A MgAlON transparent ceramic, a photocured ceramic slurry and a corresponding preparation method

Abstract

The application discloses MgAlON transparent ceramic, photocuring ceramic slurry and a corresponding preparation method, relates to the technical field of MgAlON transparent ceramic preparation, and provides a photocuring ceramic slurry preparation method of MgAlON transparent ceramic. The photocuring ceramic slurry preparation method of the application selects MgAlON powder with large particle size and small particle size for particle grading, and performs surface modification on the powder, so that the photocuring ceramic slurry with high solid content, low viscosity, good stability and dispersibility can be obtained, the ceramic green body with good compactness and uniformity can be prepared, the green body compactness is improved, and important technical support is provided for preparing the photocuring MgAlON transparent ceramic part with complex shape, high reliability and high performance. The photocuring MgAlON transparent ceramic green body is prepared by using the photocuring ceramic slurry of the application, the advantages of the photocuring forming mode can be combined, and the MgAlON transparent ceramic with high structural compactness, complex shape and good optical transmittance can be prepared.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of MgAlON transparent ceramic preparation, and particularly relates to a MgAlON transparent ceramic, a photocured ceramic slurry and a corresponding preparation method. BACKGROUND

[0002] Spinel transparent ceramics have good mechanical properties such as high strength and high hardness, and good thermal stability. In addition, due to the cubic crystal system and isotropic crystal structure of polycrystalline ceramics, the anisotropy thereof is not scattered, resulting in high transmittance of spinel transparent ceramics from ultraviolet to mid-infrared wavelengths. Therefore, spinel transparent ceramics can be applied to national defense and commercial fields, such as transparent armor, infrared windows, domes and lenses.

[0003] MgAlON transparent ceramic, as one of spinel transparent ceramics, has a relatively wide light transmission range of 0.22-6.24 μm, and has good thermal and mechanical properties. In addition, MgAlON transparent ceramic is also functionalized by doping rare earth and transition metal cations. Therefore, MgAlON is a very attractive high-performance optical element material. All these applications usually require samples with high transparency, large size and complex shape. Therefore, the forming process of MgAlON transparent ceramic is extremely important.

[0004] Additive manufacturing technology provides a technical route for the preparation of complex ceramic parts, among which photocured molding technology stands out with its fast speed and high precision. Photocured molding technology manufactures the required complex parts by layer-by-layer stacking, but due to the problems of high viscosity, low solid content and poor filling rate of the slurry, it is easy to cause defects such as pores in the formed green body, which seriously affects the subsequent debinding and sintering and the final performance of the sample. SUMMARY

[0005] The technical problem to be solved by the present application is to improve the solid content of the photocured slurry of MgAlON transparent ceramic, reduce the viscosity of the slurry, and prepare MgAlON transparent ceramic with high density and excellent optical performance.

[0006] In order to solve the above problems, the present application proposes the following technical solutions:

[0007] In a first aspect, the present application provides a preparation method of a photocured ceramic slurry of MgAlON transparent ceramic, comprising the following steps:

[0008] S1, preparing a particle size graded MgAlON powder: taking 60-90 parts by weight of a large particle size MgAlON powder and 10-40 parts by weight of a small particle size MgAlON powder to obtain a particle size graded MgAlON powder; the average particle size of the large particle size MgAlON powder is 1-2 μm, the average particle size of the small particle size MgAlON powder is 0.5-1 μm, and the particle size of the large particle size MgAlON powder is more than 1 times the particle size of the small particle size MgAlON powder;

[0009] S2, modifying the particle size graded MgAlON powder: adding 0.1-4 parts by weight of a modifier to the particle size graded MgAlON powder obtained in S1, and then adding a solvent for ball milling, drying the ball-milled powder to remove the solvent, and sieving to obtain a modified powder;

[0010] S3, preparing a photocured ceramic slurry: taking 30-90 parts by weight of the modified powder obtained in S2, 10-70 parts by weight of a resin premix, and 0.1-4 parts by weight of a photoinitiator, uniformly dispersing, and then defoaming to obtain a photocured ceramic slurry for MgAlON transparent ceramics.

[0011] Further, the modifier is at least one of stearic acid, oleic acid, ammonium polyacrylate, and γ-(methacryloyloxy)propyltrimethoxysilane.

[0012] Further, in step S2, the solvent is one or more of anhydrous ethanol, acetone, and methanol.

[0013] Further, in step S2, the grinding medium for ball milling is alumina balls, the ratio of alumina balls:solvent:powder is 2-5:1-5:1, the ball milling time is 4-12 h, and the rotation speed is 200-600 r / min.

[0014] Further, the solid content of the photocured ceramic slurry is above 45 vol%, and preferably the solid content is between 50 and 55 vol%.

[0015] Further, the photoinitiator is one or more of 2,4,6-trimethylbenzoyl-diphenyl phosphine oxide, 2,4,6-trimethylbenzoyl phenyl ethyl phosphonate, and 4-methyl benzophenone.

[0016] Further, the resin premix is one or more of ethoxylated pentaerythritol tetraacrylate, trimethylolpropane triacrylate, and 1,6-hexanediol diacrylate.

[0017] Further, in step S3, the dispersion method is mechanical stirring or ultrasonic dispersion, and the defoaming method is vacuum defoaming.

[0018] In a second aspect, the present application provides a light-cured ceramic slurry of MgAlON transparent ceramic, which is prepared by the method of the first aspect.

[0019] In a third aspect, the present application provides a method for preparing MgAlON transparent ceramic, which comprises the following steps: using the light-cured ceramic slurry of MgAlON transparent ceramic prepared by the first aspect or the light-cured ceramic slurry of MgAlON transparent ceramic of the second aspect to perform light-cured molding to prepare a green body, cleaning the surface residual slurry of the green body, and then performing debinding and sintering to prepare the MgAlON transparent ceramic.

[0020] Further, the debinding of the step S4 is a vacuum-air two-step degassing process, which comprises the following steps: first, in a vacuum degassing furnace, the temperature is raised from room temperature to 100-150℃ at a rate of 0.1-5℃ / min, and then kept for 1-2h, and then raised to 200-250℃, and kept for 1-2h, and then raised to 300-350℃, and kept for 1-2h, and finally raised to 400-600℃, and kept for 2-4h; and then, in an air degassing furnace, the temperature is raised from room temperature to 100-150℃ at a rate of 0.1-5℃ / min, and then kept for 1-2h, and then raised to 200-250℃, and kept for 1-2h, and then raised to 300-350℃, and kept for 1-2h, and finally raised to 400-600℃, and kept for 2-4h.

[0021] Further, the sintering of the step S4 is an atmosphere furnace pre-sintering-hot isostatic pressing sintering process, which comprises the following steps: the green body after debinding is first pre-sintered in an atmosphere furnace, the sintering atmosphere is nitrogen, the sintering temperature is 1700-1900℃, and the holding time is 2-4h; and the pre-sintered ceramic is subjected to hot isostatic pressing sintering at 1800-1900℃ and 150-200MPa, and the holding time is 2-4h.

[0022] Further, the sintering temperature of the atmosphere furnace pre-sintering is lower than the sintering temperature of the hot isostatic pressing sintering.

[0023] In a fourth aspect, the present application provides a MgAlON transparent ceramic, which is prepared by the method of the third aspect.

[0024] Compared with the prior art, the present application can achieve the following technical effects:

[0025] The application provides a preparation method of the MgAlON transparent ceramic photo-cured ceramic slurry, and the photo-cured ceramic slurry with high solid content, low viscosity, good stability and dispersity can be obtained by selecting the particle grading MgAlON powder and performing surface modification on the powder, which is beneficial to the preparation of the ceramic green body with good compactness and uniformity, improves the green body density, and provides important technical support for the preparation of the high-reliability and high-performance photo-cured MgAlON transparent ceramic part with a complex shape.

[0026] The MgAlON transparent ceramic photo-cured ceramic slurry is used for photo-cured forming to prepare a green body, and the MgAlON transparent ceramic with high structural density, complex shape and good optical transmittance can be prepared by combining the advantages of the photo-cured forming method. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor.

[0028] Figure 1 The SEM picture of the MgAlON ceramic prepared in the embodiment 1 of the application.

[0029] Figure 2 The picture of the MgAlON ceramic sample prepared in the embodiment 1 of the application. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments will be described clearly and completely with reference to the drawings in the embodiments of the application. Obviously, the following described embodiments are only some of the embodiments of the application, but not all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the application.

[0031] It should be understood that when used in the specification and the appended claims, the terms "comprise" and "include" indicate the presence of described features, integers, steps and / or operations, but do not exclude one or more other features, integers, steps, operations and / or sets thereof.

[0032] It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used in this specification and the appended claims, the singular forms "a," "an" and "the" include plural referents unless the content clearly dictates otherwise.

[0033] Embodiment 1

[0034] The present embodiment provides a photocured ceramic slurry of MgAlON transparent ceramic, and a method for preparing MgAlON transparent ceramic using the slurry, specifically comprising the following steps:

[0035] (1) Ceramic powder grading and surface modification: 89.1 parts of MgAlON powder with an average particle size of 1.5 μm and 9.9 parts of MgAlON powder with an average particle size of 0.5 μm were taken by weight, and particle grading was performed; 1 part of γ-methacryloxypropyltrimethoxysilane was taken together with the particle graded MgAlON powder and placed in a polytetrafluoroethylene ball mill tank containing absolute ethanol for planetary ball milling, and alumina balls were added as grinding balls. The mass ratio of balls: powder: absolute ethanol was 2:1:3, the ball milling time was 8 h, and the rotation speed was 400 r / min. After the milled powder was dried in an oven to remove the solvent, the modified powder was sieved;

[0036] (2) Preparation of photocured ceramic slurry: 78 parts of modified MgAlON powder, 21.78 parts of a resin premix liquid mixed from ethoxylated pentaerythritol tetraacrylate and trimethylolpropane triacrylate, and 0.22 parts of 2,4,6-trimethylbenzoyl phenyl phosphonic acid ethyl ester were taken by weight, uniformly dispersed with a homogenizer, and then placed in a vacuum degassing machine for 40 min to remove bubbles to obtain a particle graded photocured ceramic slurry of MgAlON transparent ceramic;

[0037] (3) Ceramic green body printing: the ceramic slurry was spread in the trough, the height of the doctor blade and the speed of the rotating disc were adjusted to make the slurry evenly spread and flatten, and the slurry was solidified layer by layer to form a green body, and the residual slurry on the surface of the green body was cleaned;

[0038] (4) Ceramic green body debinding and sintering: vacuum-air two-step degassing method was used to remove the organic matter in the ceramic green body, and the process was as follows: first, the temperature was raised from room temperature to 120℃ at a rate of 2℃ / min in the vacuum degassing furnace, and then the temperature was raised to 200℃, 300℃ and 500℃ respectively, and the temperature was kept for 1 h, 1 h and 2 h respectively; then, the temperature was raised from room temperature to 150℃ at a rate of 2℃ / min in the air degassing furnace, and then the temperature was raised to 200℃, 300℃ and 500℃ respectively, and the temperature was kept for 1 h, 1 h and 2 h respectively;

[0039] The green body after the glue is removed is pre-fired in a sintering furnace with nitrogen atmosphere, the sintering temperature is 1850℃, the holding time is 4h; then it is sintered by hot isostatic pressing, the sintering temperature is 1850℃, the pressure is 200MPa, and the holding time is 2h. Finally, the MgAlON transparent ceramic is prepared.

[0040] The performance of the sample is characterized: the viscosity of the prepared slurry is 6.2Pa·s when the shear rate is 35s -1 , the density of the obtained ceramic is 99.81%, and the maximum linear transmittance is 80%; the SEM image of the prepared MgAlON transparent ceramic sample is shown in Figure 1 , and the photo is shown in Figure 2 .

[0041] Example 2

[0042] The embodiment provides a photocured ceramic slurry of MgAlON transparent ceramic and a method for preparing MgAlON transparent ceramic by using the slurry, and specifically comprises the following steps:

[0043] (1) Ceramic powder grading and surface modification: taking MgAlON powder by weight, 89.1 parts of MgAlON powder with an average particle size of 1.5μm and 9.9 parts of MgAlON powder with an average particle size of 0.5μm are graded; 1 part of ammonium polyacrylate is taken and put into a polytetrafluoroethylene ball mill tank containing anhydrous ethanol together with the particle graded MgAlON powder to perform planetary ball milling, and alumina balls are added as grinding balls. The mass ratio of balls:powder:anhydrous ethanol is 2:1:3, the ball milling time is 8h, and the rotation speed is 400r / min. After the milled powder is dried in an oven to remove the solvent and sieved, the modified powder is obtained;

[0044] (2) Preparation of photocured ceramic slurry: by weight, 78 parts of the modified MgAlON powder, 21.78 parts of a resin premix liquid mixed from ethoxylated pentaerythritol tetraacrylate and trimethylolpropane triacrylate, and 0.22 parts of 2,4,6-trimethylbenzoyl phenyl phosphonic acid ethyl ester are uniformly dispersed by a homogenizer and then put into a vacuum defoaming machine to remove bubbles for 40min to obtain the photocured ceramic slurry of the particle graded MgAlON transparent ceramic;

[0045] (3) Ceramic green body printing: the ceramic slurry is laid in a trough, the height of the scraper and the speed of the rotating disc are adjusted to make the slurry evenly flat, and the slurry is solidified layer by layer to form a green body, and the residual slurry on the surface of the green body is cleaned;

[0046] (4) Ceramic green body debinding and sintering: The organic matter in the ceramic green body is removed by vacuum-air two-step degassing method. The process is as follows: first, in the vacuum degassing furnace, the temperature is raised from room temperature to 120℃ at a rate of 2℃ / min, and then the temperature is raised to 200℃, and then the temperature is raised to 300℃, and finally the temperature is raised to 500℃, and the temperature is kept for 2h; then in the air degassing furnace, the temperature is raised from room temperature to 150℃ at a rate of 2℃ / min, and then the temperature is raised to 200℃, and then the temperature is raised to 300℃, and finally the temperature is raised to 500℃, and the temperature is kept for 2h;

[0047] The degassed ceramic green body is pre-sintered in a sintering furnace with nitrogen atmosphere, the sintering temperature is 1850℃, and the holding time is 4h; then it is sintered by hot isostatic pressing, the sintering temperature is 1850℃, the pressure is 200MPa, and the holding time is 2h. Finally, MgAlON transparent ceramic is obtained.

[0048] The performance of the sample is characterized: the prepared slurry solid phase amount is 50vol%, the viscosity is 6.5Pa·s at a shear rate of 35s -1 , and the ceramic density is 99.76%, and the maximum linear transmittance is 79%.

[0049] Example 3

[0050] The present embodiment provides a photocured ceramic slurry of MgAlON transparent ceramic, and a method for preparing MgAlON transparent ceramic using the slurry, which specifically comprises the following steps:

[0051] (1) Ceramic powder grading and surface modification: The MgAlON powder is graded by weight, taking 69.3 parts of MgAlON powder with an average particle size of 1.5μm and 29.7 parts of MgAlON powder with an average particle size of 0.5μm; take 1 part of γ-methacryloxypropyltrimethoxysilane and put it into a polytetrafluoroethylene ball mill tank containing absolute ethanol together with the particle graded MgAlON powder, and add alumina balls as grinding balls. The mass ratio of ball: powder: absolute ethanol is 2:1:3, the ball milling time is 8h, and the rotation speed is 400r / min. After the ball milling is completed, the powder is dried in an oven to remove the solvent and then sieved to obtain the modified powder;

[0052] (2) Preparation of photocured ceramic slurry: by weight, 78 parts of modified MgAlON powder, 21.78 parts of resin premix liquid mixed from ethoxy pentaerythritol tetraacrylate and trimethylolpropane triacrylate, and 0.22 parts of 2,4,6-trimethylbenzoyl phenyl phosphonic acid ethyl ester are uniformly dispersed by a homogenizer and then put into a vacuum degassing machine for 40min to obtain the photocured ceramic slurry of particle graded MgAlON transparent ceramic;

[0053] (3) Ceramic blank printing: Ceramic slurry is spread into the material tank, the height of the scraper and the speed of the turntable are adjusted to make the slurry spread evenly and solidify layer by layer to form a blank. The residual slurry on the surface of the blank is cleaned.

[0054] (4) Degreasing and sintering of ceramic green bodies: The organic matter in the ceramic green body is removed by a two-step vacuum-air degreasing method. The process is as follows: first, the temperature is raised from room temperature to 120℃ at a rate of 2℃ / min in a vacuum degreasing furnace and held for 1 hour; then the temperature is raised to 200℃ and held for 1 hour; then the temperature is raised to 300℃ and held for 1 hour; finally the temperature is raised to 500℃ and held for 2 hours; then the temperature is raised from room temperature to 150℃ at a rate of 2℃ / min in an air degreasing furnace and held for 1 hour; then the temperature is raised to 200℃ and held for 1 hour; then the temperature is raised to 300℃ and held for 1 hour; finally the temperature is raised to 500℃ and held for 2 hours.

[0055] After debinding, the ceramic green body was pre-fired in a nitrogen-filled sintering furnace at 1850℃ for 4 hours; then subjected to hot isostatic pressing at 1850℃ and 200MPa for 2 hours. Finally, MgAlON transparent ceramic was obtained.

[0056] Performance characterization of the samples: The prepared slurry had a solid content of 50 vol%, and the shear rate was 35 s. -1 At a viscosity of 8.64 Pa·s, the resulting ceramic had a density of 99.36% and a maximum linear transmittance of 72%.

[0057] Comparative Example 1

[0058] This comparative example provides a photocurable ceramic slurry for MgAlON transparent ceramics, and a method for preparing MgAlON transparent ceramics using the slurry, specifically including the following steps:

[0059] (1) Particle size distribution and surface modification of ceramic powder: 89.1 parts by weight of MgAlON powder with an average particle size of 1.5 μm and 9.9 parts by weight of MgAlON powder with an average particle size of 0.5 μm were used for particle size distribution. One part of γ-methacryloyloxypropyltrimethoxysilane was added together with the particle-distributed MgAlON powder and placed in a polytetrafluoroethylene ball mill jar containing anhydrous ethanol for planetary ball milling. Alumina balls were added as grinding balls. The mass ratio of balls:powder:anhydrous ethanol was 2:1:3. The ball milling time was 8 hours and the rotation speed was 400 r / min. After ball milling, the powder was dried in an oven to remove the solvent and then sieved to obtain the modified powder.

[0060] (2) Light-cured ceramic slurry preparation: 75 parts by weight of modified MgAlON powder, 24.75 parts by weight of a resin premix liquid mixed from ethoxy pentaerythritol tetraacrylate and trimethylolpropane triacrylate, and 0.25 parts by weight of 2,4,6-trimethylbenzoyl phenyl ethyl phosphonate were uniformly dispersed by a homogenizer and then placed in a vacuum degassing machine for 40 min to remove bubbles to obtain a light-cured ceramic slurry of MgAlON transparent ceramic;

[0061] (3) Ceramic green body printing: The ceramic slurry was spread in the trough, the height of the scraper and the speed of the rotating disc were adjusted to make the slurry evenly spread and flatten, and the slurry was solidified layer by layer to form a green body. The residual slurry on the surface of the green body was cleaned up;

[0062] (4) Ceramic green body debinding and sintering: The organic matter in the ceramic green body was removed by vacuum-air two-step degassing method. The process was as follows: first, the temperature was raised from room temperature to 120℃ at a rate of 2℃ / min in the vacuum degassing furnace, and then the temperature was raised to 200℃, 300℃ and 500℃ respectively, and the temperature was kept for 1h, 1h and 2h respectively; then, the temperature was raised from room temperature to 150℃ at a rate of 2℃ / min in the air degassing furnace, and then the temperature was raised to 200℃, 300℃ and 500℃ respectively, and the temperature was kept for 1h, 1h and 2h respectively;

[0063] The degassed ceramic green body was pre-sintered in a sintering furnace with nitrogen atmosphere, the sintering temperature was 1850℃, and the holding time was 4h; then it was sintered by hot isostatic pressing, the sintering temperature was 1850℃, the pressure was 200MPa, and the holding time was 2h. Finally, MgAlON transparent ceramic was obtained.

[0064] The performance of the sample was characterized: the prepared slurry had a solid phase amount of 45vol%, a viscosity of 3.96Pa·s at a shear rate of 35s -1 , and a ceramic density of 99.01%, and a maximum linear transmittance of 60%.

[0065] Comparative Example 2

[0066] This comparative example provides a light-cured ceramic slurry of MgAlON transparent ceramic, and a method for preparing MgAlON transparent ceramic using the slurry, which specifically comprises the following steps:

[0067] (1) Ceramic powder surface modification: take MgAlON powder 99 parts with average particle size of 1.5 μm, γ-methacryloxypropyltrimethoxysilane 1 part by weight, put into a polytetrafluoroethylene ball mill tank containing anhydrous ethanol for planetary ball milling, and add alumina balls as grinding balls. The mass ratio of ball: powder: anhydrous ethanol is 2:1:3, the ball milling time is 8 h, and the rotation speed is 400 r / min. After ball milling, the powder is dried in an oven to remove the solvent and then sieved to obtain the modified powder;

[0068] (2) Preparation of photocurable ceramic slurry: take the modified MgAlON powder 78 parts, resin premix liquid 21.78 parts mixed from ethoxy pentaerythritol tetraacrylate and trimethylolpropane triacrylate, and 2,4,6-trimethylbenzoyl phenyl ethyl phosphonate 0.22 parts by weight, uniformly dispersed by a homogenizer, and then put into a vacuum degassing machine to remove bubbles for 40 min to obtain the photocurable ceramic slurry of MgAlON transparent ceramic;

[0069] (3) Ceramic green body printing: spread the ceramic slurry into the trough, adjust the height of the scraper and the speed of the rotating disc to make the slurry evenly spread and flatten, and then solidify layer by layer to form a green body, and clean the residual slurry on the surface of the green body;

[0070] (4) Ceramic green body debinding and sintering: the organic matter in the ceramic green body is removed by vacuum-air two-step degassing method, the process is as follows: first, in the vacuum degassing furnace, the temperature is raised from room temperature to 120℃ at a rate of 2℃ / min, and then kept for 1 h, then raised to 200℃, kept for 1 h, then raised to 300℃, kept for 1 h, and finally raised to 500℃, kept for 2 h; then in the air degassing furnace, the temperature is raised from room temperature to 150℃ at a rate of 2℃ / min, and then kept for 1 h, then raised to 200℃, kept for 1 h, then raised to 300℃, kept for 1 h, and finally raised to 500℃, kept for 2 h;

[0071] The ceramic green body after degassing is pre-sintered in a sintering furnace with nitrogen atmosphere, the sintering temperature is 1850℃, and the holding time is 4 h; then it is sintered by hot isostatic pressing, the sintering temperature is 1850℃, the pressure is 200 MPa, and the holding time is 2 h. Finally, MgAlON transparent ceramic is obtained.

[0072] The performance of the sample is characterized: the prepared slurry has a solid phase amount of 50 vol%, a viscosity of 5.64 Pa·s at a shear rate of 35 s -1 , and a ceramic density of 99.02%, and a maximum linear transmittance of 60%.

[0073] Comparative Example 3

[0074] This comparative example provides a photocurable ceramic slurry for MgAlON transparent ceramics, and a method for preparing MgAlON transparent ceramics using the slurry, specifically including the following steps:

[0075] (1) Surface modification of ceramic powder: 99 parts by weight of MgAlON powder with an average particle size of 0.5 μm and 1 part by weight of γ-methacryloyloxypropyltrimethoxysilane were placed in a polytetrafluoroethylene ball mill jar containing anhydrous ethanol for planetary ball milling. Alumina balls were added as grinding balls. The mass ratio of balls:powder:anhydrous ethanol was 2:1:3. The ball milling time was 8 hours and the rotation speed was 400 r / min. After ball milling, the powder was dried in an oven to remove the solvent and then sieved to obtain modified powder.

[0076] (2) Preparation of photocurable ceramic slurry: By weight, 78 parts of modified MgAlON powder, 21.78 parts of resin premix liquid composed of ethoxy pentaerythritol tetraacrylate and trimethylolpropane triacrylate, and 0.22 parts of ethyl 2,4,6-trimethylbenzoylphenylphosphonate were dispersed evenly in a homogenizer and then placed in a vacuum degassing machine for 40 min to obtain photocurable ceramic slurry of MgAlON transparent ceramic;

[0077] (3) Ceramic blank printing: Ceramic slurry is spread into the material tank, the height of the scraper and the speed of the turntable are adjusted to make the slurry spread evenly and solidify layer by layer to form a blank. The residual slurry on the surface of the blank is cleaned.

[0078] (4) Degreasing and sintering of ceramic green bodies: The organic matter in the ceramic green body is removed by a two-step vacuum-air degreasing method. The process is as follows: first, the temperature is raised from room temperature to 120℃ at a rate of 2℃ / min in a vacuum degreasing furnace and held for 1 hour; then the temperature is raised to 200℃ and held for 1 hour; then the temperature is raised to 300℃ and held for 1 hour; finally the temperature is raised to 500℃ and held for 2 hours; then the temperature is raised from room temperature to 150℃ at a rate of 2℃ / min in an air degreasing furnace and held for 1 hour; then the temperature is raised to 200℃ and held for 1 hour; then the temperature is raised to 300℃ and held for 1 hour; finally the temperature is raised to 500℃ and held for 2 hours.

[0079] After debinding, the ceramic green body was pre-fired in a nitrogen-filled sintering furnace at 1850℃ for 4 hours; then subjected to hot isostatic pressing at 1850℃ and 200MPa for 2 hours. Finally, MgAlON transparent ceramic was obtained.

[0080] Performance characterization of the samples: The prepared slurry had a solid content of 50 vol%, and the shear rate was 35 s. -1 At a viscosity of 12.9 Pa·s, the resulting ceramic had a density of 98.10% and a maximum linear transmittance of 45%.

[0081] From the results of the above examples and comparative examples, it can be seen that the light-cured ceramic slurry of the MgAlON transparent ceramic prepared by combining the particle grading and powder modification technology provided by the application improves the stability and dispersibility of the slurry by combining the powder surface modification and particle grading, so that the slurry has high solid content and low viscosity, which is beneficial to improve the density of the green body, and the performance of the obtained MgAlON ceramic is greatly improved.

[0082] Further, by adjusting the adding proportion of the particle grading particle size, the density of the obtained MgAlON transparent ceramic can reach 99.81%, and the maximum linear transmittance is 80%.

[0083] In the above examples, the description of each example has its own emphasis, and the parts not described in detail in a certain example can be referred to the related description of other examples.

[0084] The above is a specific embodiment of the application, but the protection scope of the application is not limited to this, and any person skilled in the art can easily think of various equivalent modifications or replacements within the technical range disclosed by the application, and these modifications or replacements should be covered in the protection scope of the application. Therefore, the protection scope of the application should be subject to the protection scope of the claims.

Claims

1. A method for preparing a photocured ceramic slurry of MgAlON transparent ceramic, characterized in that, The method comprises the following steps: S1, preparing a particle-graded MgAlON powder: taking 60-90 parts by weight of a large-particle-size MgAlON powder and 10-40 parts by weight of a small-particle-size MgAlON powder to obtain a particle-graded MgAlON powder; the average particle size of the large-particle-size MgAlON powder is 1-2 μm, the average particle size of the small-particle-size MgAlON powder is 0.5-1 μm, and the particle size of the large-particle-size MgAlON powder is more than 1 times the particle size of the small-particle-size MgAlON powder; S2, modifying the particle-graded MgAlON powder: adding 0.1-4 parts by weight of a modifier to the particle-graded MgAlON powder obtained in S1, and then adding a solvent for ball milling; after drying the ball-milled powder to remove the solvent, the modified powder is obtained by sieving; S3, preparing a photocured ceramic slurry: taking 30-90 parts by weight of the modified powder obtained in S2, 10-70 parts by weight of a resin premix, and 0.1-4 parts by weight of a photoinitiator, uniformly dispersing, and then removing bubbles to obtain a photocured ceramic slurry of MgAlON transparent ceramic with a solid content of 50-55 vol%; The modifier is at least one of stearic acid, oleic acid, ammonium polyacrylate, and γ-(methacryloyloxy)propyltrimethoxysilane.

2. The method of claim 1, wherein the transparent ceramic slurry of MgAlON ceramic is photo-cured. The photoinitiator is one or more of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2,4,6-trimethylbenzoyl phenyl ethyl phosphonate, and 4-methylbenzophenone. ​ 3. The method for preparing the photocurable ceramic slurry of MgAlON transparent ceramic as described in claim 1, characterized in that, The resin premix is one or more of ethoxy pentaerythritol tetraacrylate, trimethylolpropane triacrylate, and 1,6-hexanediol diacrylate.

4. A photo-cured ceramic slurry of MgAlON transparent ceramic, characterized in that, The MgAlON transparent ceramic is prepared by the method of any one of claims 1-3.

5. A method of producing a MgAlON transparent ceramic, characterized by, The MgAlON transparent ceramic is prepared by photocuring molding using the photocured ceramic slurry of MgAlON transparent ceramic prepared by any one of claims 1-3 or the photocured ceramic slurry of MgAlON transparent ceramic of claim 4, cleaning the surface of the green body after the photocuring molding, and then performing debinding and sintering.

6. The method of making MgAlON transparent ceramic according to claim 5, wherein, The debinding is a vacuum-air two-step degassing process, and the specific operation is as follows: first, in a vacuum degassing furnace, the temperature is raised from room temperature to 100-150 °C at a rate of 0.1-5 °C / min, and then the temperature is raised to 200-250 °C, and the temperature is maintained for 1-2 h, and then the temperature is raised to 300-350 °C, and the temperature is maintained for 1-2 h, and finally the temperature is raised to 400-600 °C, and the temperature is maintained for 2-4 h; then, in an air degassing furnace, the temperature is raised from room temperature to 100-150 °C at a rate of 0.1-5 °C / min, and then the temperature is raised to 200-250 °C, and the temperature is maintained for 1-2 h, and then the temperature is raised to 300-350 °C, and the temperature is maintained for 1-2 h, and finally the temperature is raised to 400-600 °C, and the temperature is maintained for 2-4 h.

7. The method of making MgAlON transparent ceramic according to claim 6, wherein, The sintering step is an atmosphere furnace pre-sintering-hot isostatic pressing sintering process, and the specific operation is as follows: the debound green body is pre-sintered in an atmosphere furnace, the sintering atmosphere is nitrogen, the sintering temperature is 1700-1900 DEG C, and the holding time is 2-4 h; the pre-sintered ceramic is subjected to hot isostatic pressing sintering under the condition of 1800-1900 DEG C and 150-200 MPa, and the holding time is 2-4 h; wherein the sintering temperature of the atmosphere furnace pre-sintering is lower than that of the hot isostatic pressing sintering.

8. A MgAlON transparent ceramic, characterized in that, obtained by the method of any one of claims 5-7.

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