation method comprises the following steps that nano monoclinic zirconia with the D50 being 20-50 nm and the mass fraction being 99.7-99.8 wt%, aluminum oxide with the D50 being 200-400 nm and the mass fraction being 0.2-0.3 wt% and a dispersing agent are taken, and the dispersing agent accounts for 1-1.5 wt% of the total mass of powder; the preparation method comprises the following steps: by taking a high-purity aluminum oxide grinding ball as a grinding medium, stirring and grinding for 2-4 hours at the rotating speed of 700-1000r / min, and then grinding for 1-2 hours at the sanding rotating speed of 1500-2000r / min to obtain mixed slurry; nano monoclinic zirconia is adopted as a raw material, aluminum oxide and a dispersing agent are added for co-grinding, Y2O3 is deposited on the surface of ATZ composite powder in a magnetron sputtering mode, and a Y2O3 deposition layer can inhibit conversion from t-zirconia to m-zirconia, so that the anti-aging performance of the zirconia ceramic is improved, and the service life of the zirconia ceramic is prolonged. And the nano monoclinic zirconium oxide is directly mixed and ground with the aluminum oxide, so that the zirconium oxide raw material is more easily subjected to stress-induced phase change, and the toughness performance of the zirconium oxide ceramic is improved.

Description

Technical Field

[0001] This invention relates to the field of ceramic materials technology, specifically to a method for preparing and applying high-toughness, aging-resistant zirconia ceramics. Background Technology

[0002] Zirconia ceramics possess excellent strength and toughness, making them widely used in medical, aerospace, chemical, and electronic fields. Zirconia is typically composed of yttrium-stabilized tetragonal zirconia, and depending on the yttrium content, it can be categorized into partially stabilized, fully stabilized, and polycrystalline stabilized zirconia ceramics. Fully stabilized and partially stabilized zirconia ceramics have poorer mechanical properties and are generally not used as structural ceramics.

[0003] Polycrystalline stabilized zirconia possesses excellent mechanical properties and is commonly used in structural ceramics. However, it suffers from low-temperature aging, stress-induced aging, and environment-induced aging. This is because stable tetragonal zirconia gradually transforms into monoclinic zirconia under these conditions, resulting in volume expansion and inducing microcracks. When these cracks propagate to a certain extent, the material fails. Furthermore, the toughness of existing polycrystalline stabilized zirconia is typically around 8 MPa·m. 1 / 2 However, due to their limited toughness, they are not suitable for environments requiring high toughness and aging resistance. Therefore, a method for preparing and applying high-toughness, aging-resistant zirconia ceramics is needed to address these issues. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing and applying high-toughness, aging-resistant zirconia ceramics, in order to solve the problems existing in the prior art as mentioned in the background section.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A method for preparing high-toughness, aging-resistant zirconia ceramics includes the following steps: S1: Take nano-monoclinic zirconium oxide with a D50 of 20-50 nm, with a mass fraction of 99.7-99.8 wt%; alumina with a D50 of 200-400 nm, with a mass fraction of 0.2-0.3 wt%; and a dispersant, the dispersant being 1-1.5 wt% of the total powder mass. S2: Using high-purity alumina grinding balls as the grinding medium, the mixture is stirred and ground for 2-4 hours at a speed of 700-1000 r / min, and then ground for 1-2 hours at a speed of 1500-2000 r / min to obtain a mixed slurry. S3: Spray granulation of the mixed slurry to obtain uniform ATZ composite powder; S4: Y2O3 is deposited on the surface of ATZ composite powder by magnetron sputtering to a thickness of 0.01-0.03 μm to obtain uniform composite powder; S5: The composite powder obtained in S4 is dry-pressed into a green body; S6: High-toughness and aging-resistant zirconia ceramics are obtained by sintering the green blanks.

[0006] Preferably, the diameter of the high-purity alumina grinding ball in S2 is 0.2-0.4 mm.

[0007] Preferably, in S3, the spray speed is set to 15000-20000 r / min, the inlet temperature is set to 220±5℃, and the outlet temperature is set to 110℃±10℃.

[0008] Preferably, in step S5, the pressure for dry pressing is set to 200 MPa.

[0009] Preferably, in step S6, the sintering heating rate of the green embryo is set to 0.5℃ / min, sintering is carried out under a protective argon atmosphere, the temperature is set to 1500℃, and the holding time is 4h.

[0010] The present invention also provides an application of zirconia ceramics, which are used in the manufacture of components for medical, aerospace, chemical and electronic devices.

[0011] Compared with the prior art, the beneficial effects of the present invention are: This invention uses nano-monoclinic zirconia as raw material, adds alumina and dispersant for co-milling, and then deposits Y2O3 on the surface of ATZ composite powder by magnetron sputtering. The Y2O3 deposit layer can inhibit the transformation of t-zirconia to m-zirconia, thereby improving the anti-aging performance of zirconia ceramics. Furthermore, the direct mixing and grinding of nano-monoclinic zirconia with alumina makes the zirconia raw material more susceptible to stress-induced phase transformation, thereby improving the toughness of zirconia ceramics. Detailed Implementation

[0012] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0013] This invention provides the following technical solutions: Example 1 S1: Take 99.7 wt% monoclinic zirconium oxide with a D50 of 30 nm, 0.3 wt% alumina with a D50 of 200 nm, and a dispersant, the dispersant being 1 wt% of the total powder mass; S2: Using high-purity alumina grinding balls with a diameter of 0.3 mm as the grinding medium, the mixture was stirred and ground at 700 r / min for 2 hours, and then ground at 1500 r / min for 2 hours to obtain a mixed slurry. S3: Spray granulation is performed on the mixed slurry. The spray speed is set to 15000 r / min, the inlet temperature is set to 220℃, and the outlet temperature is set to 110℃ to obtain uniform ATZ composite powder. S4: Y2O3 was deposited on the surface of ATZ composite powder by magnetron sputtering to a thickness of 0.01 μm, resulting in a uniform composite powder. S5: The composite powder obtained in S4 is dry-pressed at 200 MPa to obtain a green body; S6: Sintering was carried out at a heating rate of 0.5℃ / min under a protective argon atmosphere at a temperature of 1500℃ for 4 hours to obtain high-toughness and aging-resistant zirconia ceramics.

[0014] The zirconia ceramic prepared in Example 1 was subjected to performance tests, and its strength reached 1400 MPa, its density reached 99%, and its fracture toughness reached 20 MPa·m. 1 / 2 After 48 hours of hydrothermal aging, the monoclinic zirconium oxide volume fraction on the surface was 19.2%.

[0015] Example 2 S1: Take 99.7 wt% monoclinic zirconium oxide with a D50 of 50 nm, 0.3 wt% alumina with a D50 of 200 nm, and a dispersant, the dispersant being 1 wt% of the total powder mass; S2: Using high-purity alumina grinding balls with a diameter of 0.3 mm as the grinding medium, the mixture was stirred and ground at 700 r / min for 2 hours, and then ground at 1500 r / min for 2 hours to obtain a mixed slurry. S3: Spray granulation is performed on the mixed slurry. The spray speed is set to 15000 r / min, the inlet temperature is set to 220℃, and the outlet temperature is set to 110℃ to obtain uniform ATZ composite powder. S4: Y2O3 was deposited on the surface of ATZ composite powder by magnetron sputtering to a thickness of 0.01 μm, resulting in a uniform composite powder. S5: The composite powder obtained in S4 is dry-pressed at 200 MPa to obtain a green body; S6: Sintering was carried out at a heating rate of 0.5℃ / min under a protective argon atmosphere at a temperature of 1500℃ for 4 hours to obtain high-toughness and aging-resistant zirconia ceramics.

[0016] The difference between Example 2 and Example 1 is that the particle size of the nano-monoclinic zirconia was changed from 30 nm to 50 nm. Performance tests were conducted on the zirconia ceramic prepared in Example 2, and its strength reached 1390 MPa, density reached 99%, and fracture toughness reached 20.2 MPa·m. 1 / 2 After 48 hours of hydrothermal aging, the monoclinic zirconium oxide volume percentage on the surface was 19%.

[0017] Example 3 S1: Take 99.7 wt% monoclinic zirconium oxide with a D50 of 30 nm, 0.3 wt% alumina with a D50 of 200 nm, and a dispersant, the dispersant being 1 wt% of the total powder mass; S2: Using high-purity alumina grinding balls with a diameter of 0.3 mm as the grinding medium, the mixture was stirred and ground at 700 r / min for 2 hours, and then ground at 1500 r / min for 2 hours to obtain a mixed slurry. S3: Spray granulation is performed on the mixed slurry. The spray speed is set to 15000 r / min, the inlet temperature is set to 220℃, and the outlet temperature is set to 110℃ to obtain uniform ATZ composite powder. S4: Y2O3 was deposited on the surface of ATZ composite powder by magnetron sputtering to a thickness of 0.02 μm, resulting in a uniform composite powder. S5: The composite powder obtained in S4 is dry-pressed at 200 MPa to obtain a green body; S6: Sintering was carried out at a heating rate of 0.5℃ / min under a protective argon atmosphere at a temperature of 1500℃ for 4 hours to obtain high-toughness and aging-resistant zirconia ceramics.

[0018] The difference between Example 3 and Example 1 is that the Y₂O₃ deposition thickness is 0.02 μm. Performance tests on the zirconia ceramic prepared in Example 3 showed a strength of 1380 MPa, a density of 99%, and a fracture toughness of 20.5 MPa·m. 1 / 2 After 48 hours of hydrothermal aging, the monoclinic zirconium oxide volume percentage on the surface was 20.4%.

[0019] Example 4 S1: Take 99.7 wt% monoclinic zirconium oxide with a D50 of 30 nm, 0.3 wt% alumina with a D50 of 200 nm, and a dispersant, the dispersant being 1 wt% of the total powder mass; S2: Using high-purity alumina grinding balls with a diameter of 0.3 mm as the grinding medium, the mixture was stirred and ground at 700 r / min for 2 hours, and then ground at 1500 r / min for 2 hours to obtain a mixed slurry. S3: Spray granulation is performed on the mixed slurry. The spray speed is set to 15000 r / min, the inlet temperature is set to 220℃, and the outlet temperature is set to 110℃ to obtain uniform ATZ composite powder. S4: Y2O3 was deposited on the surface of ATZ composite powder by magnetron sputtering to a thickness of 0.03 μm, resulting in a uniform composite powder. S5: The composite powder obtained in S4 is dry-pressed at 200 MPa to obtain a green body; S6: Sintering was carried out at a heating rate of 0.5℃ / min under a protective argon atmosphere at a temperature of 1500℃ for 4 hours to obtain high-toughness and aging-resistant zirconia ceramics.

[0020] The difference between Example 4 and Example 1 is that the Y₂O₃ deposition thickness is 0.03 μm. Performance tests on the zirconia ceramic prepared in Example 4 showed a strength of 1350 MPa, a density of 99%, and a fracture toughness of 21 MPa·m. 1 / 2 After 48 hours of hydrothermal aging, the monoclinic zirconium oxide volume percentage on the surface was 22%.

[0021] Comparative Example 1 Zirconia powder with a D50 of 30 nm was dry-pressed at 200 MPa to obtain a green body. The green body was then sintered at 1500 °C for 4 h under a protective argon atmosphere at a heating rate of 0.5 °C / min. The zirconia ceramic obtained in Comparative Example 1 was tested and found to have a strength of 1200 MPa, a density of 99%, and a fracture toughness of 8.5 MPa·m. 1 / 2 After 48 hours of hydrothermal aging, the monoclinic zirconium oxide volume ratio on the surface is 80%.

[0022] Based on the test results of Examples 1-4 and Comparative Example 1, it can be concluded that the zirconia ceramics prepared by the method of the present invention have better properties than those of zirconia ceramics obtained by sintering 3Y zirconia in the traditional way, especially in terms of fracture toughness and anti-aging properties.

[0023] Traditional 3Y zirconia is typically produced by mixing an aqueous solution of zirconium oxychloride with a yttrium chloride stabilizer, adding an alkali (such as ammonia) to induce a co-precipitation reaction, forming a hydroxide coprecipitate. The coprecipitate is then washed, dried, and calcined at 1450-1800℃ to convert the raw material into stable zirconia powder. 3Y zirconia contains a significant amount of t-zirconia, which readily transforms into m-zirconia under hydrothermal conditions, resulting in poor hydrothermal aging performance.

[0024] The method for preparing stable zirconia powder in this invention differs from traditional methods. This invention uses nano-monoclinic zirconia as the raw material, and adds alumina and a dispersant for co-milling. Then, Y₂O₃ is deposited on the surface of ATZ composite powder via magnetron sputtering to form stable zirconia powder. Compared to traditional preparation processes, on the one hand, the magnetron sputtering method for depositing Y₂O₃ on the surface of ATZ composite powder can inhibit the transformation of t-zirconia to m-zirconia, thus improving the anti-aging properties of zirconia ceramics. On the other hand, the direct mixing and grinding of nano-monoclinic zirconia with alumina makes the zirconia raw material more susceptible to stress-induced phase transformation, thereby improving the toughness of zirconia ceramics. Therefore, the zirconia ceramics prepared by this method show significantly improved properties, providing superior zirconia ceramic materials for the manufacture of components in medical, aerospace, chemical, and electronic devices.

[0025] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing high-toughness, aging-resistant zirconia ceramic, characterized in that, Includes the following steps: S1: Take nano-monoclinic zirconium oxide with a D50 of 20-50 nm, with a mass fraction of 99.7-99.8 wt%; alumina with a D50 of 200-400 nm, with a mass fraction of 0.2-0.3 wt%; and a dispersant, the dispersant being 1-1.5 wt% of the total powder mass. S2: Using high-purity alumina grinding balls as the grinding medium, the mixture is stirred and ground for 2-4 hours at a speed of 700-1000 r / min, and then ground for 1-2 hours at a speed of 1500-2000 r / min to obtain a mixed slurry. S3: Spray granulation of the mixed slurry to obtain uniform ATZ composite powder; S4: Y2O3 is deposited on the surface of ATZ composite powder by magnetron sputtering to a thickness of 0.01-0.03 μm to obtain uniform composite powder; S5: The composite powder obtained in S4 is dry-pressed into a green body; S6: High-toughness and aging-resistant zirconia ceramics are obtained by sintering the green blanks.

2. The method for preparing and applying a high-toughness, aging-resistant zirconia ceramic according to claim 1, characterized in that: The diameter of the high-purity alumina grinding balls in S2 is 0.2-0.4 mm.

3. The method for preparing and applying a high-toughness, aging-resistant zirconia ceramic according to claim 1, characterized in that: In S3, the spray speed is set to 15000-20000 r / min, the inlet temperature is set to 220±5℃, and the outlet temperature is set to 110℃±10℃.

4. The method for preparing and applying a high-toughness, aging-resistant zirconia ceramic according to claim 1, characterized in that: In step S5, the pressure for dry pressing is set to 200 MPa.

5. The method for preparing and applying a high-toughness, aging-resistant zirconia ceramic according to claim 1, characterized in that: In step S6, the sintering heating rate of the green embryo is set to 0.5℃ / min, sintering is carried out under a protective argon atmosphere, the temperature is set to 1500℃, and the holding time is 4h.

6. An application of a zirconia ceramic prepared using the zirconia ceramic preparation method according to any one of claims 1-5, characterized in that: The zirconia ceramics are used in the manufacture of components for medical, aerospace, chemical, and electronic devices.