Preparation and application of a YAG ceramic slurry for photocuring.

Abstract

This invention discloses the preparation and application of a YAG ceramic slurry for photocurable molding, comprising: preparing surface-modified YAG powder; preparing a photocurable resin by sequentially adding a photoinitiator and a dispersant, stirring under light-protected conditions to obtain a photocurable resin system mixture; ball milling the surface-modified YAG powder and the photocurable resin system mixture to obtain a YAG ceramic slurry for photocurable molding; and using the YAG ceramic slurry to prepare YAG ceramic materials with a predetermined structure via photocurable 3D printing. This invention improves the dispersibility and slurry stability of YAG powder through surface modification, and effectively controls the rheological properties of the slurry by adjusting the proportions of different photocurable resins, photoinitiators, and dispersants, meeting the requirements of photocurable molding under different conditions. The relative density of the YAG ceramic material after debinding and sintering reaches 97.5%.

Description

Technical Field

[0001] This invention belongs to the field of photopolymerization 3D printing technology. More specifically, this invention relates to the preparation and application of a YAG ceramic slurry for photopolymerization molding. Background Technology

[0002] Yttrium aluminum garnet (YAG) ceramics exhibit excellent transmittance of visible and infrared light, while also possessing advantages such as high temperature resistance, high hardness, and wear resistance, making them a promising and valuable new laser material. Traditionally, YAG ceramics are prepared into green blanks using methods such as cold isostatic pressing, slip casting, and tape casting, which are then reacted and sintered in a mold. This method is complex, resulting in material waste, increased costs, and limitations in fabricating devices with complex or intricate structures.

[0003] In recent years, additive manufacturing technology has developed rapidly and has received widespread attention and importance from researchers both at home and abroad. Photopolymer 3D printing uses a laser of specific wavelength and intensity focused onto the surface of a photopolymer material, causing it to be stacked and cured layer by layer to form a pre-defined three-dimensional entity. This manufacturing technology effectively solves the problem of material waste and, with computer-aided processing, can complete the molding of devices with complex shapes or intricate structures.

[0004] Ceramic slurry is both crucial and fundamental to photopolymerization printing technology. First, the ceramic slurry needs excellent stability and dispersibility. The liquid dispersion medium must adequately wet the ceramic particles with high surface energy, stabilizing the virgin particles and other dispersed phases through electrostatic interactions or steric hindrance, preventing collisional agglomeration and gravitational sedimentation due to Brownian motion. However, high surface energy ceramic powders are difficult to disperse in low surface energy organic phases, making common ceramic slurries prone to sedimentation and resulting in uneven printing. Second, increasing the solid content of the printing slurry has always been a challenge. Simply increasing the proportion of ceramic powder leads to a dramatic increase in slurry viscosity, making it difficult to ensure leveling. Finally, printed ceramic parts require degreasing to remove organic impurities and sintering for densification. Degreasing ceramic materials in air often results in residual carbide organic impurities, and YAG ceramics are extremely sensitive to impurity content. Therefore, achieving effective degreasing and densification of ceramic printed parts has become a pressing problem to be solved. Summary of the Invention

[0005] One object of the present invention is to solve at least the above-mentioned problems and / or defects, and to provide at least the advantages described below.

[0006] To achieve these objectives and other advantages of the present invention, a method for preparing a YAG ceramic slurry for photocuring is provided, comprising the following steps:

[0007] Step 1: Prepare surface-modified YAG powder. The specific method is as follows:

[0008] S11. Mix anhydrous ethanol and modifier, sonicate and stir to obtain modifier solution;

[0009] S12. Add YAG powder to the modifier solution, ball mill and mix to obtain a mixture;

[0010] S13. Dry the mixture obtained in S2, grind and sieve it to obtain surface-modified YAG powder;

[0011] Step 2: Prepare the photocurable resin by adding the photoinitiator and dispersant in sequence and stirring under light-protected conditions to obtain a photocurable resin system mixture.

[0012] Step 3: Mix and ball-mill the surface-modified YAG powder and the photocurable resin system mixture to obtain YAG ceramic slurry for photocuring.

[0013] Preferably, in step one, the modifier is at least one of sebacic acid and glutaric acid; the concentration of the modifier solution is 0.1-1.0 wt%; sonication is performed for 2-5 min, and stirring is performed for 0.5-1.5 h.

[0014] Preferably, in step one, the mass ratio of YAG powder to modifier solution is 1 to 3:1; the specific parameters for ball milling are: rotation speed 200 to 400 r / min, clockwise ball milling for 20 minutes and stopping for 15 minutes, then counterclockwise ball milling for 20 minutes and stopping for 15 minutes, ball-to-material ratio 2 to 5:1, and ball milling for 6 to 10 hours.

[0015] Preferably, in step one, the drying is carried out at a constant temperature of 50-70°C until the anhydrous ethanol is completely evaporated; and the material is ground through a 300-500 mesh sieve.

[0016] Preferably, in step two, the preparation of the photocurable resin specifically involves mixing 1,6-hexanediol diacrylate (HDDA), hydroxyethyl acrylate (HEA), and trimethylolpropane triacrylate (TMPTA) at a mass ratio of 5–7:2–4:1, and magnetically stirring under light-protected conditions for 2–4 hours to obtain the photocurable resin.

[0017] Preferably, in step two, the photoinitiator is 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (TPO), and the amount used is 1 wt% of the mass of the photocurable resin.

[0018] Preferably, in step two, the dispersant is at least one of KH550 and KOS110, and the amount of dispersant added is 5 wt% based on the mass of the surface-modified YAG powder in step three.

[0019] Preferably, in step two, the mixture is stirred for 0.5 to 1.5 hours under light-protected conditions.

[0020] Preferably, in step three, the volume ratio of the surface-modified YAG powder to the photocurable resin system mixture is 40-50:50-60; the specific parameters for ball milling are: rotation speed 200-400 r / min, ball-to-material ratio 2-5:1, and ball milling for 3-7 hours.

[0021] Preferably, in step one, the method for preparing surface-modified YAG powder is replaced by:

[0022] S11. Mix anhydrous ethanol and sebacic acid, sonicate for 2-5 minutes, and then magnetically stir for 0.5-1.5 hours to prepare a sebacic acid solution with a mass fraction of 0.1-1.0 wt%.

[0023] S12. Mix anhydrous ethanol, polyethylene glycol-200 and KH550, sonicate for 2-5 min and then magnetically stir for 0.5-1.5 h. Add acetic acid to adjust the pH to 4-6 to obtain a second solution. In the second solution, the mass fraction of polyethylene glycol-200 is 0.1-0.5 wt% and the mass fraction of KH550 is 0.1-0.5 wt%.

[0024] S13. Add YAG powder to sebacic acid solution at a mass ratio of 1–3:1, and ball mill for 6–10 hours. Add the resulting product to a second solution at a mass ratio of 1:1–2, place the solution between two copper electrodes, apply alternating current to the electrodes, and treat with an alternating electric field for 20–60 minutes to obtain a second mixture. The specific ball milling parameters are: ball-to-material ratio 2–5:1, rotation speed 200–400 r / min, first ball mill clockwise for 20 minutes with a 15-minute pause, then ball mill counterclockwise for 20 minutes with a 15-minute pause, and repeat this cycle. The specific alternating electric field parameters are: voltage amplitude 50–200V, frequency 100–400Hz, and waveform either sawtooth or sine wave.

[0025] S14. The second mixture is dried at a constant temperature of 50-70℃ until the anhydrous ethanol is completely evaporated, and then ground through a 300-500 mesh sieve to obtain surface-modified YAG powder.

[0026] An application of a YAG ceramic slurry prepared by the method described above for photopolymerization molding, wherein the YAG ceramic slurry is used to prepare YAG ceramic materials with a predetermined structure by photopolymerization 3D printing, comprising the following steps:

[0027] S1. Place the YAG ceramic slurry for photopolymerization into the photopolymerization 3D printer and print layer by layer according to the preset three-dimensional model. Each layer is formed by photopolymerization. The thickness of a single layer is 50-100μm and the curing time of a single layer is 5-15s, resulting in a printed blank with the preset structure.

[0028] S2. After drying the printed preform obtained in S1, it is placed in isopropanol and sonicated for 3-8 minutes, then placed in anhydrous ethanol and sonicated for 5-15 minutes. After taking it out, it is irradiated under ultraviolet light for 10-14 hours to obtain the photocured printed preform.

[0029] S3. Degrease the photocured printed green body to obtain a degreased YAG ceramic green body;

[0030] S4. The degreased YAG ceramic blank is sintered to obtain YAG ceramic material.

[0031] Preferably, in step S3, the specific method for degreasing is as follows: the photocured printed green body is placed in a tube furnace, and under vacuum conditions, the temperature is increased from room temperature to 150-250℃ at a rate of 1-3℃ / min and held for 80-100 min, then increased to 200-300℃ and held for 80-100 min, then increased to 250-350℃ and held for 80-100 min, so that the organic matter in the green body is fully pyrolyzed, and finally the temperature is held at 500-700℃ for 100-200 min and then cooled with the furnace to obtain the degreased YAG ceramic green body.

[0032] Preferably, in step S4, the specific sintering method is as follows: the degreased YAG ceramic green body is placed in a high-temperature sintering furnace, and a small amount of chromatographic alumina is placed at the bottom of the crucible to prevent the YAG ceramic green body from sticking to the crucible at high temperature. The temperature is increased from room temperature to 1300-1500℃ at a rate of 5-15℃ / min and held for 100-140min. The temperature is then increased to 1500-1700℃ at a rate of 2-7℃ / min, and then increased to 1600-1800℃ at a rate of 1-3℃ / min and held for 250-350min to allow the grains to grow fully and the pores to be expelled, thereby making the ceramic dense. Finally, the temperature is decreased to 1100-1300℃ at a rate of 3-5℃ / min. After it stabilizes, it is cooled to room temperature with the furnace to obtain the YAG ceramic material.

[0033] The present invention has at least the following beneficial effects:

[0034] 1) This invention prepares photocurable ceramic slurry from yttrium aluminum garnet (YAG) ceramic powder by mechanical stirring and ball milling, providing a simple and scalable method for producing YAG ceramic materials. The slurry preparation process is simple, has high stability and high solid content, and the solvent and crosslinking agent in the printed parts are easy to remove, effectively ensuring the mechanical properties of the YAG ceramic materials.

[0035] 2) The YAG ceramic slurry prepared by this invention has excellent performance and stable properties. Its viscosity can be adjusted within a certain range according to printing requirements by adjusting the solid content and additive ratio, and it has a wide range of applications.

[0036] 3) This invention uses dicarboxylic acid to modify the surface of YAG ceramic powder, which improves the dispersibility and slurry stability of YAG ceramic powder. By adjusting the proportions of different photocurable resins, photoinitiators, and dispersants, the rheological properties of the slurry can be effectively controlled to meet the requirements of photocuring under different conditions. After debinding and sintering, the relative density of the printed YAG ceramic can reach 97.5%.

[0037] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0038] Figure 1 Viscosity curve of the YAG ceramic slurry prepared in Example 1;

[0039] Figure 2 A viscosity comparison graph showing the YAG ceramic slurry prepared in Example 2 and Comparative Example 1;

[0040] Figure 3 This is a comparison diagram of the relative densities of the photocured printed preform, the degreased YAG ceramic preform, and the sintered YAG ceramic material in Example 3;

[0041] Figure 4 The viscosity curve of the YAG ceramic slurry prepared in Example 4 is shown.

[0042] Figure 5 The viscosity curve of the YAG ceramic slurry prepared in Example 5 is shown. Detailed Implementation

[0043] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0044] It should be understood that terms such as “having,” “comprising,” and “including” as used herein do not exclude the presence or addition of one or more other elements or combinations thereof.

[0045] Example 1

[0046] A method for preparing YAG ceramic slurry for photocuring includes the following steps:

[0047] Step 1: Preparation of surface-modified YAG powder:

[0048] S11. Add anhydrous ethanol and glutaric acid to a beaker, sonicate for 3 minutes and then stir magnetically for 1 hour to prepare a glutaric acid solution with a mass fraction of 0.5 wt%.

[0049] S12. Add YAG powder to glutaric acid solution at a mass ratio of 2:1 and mix using a ball mill for 8 hours to obtain a mixture. The specific ball milling parameters are: ball-to-powder ratio of 3:1, rotation speed of 300 r / min, first ball mill clockwise for 20 minutes and stop for 15 minutes, then ball mill counterclockwise for 20 minutes and stop for 15 minutes, and so on.

[0050] S13. Place the mixture obtained in step S12 in an oven and dry it at a constant temperature of 60°C until the anhydrous ethanol is completely evaporated. Grind it through a 400-mesh sieve to obtain surface-modified YAG powder.

[0051] Step 2: Preparation of UV-curable resin: Mix 1,6-hexanediol diacrylate, hydroxyethyl acrylate and trimethylolpropane triacrylate in a mass ratio of 6:3:1 and stir magnetically for 3 hours under light-protected conditions to obtain UV-curable resin;

[0052] Step 3: Add photoinitiator TPO and dispersant KOS110 to the above-mentioned photocurable resin in sequence, and stir magnetically for 1 hour under light-proof conditions to obtain a photocurable resin system mixture; wherein, the photoinitiator is 1 wt% of the mass of the photocurable resin, and the dispersant is 5 wt% of the mass of the surface-modified YAG powder.

[0053] Step 4: Take the surface-modified YAG powder and the photocurable resin mixture at a volume ratio of 45 vol%:55 vol% and pour them into a ball mill jar. Mix them in a ball mill at a ball-to-powder ratio of 3:1 for 5 hours at a speed of 300 r / min to obtain a YAG ceramic slurry for photocuring (viscosity <50 Pa·s). Its viscosity curve is shown in the figure. Figure 1 As shown, with the increase of shear rate, the viscosity of YAG ceramic slurry gradually decreases from 30.53 Pa·s to 1.43 Pa·s.

[0054] Example 2

[0055] In this embodiment, sebacic acid is used instead of glutaric acid, and the remaining steps are the same as in Example 1, to obtain a YAG ceramic slurry (viscosity < 10 Pa·s) for photocuring.

[0056] Comparative Example 1

[0057] In this comparative example, YAG ceramic slurry was prepared using unmodified YAG powder, and the remaining steps were the same as in Example 1, including the following steps:

[0058] Step 1: Preparation of UV-curable resin: Mix 1,6-hexanediol diacrylate, hydroxyethyl acrylate and trimethylolpropane triacrylate in a mass ratio of 6:3:1 and stir magnetically for 3 hours under light-protected conditions to obtain UV-curable resin;

[0059] Step 2: Add photoinitiator TPO and dispersant KOS110 to the above-mentioned photocurable resin in sequence, and stir magnetically for 1 hour under light-proof conditions to obtain a photocurable resin system mixture; wherein, the photoinitiator is 1 wt% of the mass of the photocurable resin, and the dispersant is 5 wt% of the mass of YAG powder.

[0060] Step 3: Weigh out the YAG powder and the photocurable resin mixture at a volume ratio of 45 vol%: 55 vol% and pour them into a ball mill jar. Mix them in a ball mill at a ball-to-powder ratio of 3:1 for 5 hours at a speed of 300 r / min to obtain a YAG ceramic slurry (viscosity > 50 Pa·s) for photocuring.

[0061] Figure 2 The viscosity curves of the YAG ceramic slurries prepared in Example 2 and Comparative Example 1 show that the YAG ceramic slurry prepared in Example 2 using YAG powder with sebacic acid surface modification has a lower viscosity. As the shear rate increases, the viscosity of the YAG ceramic slurry prepared in Example 2 decreases from 6.57 Pa·s to 0.17 Pa·s, and the viscosity of the YAG ceramic slurry prepared in Comparative Example 1 decreases from 51.97 Pa·s to 2.99 Pa·s.

[0062] Example 3

[0063] An application of a YAG ceramic slurry for photocuring includes the following steps:

[0064] Step 1: Place the YAG ceramic slurry obtained in Example 1 into a 430nm wavelength photopolymerization 3D printer and print it according to the sliced ​​three-dimensional model. The first layer is formed by photopolymerization, with a single layer thickness of 50μm and a single layer curing time of 10s. Then, use the printer's scraper to cover the remaining slurry on the first layer and form the second layer by photopolymerization. By continuously repeating the above steps, the printed blank is gradually formed to form the predetermined structure.

[0065] Step 2: After drying the printed blank obtained in Step 1, place it in isopropanol and sonicate for 5 minutes, then place it in anhydrous ethanol and sonicate for 10 minutes. Remove it and irradiate it under a UV lamp for 12 hours to obtain a photocured printed blank with a relative density of 56.2%.

[0066] Step 3: Place the photocured printed green body into a vacuum tube furnace for degreasing: Evacuate and fill with inert gas, repeat three times to remove air, then heat from room temperature to 200℃ at a rate of 1℃ / min under vacuum conditions and hold for 90 min, then heat to 250℃ and hold for 90 min, then heat to 300℃ and hold for 90 min to fully pyrolyze the organic matter in the green body, and finally heat to 600℃ for 150 min and cool with the furnace to obtain the degreased YAG ceramic green body with a relative density of 80.3%;

[0067] Step 4: Place the degreased YAG ceramic green body from Step 3 into a high-temperature sintering furnace. Place a small amount of chromatographic alumina at the bottom of the crucible to prevent the YAG ceramic green body from sticking to the crucible at high temperature. Heat from room temperature to 1400℃ at a heating rate of 10℃ / min, hold for 120min, then heat to 1600℃ at a rate of 5℃ / min, and then heat to 1700℃ at a rate of 2℃ / min and hold for 300min to allow the grains to grow fully and the pores to be expelled, thereby making the ceramic dense. Finally, cool to 1200℃ at a rate of 4℃ / min and let it stabilize before cooling to room temperature with the furnace to obtain the YAG ceramic material with a relative density of 97.5%.

[0068] Figure 3 This is a comparison diagram of the relative densities of the photocured YAG ceramic preform, the degreased YAG ceramic preform, and the sintered YAG ceramic material in this embodiment.

[0069] Example 4

[0070] This embodiment provides a method for preparing YAG ceramic slurry for photocuring, only changing the preparation method of surface-modified YAG powder; the remaining steps are the same as in Example 1. The preparation method of surface-modified YAG powder is as follows:

[0071] S11. Add anhydrous ethanol and sebacic acid to a beaker, sonicate for 3 minutes and then stir magnetically for 1 hour to prepare a sebacic acid solution with a mass fraction of 0.5 wt%.

[0072] S12. Add anhydrous ethanol, polyethylene glycol-200 and KH550 to a beaker, sonicate for 3 min and then stir magnetically for 1 h. Add acetic acid to adjust the pH to 6 to obtain the second solution. In the second solution, the mass fraction of polyethylene glycol-200 is 0.3 wt% and the mass fraction of KH550 is 0.2 wt%.

[0073] S13. YAG powder is added to sebacic acid solution at a mass ratio of 2:1. The mixture is then milled in a ball mill for 8 hours. The resulting product is added to a second solution at a mass ratio of 1:1. The mixture is then placed between two copper electrodes, and an alternating current is applied to the electrodes. The mixture is then treated with an alternating electric field for 30 minutes to obtain the second mixture. The specific parameters for the ball milling are: ball-to-material ratio 3:1, rotation speed 300 r / min, clockwise milling for 20 minutes followed by a 15-minute pause, then counterclockwise milling for 20 minutes followed by a 15-minute pause, and this cycle is repeated. The specific parameters for the alternating electric field are: voltage amplitude 100V, frequency 200Hz, and sawtooth waveform.

[0074] S14. Place the second mixture in an oven and dry it at a constant temperature of 60°C until the anhydrous ethanol is completely evaporated. Grind it through a 400-mesh sieve to obtain surface-modified YAG powder.

[0075] In this embodiment, sebacic acid, polyethylene glycol-200, and KH550 were used as modifiers to modify the surface of YAG powder. This reduced the surface energy of the powder, decreased the friction between particles, and provided greater steric hindrance. The use of an alternating electric field to treat the mixture improved the uniformity of powder particle size, promoted the coordination and bonding of the modifier with the YAG powder, resulting in more complete and uniform coating of the YAG powder, promoting surface modification, preventing collisions and agglomeration between powder particles, improving its dispersibility, and further reducing the viscosity of the YAG ceramic slurry. Under the same solid content, the viscosity of the YAG ceramic slurry prepared in Example 4 was lower than that in Examples 1 and 2. Figure 4 As shown, with the increase of shear rate, the viscosity of the YAG ceramic slurry prepared in Example 4 decreased from 5.02 Pa·s to 0.05 Pa·s.

[0076] Example 5

[0077] This embodiment provides a method for preparing YAG ceramic slurry for photocuring. In preparing the surface-modified YAG powder, no alternating electric field treatment is used. The remaining steps are the same as in Example 4. The method for preparing the surface-modified YAG powder is as follows:

[0078] S11. Add anhydrous ethanol and sebacic acid to a beaker, sonicate for 3 minutes and then stir magnetically for 1 hour to prepare a sebacic acid solution with a mass fraction of 0.5 wt%.

[0079] S12. Add anhydrous ethanol, polyethylene glycol-200 and KH550 to a beaker, sonicate for 3 min and then stir magnetically for 1 h. Add acetic acid to adjust the pH to 6 to obtain the second solution. In the second solution, the mass fraction of polyethylene glycol-200 is 0.3 wt% and the mass fraction of KH550 is 0.2 wt%.

[0080] S13. According to the mass ratio of YAG powder to sebacic acid solution of 2:1, YAG powder is added to sebacic acid solution and mixed in a ball mill for 8 hours. The resulting product is added to the second solution at a mass ratio of 1:1 and stirred for 30 minutes to obtain the second mixture. The specific ball milling parameters are: ball-to-material ratio of 3:1, rotation speed of 300 r / min, first ball milling clockwise for 20 minutes and then stopping for 15 minutes, then ball milling counterclockwise for 20 minutes and then stopping for 15 minutes, and so on.

[0081] S14. Place the second mixture in an oven and dry it at a constant temperature of 60°C until the anhydrous ethanol is completely evaporated. Grind it through a 400-mesh sieve to obtain surface-modified YAG powder.

[0082] like Figure 5 As shown, with the increase of shear rate, the viscosity of the YAG ceramic slurry prepared in Example 5 decreased from 5.76 Pa·s to 0.12 Pa·s.

[0083] Example 6

[0084] This embodiment provides a method for preparing YAG ceramic slurry for photocuring. The volume ratio of the surface-modified YAG powder and the photocuring resin system mixture in step three is changed to 50 vol%: 50 vol%, that is, the solid content is increased to 50 vol%. The remaining steps are the same as in embodiment 4, and a YAG ceramic slurry (viscosity < 10 Pa·s) for photocuring is obtained.

[0085] Example 7

[0086] In this embodiment, the YAG ceramic slurry obtained in Example 6 was used for photopolymerization 3D printing, and the remaining steps were the same as in Example 3, resulting in YAG ceramic material with a relative density of 98.8%.

[0087] The solid content of the printing paste affects its printing performance, green body density, and mechanical properties. Simply increasing the proportion of ceramic powder will lead to a sharp increase in paste viscosity, making it difficult to guarantee rheological properties. Increasing the solid content while maintaining the rheological properties of the paste can reduce the proportion of organic matter. This can avoid problems such as green body cracking caused by the pyrolysis and volatilization of organic matter during the subsequent debinding and sintering process of the ceramic green body, thus ensuring the density and mechanical properties of the ceramic green body. In Example 6, the solid content was increased to 50 vol%, and the prepared YAG ceramic paste still had low viscosity (<10 Pa·s) and could be used for photopolymerization 3D printing. The relative density of the YAG ceramic material obtained in Example 7 reached 98.8%.

[0088] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A method for preparing YAG ceramic slurry for photocuring, characterized in that, Includes the following steps: Step 1: Prepare surface-modified YAG powder. The specific method is as follows: S11. Mix anhydrous ethanol and sebacic acid, sonicate for 2-5 minutes, and then magnetically stir for 0.5-1.5 hours to prepare a sebacic acid solution with a mass fraction of 0.1-1.0 wt%. S12. Mix anhydrous ethanol, polyethylene glycol-200, and KH550, sonicate for 2-5 minutes, then magnetically stir for 0.5-1.5 hours. Add acetic acid to adjust the pH to 4-6 to obtain a second solution. In the second solution, the mass fraction of polyethylene glycol-200 is 0.1-0.5 wt%, and the mass fraction of KH550 is 0.1-0.5 wt%. S13. According to the mass ratio of YAG powder to sebacic acid solution of 1~3:1, add YAG powder to sebacic acid solution and ball mill for 6~10 hours. Add the obtained product to the second solution at a mass ratio of 1:1~2, place it between two copper electrodes, apply alternating current to the two copper electrodes, and treat with an alternating electric field for 20~60 minutes to obtain the second mixture. The specific parameters of ball milling are: ball-to-material ratio of 2~5:1, rotation speed of 200~400 r / min, first ball mill clockwise for 20 minutes and stop for 15 minutes, then ball mill counterclockwise for 20 minutes and stop for 15 minutes, and repeat this cycle. The specific parameters of alternating electric field are: voltage amplitude of 50~200V, frequency of 100~400Hz, and waveform of sawtooth wave or sine wave. S14. The second mixture is dried at a constant temperature of 50~70℃ until the anhydrous ethanol is completely evaporated, and then ground through a 300~500 mesh sieve to obtain surface-modified YAG powder. Step 2: Mix 1,6-hexanediol diacrylate, hydroxyethyl acrylate, and trimethylolpropane triacrylate at a mass ratio of 5-7:2-4:1, and magnetically stir for 2-4 hours under light-protected conditions to obtain a photocurable resin. Add a photoinitiator and a dispersant sequentially, and stir for 0.5-1.5 hours under light-protected conditions to obtain a photocurable resin mixture. The photoinitiator is 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, used at 1 wt% of the photocurable resin mass; the dispersant is KOS110, used at 5 wt% of the surface-modified YAG powder mass. Step 3: Mix and ball-mill the surface-modified YAG powder and the photocurable resin system mixture to obtain YAG ceramic slurry for photocuring.

2. The method for preparing YAG ceramic slurry for photocuring as described in claim 1, characterized in that, In step three, the volume ratio of the surface-modified YAG powder to the photocurable resin system mixture is 40~50:50~60; the specific parameters for ball milling are: rotation speed 200~400 r / min, ball-to-material ratio 2~5:1, and ball milling for 3~7 h.

3. An application of a YAG ceramic slurry for photocuring prepared by the preparation method according to any one of claims 1-2, characterized in that, The YAG ceramic slurry is used to prepare YAG ceramic materials with a pre-defined structure by photopolymerization 3D printing, including the following steps: S1. Place the YAG ceramic slurry for photopolymerization into the photopolymerization 3D printer and print layer by layer according to the preset three-dimensional model. The thickness of a single layer is 50~100μm and the curing time of a single layer is 5~15s, to obtain a printed blank with the preset structure. S2. After drying the printed preform obtained in S1, place it in isopropanol and sonicate for 3-8 minutes, then place it in anhydrous ethanol and sonicate for 5-15 minutes. Remove it and irradiate it under ultraviolet light for 10-14 hours to obtain the photocured printed preform. S3. Degrease the photocured printed green body to obtain a degreased YAG ceramic green body; S4. The degreased YAG ceramic blank is sintered to obtain YAG ceramic material.

4. The application of the YAG ceramic slurry for photocuring as described in claim 3, characterized in that, In S3, the specific method for degreasing is as follows: the photocured printed green body is placed in a tube furnace, and under vacuum conditions, the temperature is increased from room temperature to 150-250℃ at a rate of 1-3℃ / min and held for 80-100min, then increased to 200-300℃ and held for 80-100min, then increased to 250-350℃ and held for 80-100min, and finally held at 500-700℃ for 100-200min and cooled with the furnace to obtain the degreased YAG ceramic green body.

5. The application of the YAG ceramic slurry for photocuring as described in claim 3, characterized in that, In step S4, the specific sintering method is as follows: the degreased YAG ceramic blank is placed in a high-temperature sintering furnace, and a small amount of chromatographic alumina is placed at the bottom of the crucible to prevent the YAG ceramic blank from sticking to the crucible at high temperature. The temperature is increased from room temperature to 1300-1500℃ at a rate of 5-15℃ / min, held for 100-140min, increased to 1500-1700℃ at a rate of 2-7℃ / min, increased to 1600-1800℃ at a rate of 1-3℃ / min, held for 250-350min, and finally decreased to 1100-1300℃ at a rate of 3-5℃ / min. The material is then cooled to room temperature in the furnace to obtain the YAG ceramic material.

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