A high-entropy transparent ceramic, its preparation method and application

Abstract

This invention belongs to the field of transparent ceramics technology, and discloses a high-entropy transparent ceramic, its preparation method, and its applications. The molecular formula of this high-entropy transparent ceramic is (Lu). x Y y Sc z Yb m Er n The ceramic, with the following properties: 0.05≤x≤0.6, 0.05≤y≤0.6, 0.05≤z≤0.6, 0.05≤m≤0.6, 0.05≤n≤0.6, and x+y+z+m+n=1, is prepared by ball milling Lu2O3 powder, Y2O3 powder, Sc2O3 powder, Yb2O3 powder, Er2O3 powder, and ZrO2 powder, followed by calcination at 800–1200℃ to form a green body, pressureless sintering at 1600–1800℃ under vacuum, annealing, and polishing. This ceramic has a relative density of over 99.5%, a transmittance of over 76% at 1000nm, and exhibits excellent optical, mechanical, corrosion-resistant, and radiation-resistant properties, making it suitable for applications in the preparation of nuclear energy window materials.

Description

Technical Field

[0001] This invention belongs to the field of transparent ceramics technology, and more specifically, relates to a high-entropy transparent ceramic, its preparation method, and its application. Background Technology

[0002] Most observation windows in nuclear reactors are made of glass, but it is brittle and has poor high-temperature resistance. Magnesium aluminum spinel has good stability at high temperatures and excellent mechanical properties, making it a promising material for nuclear reactors. In recent years, it has been considered as a window material for nuclear fusion systems, but irradiation can cause radiation damage (i.e., color centers), and its radiation resistance needs improvement.

[0003] Rare earth oxide transparent ceramics possess low neutron absorption cross-sections, high melting points, wide optical transparency regions, high mechanical strength and hardness, thermal shock resistance, and chemical corrosion resistance. High entropy was initially defined in solid solution metal alloys of five or more elements, and was later introduced into high-entropy ceramics. Since minimizing the Gibbs free energy controls the thermodynamic stability of materials, high configurational entropy can give ceramic materials greater thermodynamic stability at high temperatures. Furthermore, compared with traditional ceramic materials, high-entropy ceramics exhibit superior mechanical properties, corrosion resistance, thermal properties, and radiation resistance. However, existing high-entropy transparent ceramics require high preparation temperatures (>1850℃) or pressure sintering, and their optical properties are only of general concern, with limited reports on other properties. Summary of the Invention

[0004] To address the aforementioned technical problems, the primary objective of this invention is to provide a high-entropy transparent ceramic. This ceramic possesses excellent mechanical properties, corrosion resistance, and radiation resistance.

[0005] Another object of the present invention is to provide a method for preparing the above-mentioned high-entropy transparent ceramic.

[0006] Another object of the present invention is to provide applications of the above-mentioned high-entropy transparent ceramics.

[0007] The objective of this invention is achieved through the following technical solution:

[0008] The molecular formula of a high-entropy transparent ceramic is (Lu x Y y Sc z Yb m Er n )2O3, where 0.05≤x≤0.6, 0.05≤y≤0.6, 0.05≤z≤0.6, 0.05≤m≤0.6, 0.05≤n≤0.6, and x+y+z+m+n=1.

[0009] Preferably, the high-entropy transparent ceramic is prepared by ball milling, drying, grinding, and sieving Lu2O3 powder, Y2O3 powder, Sc2O3 powder, Yb2O3 powder, Er2O3 powder and sintering aid ZrO2 powder, followed by calcination at 800-1200℃ to obtain a mixed powder; the mixed powder is then shaped into a green body, sintered under vacuum at 1600-1800℃ without pressure, and then annealed and polished at 1000-1300℃.

[0010] Preferably, the high-entropy transparent ceramic has a relative density of 99.5% or higher, a transmittance of 76% or higher in the visible light region (1000nm), and minimal change in optical performance after irradiation.

[0011] Preferably, the particle size of the Lu2O3 powder, Y2O3 powder, Sc2O3 powder, Yb2O3 powder, and Er2O3 powder is 5-20 μm, the purity of the Lu2O3 powder, Y2O3 powder, Sc2O3 powder, Yb2O3 powder, and Er2O3 powder is 99.99% or higher, the particle size of the ZrO2 powder is 0.2-0.4 μm, and the purity of the ZrO2 powder is 99.9% or higher.

[0012] Preferably, in the ZrO2 powder, the atomic percentages of Lu, Y, Sc, Yb, and Er in Lu2O3 powder, Y2O3 powder, Y2O3 powder, Yb2O3 powder, and Er2O3 powder are 0.1–5 at.%.

[0013] Preferably, the ball milling is a planetary ball milling, with anhydrous ethanol and ZrO2 grinding balls added. The diameter of the ZrO2 grinding balls is 2-3 mm, the ball milling speed is 200-300 r / min, and the ball milling time is 20-48 h. The total mass of Lu2O3 powder, Y2O3 powder, Sc2O3 powder, Yb2O3 powder, Er2O3 powder, and ZrO2 powder, the mass ratio of anhydrous ethanol to ZrO2 grinding balls is 1:(2-4):(4-8).

[0014] The method for preparing the high-entropy transparent ceramic includes the following steps:

[0015] S1. Lu2O3 powder, Y2O3 powder, Sc2O3 powder, Yb2O3 powder, Er2O3 powder and sintering aid ZrO2 powder are ball-milled, dried, crushed and sieved, and then calcined at 800-1200℃ to obtain a mixed powder.

[0016] S2. The mixed powder is dry-pressed and then cold-isostatically pressed to obtain a green body. Under vacuum, it is sintered at 1600–1800℃ without pressure, followed by annealing at 1000–1300℃ and polishing to obtain (Lu). x Y y Sc z Yb m Er n)2O3 high-entropy transparent ceramic, wherein 0.05≤x≤0.6, 0.05≤y≤0.6, 0.05≤z≤0.6, 0.05≤m≤0.6, 0.05≤n≤0.6, and x+y+z+m+n=1.

[0017] Preferably, the drying temperature in step S1 is 60-80°C, the drying time is 12-24 hours, and the calcination time is 2-4 hours.

[0018] Preferably, the pressure of the cold isostatic pressing in step S2 is 150–300 MPa, and the holding time of the cold isostatic pressing is 5–10 min; the vacuum degree is 10. -4 ~10 -3 Pa; the heating rate is 10-15℃ / min, the pressureless sintering time is 6-24h, and the annealing time is 2-10h.

[0019] The application of the high-entropy transparent ceramic in the preparation of nuclear energy window materials.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. The (Lu) prepared by this invention x Y y Sc z Yb m Er n High-entropy transparent ceramics (2O3) have a relative density of over 99.5% and a transmittance of over 76% at 1000 nm. They possess high relative density, good optical, mechanical, corrosion-resistant, and radiation-resistant properties, and can be applied to the preparation of nuclear energy window materials.

[0022] 2. This invention employs vacuum pressureless sintering to prepare (Lu) by forming a multi-component solid solution at a relatively low temperature. x Y y Sc z Yb m Er n )2O3 high-entropy transparent ceramics, the process is simple, the production cost is low, and it is easy to achieve mass production. Detailed Implementation

[0023] The present invention will be further described below with reference to specific embodiments, but these should not be construed as limiting the invention. Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art. Unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in this technical field.

[0024] Example 1

[0025] 1. Lu2O3 powder, Y2O3 powder, Sc2O3 powder, Yb2O3 powder, and Er2O3 powder in a molar ratio of 2:3:1:2:2 were mixed with 0.5 at.% sintering aid ZrO2 powder (the atomic percentage of Lu, Y, Sc, Yb, and Er in the ZrO2 powder was 0.5 at.%). Anhydrous ethanol solvent and ZrO2 grinding balls (2 mm in diameter) were added. The total mass of Lu2O3, Y2O3, Sc2O3, Yb2O3, Er2O3 powder, and ZrO2 powder, and the mass ratio of ethanol to ZrO2 grinding balls were 1:2:6. The ball milling speed was 250 r / min, and the ball milling time was 20 h. The mixture was dried, ground, sieved, and calcined at 1000℃ for 4 h to obtain a mixed powder.

[0026] 2. After dry pressing of the mixed powder, cold isostatic pressing at 200 MPa for 5 minutes is performed to obtain a green body. -3 Under vacuum, the temperature was increased to 1300℃ at a rate of 10℃ / min, then increased to 1800℃ at a rate of 5℃ / min, held for 8 hours, and then cooled to 800℃ at a rate of 10℃ / min before furnace cooling. Annealing was then performed in air at 1200℃ for 4 hours, followed by polishing to obtain a high-entropy transparent ceramic with the molecular formula (Lu). 0.2 Y 0.3 Sc 0.1 Yb 0.2 Er 0.2 )2O3.

[0027] The (Lu) prepared in this embodiment 0.2 Y 0.3 Sc 0.1 Yb 0.2 Er 0.2 The high-entropy transparent ceramic ₂O₃ has a relative density of 99.72%, a transmittance of 78.6% at 1000 nm, a hardness of 8.5 GPa, and a toughness of 1.2 MPa·m. 1 / 2 After 18MeV proton irradiation, the transmittance of the ceramic changed little, decreasing by only 6%.

[0028] Example 2

[0029] 1. Lu₂O₃ powder, Y₂O₃ powder, Sc₂O₃ powder, Yb₂O₃ powder, and Er₂O₃ powder in a molar ratio of 2:1.5:2.5:2:2 were mixed with 2 at.% ZrO₂ powder as a calcining aid (the atomic percentage of Lu, Y, Sc, Yb, and Er in the Lu₂O₃, Y₂O₃, Sc₂O₃, Yb₂O₃, and Er₂O₃ powders was 2 at.%). Anhydrous ethanol and ZrO₂ grinding balls (3 mm in diameter) were added. The total mass of Lu₂O₃, Y₂O₃, Sc₂O₃, Yb₂O₃, Er₂O₃ powder, and ZrO₂ powder, and the mass ratio of ethanol to ZrO₂ grinding balls were 1:3:5. The ball milling speed was 300 r / min, and the milling time was 20 h. The mixture was dried, ground, and sieved. Calcination was carried out at 900℃ for 4 h to obtain a mixed powder.

[0030] 2. After dry pressing of the mixed powder, cold isostatic pressing at 250 MPa for 5 minutes is performed to obtain a green body. -4 Under vacuum, the temperature was increased to 1300℃ at a rate of 10℃ / min, then increased to 1700℃ at a rate of 5℃ / min, held for 10 hours, and then cooled to 800℃ at a rate of 10℃ / min before furnace cooling. Annealing was then performed in air at 1200℃ for 4 hours, followed by polishing to obtain a high-entropy transparent ceramic with the molecular formula (Lu). 0.2 Y 0.15 Sc 0.25 Yb 0.2 Er 0.2 )2O3.

[0031] The (Lu) prepared in this embodiment 0.2 Y 0.15 Sc 0.25 Yb 0.2 Er 0.2 The high-entropy transparent ceramic ₂O₃ has a relative density of 99.93%, a transmittance of 80.3% at 1000 nm, a hardness of 9.2 GPa, and a toughness of 1.4 MPa·m. 1 / 2 After 18MeV proton irradiation, the transmittance of the ceramic changed little, decreasing by only 5%.

[0032] Example 3

[0033] 1. Lu₂O₃ powder, Y₂O₃ powder, Sc₂O₃ powder, Yb₂O₃ powder, and Er₂O₃ powder in a molar ratio of 1.5:2.5:2.5:2:1.5 were mixed with 2 at.% ZrO₂ powder (the atomic percentage of Lu, Y, Sc, Yb, and Er in the Lu₂O₃, Y₂O₃, Sc₂O₃, Yb₂O₃, and Er₂O₃ powders was 2 at.%). Anhydrous ethanol and ZrO₂ grinding balls (2 mm in diameter) were added. The total mass of Lu₂O₃, Y₂O₃, Sc₂O₃, Yb₂O₃, Er₂O₃ powder, and ZrO₂ powder, and the mass ratio of ethanol to ZrO₂ grinding balls were 1:2:6. The ball milling speed was 280 r / min, and the milling time was 26 h. The mixture was dried, ground, and sieved. Calcination was carried out at 900℃ for 4 h to obtain a mixed powder.

[0034] 2. After dry pressing of the mixed powder, cold isostatic pressing at 300 MPa for 5 minutes is performed to obtain a green body. -3 Under vacuum, the temperature was increased to 1300℃ at a rate of 10℃ / min, then increased to 1650℃ at a rate of 5℃ / min, held for 15 hours, and then decreased to 800℃ at a rate of 10℃ / min before furnace cooling. After annealing in air at 1100℃ for 4 hours, polishing yielded a high-entropy transparent ceramic with the molecular formula (Lu). 0.25 Y 0.15 Sc 0.25 Yb 0.2 Er 0.15 )2O3.

[0035] The (Lu) prepared in this embodiment 0.25 Y 0.15 Sc 0.25 Yb 0.2 Er 0.15 The high-entropy transparent ceramic ₂O₃ has a relative density of 99.98%, a transmittance of 81.6% at 1000 nm, a hardness of 9.8 GPa, and a toughness of 1.6 MPa·m. 1 / 2 After 18MeV proton irradiation, the transmittance of the ceramic changed little, decreasing by only 3%.

[0036] Example 4

[0037] 1. Lu₂O₃ powder, Y₂O₃ powder, Sc₂O₃ powder, Yb₂O₃ powder, and Er₂O₃ powder in a molar ratio of 3:1.5:2:1.5:2 were mixed with 2 at.% ZrO₂ powder (the atomic percentage of Lu, Y, Sc, Yb, and Er in the Lu₂O₃, Y₂O₃, Sc₂O₃, Yb₂O₃, and Er₂O₃ powders was 2 at.%). Anhydrous ethanol and ZrO₂ grinding balls (2 mm in diameter) were added. The total mass of Lu₂O₃, Y₂O₃, Sc₂O₃, Yb₂O₃, Er₂O₃ powder, and ZrO₂ powder, and the mass ratio of ethanol to ZrO₂ grinding balls were 1:3:6. The ball milling speed was 250 r / min, and the milling time was 36 h. The mixture was dried, ground, and sieved. Calcination was carried out at 1000℃ for 4 h to obtain a mixed powder.

[0038] 2. After dry pressing of the mixed powder, cold isostatic pressing at 150 MPa for 5 minutes is performed to obtain a green body. -4 Under vacuum, the temperature was increased to 1300℃ at a rate of 15℃ / min, then increased to 1600℃ at a rate of 5℃ / min, held for 6 hours, and then decreased to 800℃ at a rate of 10℃ / min before furnace cooling. After annealing in air at 1200℃ for 4 hours, polishing yielded a high-entropy transparent ceramic with the molecular formula (Lu). 0.3 Y 0.15 Sc 0.2 Yb 0.15 Er 0.2 )2O3.

[0039] The (Lu) prepared in this embodiment 0.3 Y 0.15 Sc 0.2 Yb 0.15 Er 0.2 The high-entropy transparent ceramic ₂O₃ has a relative density of 99.86%, a transmittance of 79.4% at 1000 nm, a hardness of 8.9 GPa, and a toughness of 1.28 MPa·m. 1 / 2 After 18MeV proton irradiation, the transmittance of the ceramic changed little, decreasing by only 5%.

[0040] Example 5

[0041] 1. Lu₂O₃ powder, Y₂O₃ powder, Sc₂O₃ powder, Yb₂O₃ powder, and Er₂O₃ powder in a molar ratio of 3:2:1.5:1.5:2 were mixed with 1 at.% ZrO₂ powder (the atomic percentage of Lu, Y, Sc, Yb, and Er in the Lu₂O₃, Y₂O₃, Sc₂O₃, Yb₂O₃, and Er₂O₃ powders was 1 at.%). Anhydrous ethanol and ZrO₂ grinding balls (2 mm in diameter) were added. The total mass of Lu₂O₃, Y₂O₃, Sc₂O₃, Yb₂O₃, Er₂O₃ powder, and ZrO₂ powder, and the mass ratio of ethanol to ZrO₂ grinding balls were 1:2:5. The ball milling speed was 260 r / min, and the milling time was 48 h. The mixture was dried, ground, and sieved. Calcination was carried out at 1200℃ for 4 h to obtain a mixed powder.

[0042] 2. After dry pressing of the mixed powder, cold isostatic pressing at 200 MPa for 5 minutes is performed to obtain a green body. -3 Under vacuum, the temperature was increased to 1300℃ at a rate of 10℃ / min, then increased to 1700℃ at a rate of 5℃ / min and held for 20 h. The temperature was then decreased to 800℃ at a rate of 10℃ / min and cooled in the furnace. Annealing was performed in air at 1000℃ for 4 h, followed by polishing to obtain a high-entropy transparent ceramic with the molecular formula (Lu). 0.3 Y 0.2 Sc 0.15 Yb 0.15 Er 0.2 )2O3.

[0043] The (Lu) prepared in this embodiment 0.3 Y 0.2 Sc 0.15 Yb 0.15 Er 0.2 The high-entropy transparent ceramic ₂O₃ has a relative density of 99.96%, a transmittance of 80.9% at 1000 nm, a hardness of 9.4 GPa, and a toughness of 1.3 MPa·m. 1 / 2 After 18MeV proton irradiation, the transmittance of the ceramic changed little, decreasing by only 4%.

[0044] The high-entropy transparent ceramic of this invention has a relative density of 99.5% or higher, a transmittance of 76% or higher at 1000 nm, a hardness of 8.45 GPa or higher, and a toughness of 1.2 MPa·m. 1 / 2 The above results show that after 18MeV proton irradiation, the transmittance of the ceramic changes little, with a decrease of less than 6%. It has good optical, mechanical, corrosion resistance and radiation resistance properties, and can be applied to the preparation of nuclear energy window materials.

[0045] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations and simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A high-entropy transparent ceramic, characterized in that, The molecular formula of the high-entropy transparent ceramic is (Lu x Y y Sc z Yb m Er n The high-entropy transparent ceramic is made by ball milling, drying, grinding, and sieving Lu2O3 powder, Y2O3 powder, Sc2O3 powder, Yb2O3 powder, Er2O3 powder and sintering aid ZrO2 powder, and then sintering them at 8°C. The mixture is calcined at 00~1200℃ to obtain a mixed powder; the mixed powder is shaped into a green blank, which is then sintered without pressure at 1600~1800℃ under vacuum, and then annealed and polished at 1000~1300℃ to obtain the final product; the ZrO2 powder in which Zr is Lu2O3 powder, Y2O3 powder, Sc2O3 powder, Yb2O3 powder and Er2O3 powder have an atomic ratio of 0.1~5 at.%.

2. The high-entropy transparent ceramic according to claim 1, characterized in that, The high-entropy transparent ceramic has a relative density of over 99.5% and a transmittance of over 76% in the visible light region.

3. The high-entropy transparent ceramic according to claim 1, characterized in that, The particle size of the Lu2O3 powder, Y2O3 powder, Sc2O3 powder, Yb2O3 powder, and Er2O3 powder is 5~20 µm, and the purity of the Lu2O3 powder, Y2O3 powder, Sc2O3 powder, Yb2O3 powder, and Er2O3 powder is ≥99.99%. The particle size of the ZrO2 powder is 0.2~0.4 µm, and the purity of the ZrO2 powder is ≥99.9%.

4. The high-entropy transparent ceramic according to claim 1, characterized in that, The ball milling is a planetary ball milling, with anhydrous ethanol and ZrO2 grinding balls added. The diameter of the ZrO2 grinding balls is 2~3 mm, the ball milling speed is 200~300 r / min, and the ball milling time is 20~48 h. The total mass of Lu2O3 powder, Y2O3 powder, Sc2O3 powder, Yb2O3 powder, Er2O3 powder and ZrO2 powder, the mass ratio of anhydrous ethanol and ZrO2 grinding balls is 1:(2~4):(4~8).

5. The method for preparing high-entropy transparent ceramics according to any one of claims 1-4, characterized in that, Includes the following steps: S1. Lu2O3 powder, Y2O3 powder, Sc2O3 powder, Yb2O3 powder, Er2O3 powder and sintering aid ZrO2 powder are ball-milled, dried, crushed and sieved, and then calcined at 800~1200℃ to obtain a mixed powder. S2. The mixed powder is dry-pressed and then cold-isostatically pressed to obtain a green body. Under vacuum, it is sintered at 1600-1800℃ without pressure, then annealed at 1000-1300℃ and polished to obtain (Lu). x Y y Sc z Yb m Er n )2O3 high-entropy transparent ceramic, wherein 0.05≤x≤0.6, 0.05≤y≤0.6, 0.05≤z≤0.6, 0.05≤m≤0.6, 0.05≤n≤0.6, and x+y+z+m+n=1.

6. The method for preparing high-entropy transparent ceramics according to claim 5, characterized in that, The drying temperature in step S1 is 60~80℃, the drying time is 12~24h, and the calcination time is 2~4h.

7. The method for preparing high-entropy transparent ceramics according to claim 5, characterized in that, The pressure of the cold isostatic pressing in step S2 is 150~300MPa, and the holding time is 5~10min; the vacuum degree is 10. -4 ~10 -3 Pa; the heating rate is 10~15℃ / min, the pressureless sintering time is 6~24h, and the annealing time is 2~10h.

8. The application of the high-entropy transparent ceramic according to any one of claims 1-4 in the field of preparing nuclear energy window materials.