Photocuring 3D printing high-precision ceramic core and preparation method thereof

Abstract

The invention relates to a photocuring 3D printing high-precision ceramic core and a preparation method thereof, and relates to the technical field of additive manufacturing ceramic materials. The preparation method of the photocuring 3D printing ceramic core comprises the following steps: preparing a photocuring ceramic slurry from ceramic mixed powder, photocuring resin, a dispersing agent and an initiator; wherein the ceramic mixed powder is prepared from the following components in percentage by mass: 60 to 90 weight percent of framework powder, 5 to 25 weight percent of filler and 5 to 15 weight percent of shrinkage compensation agent; wherein the shrinkage compensation agent is selected from one or more of kyanite, sillimanite and andalusite; the photocuring ceramic slurry is subjected to photocuring 3D printing treatment, and a photocuring ceramic core biscuit is obtained; and sequentially carrying out degreasing treatment and sintering treatment on the photocuring ceramic core biscuit to obtain the photocuring 3D printing ceramic core. According to the invention, the bending strength of the ceramic core can be improved while the small sintering shrinkage rate of the ceramic core is ensured to improve the dimensional precision of the ceramic core.

Description

Technical Field

[0001] The present invention relates to the technical field of additive manufacturing ceramic materials, and in particular to a photocuring 3D printing high-precision ceramic core and a preparation method thereof. Background Art

[0002] As an important transitional component in the production of hollow turbine blades, ceramic cores are widely used to form complex internal air cooling channels of hollow turbine blades. With the continuous improvement of the thrust-to-weight ratio of aircraft engines, the temperature of the turbine inlet continues to rise, which poses a huge challenge to the temperature resistance of turbine blades and requires the structure of ceramic cores to be more and more complex. The traditional hot injection process is gradually unable to meet the preparation requirements of ceramic cores with complex structures.

[0003] Compared with the hot injection process, the technology of preparing ceramic cores by photocuring 3D printing technology has the advantage of not requiring molds, which makes the preparation and development of ceramic cores with complex structures more cost-effective and efficient. Among them, the photocuring 3D printing ceramic core slurry is composed of solid-phase ceramic powder and liquid-phase photocuring resin. The function of the photocuring resin is to bond the ceramic particles and shape them. However, the removal of the photocuring resin at high temperature during the degreasing process will inevitably produce a large number of pores. In the subsequent high-temperature sintering process, the ceramic core will undergo a large sintering shrinkage, which seriously affects the dimensional accuracy of the ceramic core, resulting in deformation or cracking of the complex structure ceramic core, which greatly limits the further application of ceramic cores in the aviation industry.

[0004] In order to reduce the sintering shrinkage of ceramic cores, improve the dimensional accuracy of ceramic cores, and improve the deformation and cracking problems of complex structure ceramic cores, the current method is mainly through the design of ceramic particle size distribution, optimization of degreasing and sintering process parameters, and the addition of sintering inhibitors. However, due to the complexity of the degreasing and sintering process, the change in the particle size of ceramic particles will lead to a change in the sintering driving force, and the phase change and organizational changes that occur during the sintering process are difficult to control. In addition, the result of inhibiting sintering shrinkage often leads to a significant reduction in mechanical strength.

[0005] Therefore, there is an urgent need for a method for preparing a photocurable 3D printed ceramic core, which can ensure a small sintering shrinkage rate of the ceramic core while improving the bending strength of the ceramic core. Summary of the invention

[0006] In view of this, the present invention provides a photocuring 3D printed high-precision ceramic core and a preparation method thereof, the main purpose of which is to ensure a smaller sintering shrinkage rate of the ceramic core to improve the dimensional accuracy of the ceramic core while also improving the bending strength of the ceramic core.

[0007] In order to achieve the above object, the present invention mainly provides the following technical solutions:

[0008] On the one hand, an embodiment of the present invention provides a method for preparing a high-precision ceramic core by photocuring 3D printing, which comprises the following steps:

[0009] Preparation of photocurable ceramic slurry: preparing a ceramic mixed powder, a photocurable resin, a dispersant and an initiator into a photocurable ceramic slurry; wherein, in terms of mass percentage, the ceramic mixed powder comprises 60-90wt% of a skeleton powder, 5-25wt% of a filler, and 5-15wt% of a shrinkage compensating agent; wherein the shrinkage compensating agent is selected from one or more of kyanite, sillimanite and andalusite;

[0010] Photocuring 3D printing process: performing photocuring 3D printing process on the photocuring ceramic slurry to obtain a photocuring ceramic core blank;

[0011] Degreasing and sintering treatment: The photocuring ceramic core blank is subjected to degreasing treatment and sintering treatment in sequence to obtain a photocuring 3D printing high-precision ceramic core.

[0012] Preferably, the step of preparing the light-cured ceramic slurry comprises:

[0013] 1) mixing skeleton powder, filler and shrinkage compensating agent to obtain ceramic mixed powder; mixing photocurable resin and dispersant in a volume ratio of (5-11): (1-3) to obtain photocurable resin premix;

[0014] 2) mixing the ceramic mixed powder with the photocurable resin premix to obtain a ceramic slurry with a solid content of 40-65 vol.%; then adding an initiator to the ceramic slurry and stirring to obtain a photocurable ceramic slurry;

[0015] 3) performing ball milling and vacuum degassing treatment on the photocurable ceramic slurry in sequence;

[0016] Preferably, the vacuum degassing treatment time is 3-5min;

[0017] Preferably, the ball milling time is 2-3h;

[0018] Preferably, in the ball milling process, the mass ratio of the grinding balls to the photocurable ceramic slurry is (2-6): (1-5);

[0019] Preferably, during the ball milling process, the rotation speed of the ball mill is 250-600 r / min.

[0020] Preferably, the mass of the photoinitiator is 0.01-0.4% of the mass of the ceramic slurry.

[0021] Preferably, the shrinkage compensating agent is a powder with a particle size of 5-35 μm.

[0022] Preferably, the skeleton powder is selected from one or two of Al2O3 and SiO2; and / or the particle size of the skeleton powder is 4-70μm; and / or the filler is selected from one or two of ZrO2 and ZrSiO4; and / or the particle size of the filler is 0.1-1μm.

[0023] Preferably, the photocurable resin is selected from one or more of 1,6-hexanediol diacrylate, ethoxylated bisphenol A diacrylate, 1,1,1 trimethylolpropane triacrylate, ethoxylated pentaerythritol tetraacrylate, propoxylated glycerol triacrylate, and trimethylolpropane triacrylate; and / or the dispersant is one or more of BYK111, BYK180, BYK9076, BYKW969, BYK151, and BYK2000; and / or the photoinitiator is one or two of phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide, benzoin diethyl ether, and (2,4,6-trimethylbenzoyl)-diphenylphosphine oxide.

[0024] Preferably, in the step of the light-curing 3D printing process, the process parameters of the light-curing 3D printing process are controlled as follows: the curing thickness is 100-220 μm, the curing power is 2-10 mW / cm 2 , the single layer curing time is 4-7s.

[0025] Preferably, the degreasing step comprises: heating the light-cured ceramic core blank from room temperature to 200-350°C at a heating rate of 5-40°C / h, and keeping it at 200-350°C for 80-140min, then heating it to 550-650°C at a heating rate of 10-80°C / h, and keeping it at 550-650°C for 300-600min; then, cooling it to 250-350°C at a cooling rate of 40-100°C / h, and finally cooling it to room temperature with the furnace to obtain the light-cured ceramic core blank after degreasing treatment.

[0026] Preferably, the sintering step comprises: heating the degreased light-cured ceramic core blank from room temperature to 950-1100°C at a heating rate of 10-60°C / h, and keeping it at 950-1100°C for 60-120min, then heating it to 1200-1350°C at a heating rate of 30-90°C / h, and keeping it at 1200-1350°C for 600-900min; then cooling it to 800-900°C at a cooling rate of 60-120°C / h, and then cooling it to 450-600°C at a cooling rate of 30-40°C / h, and finally cooling it to room temperature with the furnace to obtain a light-cured 3D printed high-precision ceramic core.

[0027] On the other hand, an embodiment of the present invention provides a photocurable 3D printed high-precision ceramic core, wherein the photocurable 3D printed ceramic core is prepared by the preparation method of the photocurable 3D printed high-precision ceramic core described in any one of the above items.

[0028] Preferably, the microstructure of the photocurable 3D printed high-precision ceramic core contains needle-shaped mullite grains; the mullite grains are intertwined with each other to form mullite aggregates during the growth in all directions; wherein the internal pores of the ceramic core are separated and filled by the aggregates to enhance the matrix continuity of the ceramic core and effectively inhibit the formation and extension of cracks.

[0029] Compared with the prior art, the light-curing 3D printing high-precision ceramic core and the preparation method thereof of the present invention have at least the following beneficial effects:

[0030] The embodiment of the present invention provides a method for preparing a high-precision ceramic core for photocuring 3D printing, by introducing a set content of shrinkage compensating agent (one or more of kyanite, sillimanite, andalusite) into a ceramic mixed powder to coordinately regulate the sintering shrinkage of the ceramic core and the bending strength of the ceramic core. Specifically, the shrinkage compensating agent (kyanite, sillimanite, andalusite) undergoes a phase change decomposition reaction during high-temperature sintering, and the reaction products are mullite and silicon dioxide. This decomposition process is accompanied by a volume expansion of 3-18%, which can compensate for the volume shrinkage caused by structural densification during the sintering process of the ceramic core, thereby achieving the purpose of reducing the sintering shrinkage of the ceramic core and improving the dimensional accuracy. At the same time, the mullite generated by the decomposition of the shrinkage compensating agent under high temperature conditions has a low thermal expansion coefficient and excellent high temperature performance, which plays an important role in regulating the mechanical properties and dimensional accuracy of ceramic materials. The columnar mullite grains generated by the decomposition of the shrinkage compensating agent below 1350°C are interwoven with each other in a mesh structure in the ceramic core, which helps to strengthen the matrix and improve the bending strength of the ceramic core.

[0031] In addition, it should be noted that due to the different volume expansion rates of the shrinkage compensating agent when it decomposes, the regulating effect on the sintering shrinkage of the ceramic core is different. Among them, the volume expansion rate produced by the decomposition of kyanite is the largest, followed by sillimanite, and andalusite is the smallest. Therefore, the regulating effect of the shrinkage compensating agent is kyanite, sillimanite, and andalusite from strong to weak.

[0032] Furthermore, an embodiment of the present invention provides a method for preparing a high-precision ceramic core for photocuring 3D printing, which is designed to have the following sintering treatment steps: heating the degreased photocuring ceramic core blank from room temperature to 950-1100°C at a heating rate of 10-60°C / h, and keeping it at 950-1100°C for 60-120min to allow the ceramic core to be preliminarily sintered at a lower temperature to prevent cracking; then, heating it to 1200-1350°C at a heating rate of 30-90°C / h, and keeping it at 1200-1350°C for 600-900min to ensure that the shrinkage compensator reacts fully; then, cooling it to 800-900°C at a cooling rate of 60-120°C / h, and then cooling it to 450-600°C at a cooling rate of 30-40°C / h, and finally cooling it to room temperature with the furnace. Here, the present invention realizes the coordinated regulation of the shrinkage compensator content and the sintering process based on the decomposition mechanism of the shrinkage compensator and the sintering densification law of the ceramic core. The shrinkage compensator starts to decompose in large quantities between 1200-1350°C, and the heating rate, sintering temperature and holding time are regulated to determine the optimal sintering process, ensure that the shrinkage compensator is fully decomposed during the sintering process, and coordinately regulate the sintering shrinkage and bending strength of the ceramic core.

[0033] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of the effect of different kyanite contents (the content of shrinkage compensating agent in the ceramic mixed powder) on the shrinkage rate of the ceramic core when the sintering temperature is 1250°C;

[0035] Figure 2 It is a schematic diagram showing the effect of different sintering temperatures on the bending strength when the content of kyanite in the ceramic mixed powder is 6wt%;

[0036] Figure 3 This is a physical picture of a ceramic core prepared when the content of kyanite in the ceramic mixed powder is 8wt% and the maximum sintering temperature is 1250°C;

[0037] Figure 4 This is a microstructure diagram of the ceramic core prepared in Example 1. DETAILED DESCRIPTION

[0038] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation methods, structures, features and effects of the present invention application are described in detail below in conjunction with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures, or characteristics in one or more embodiments may be combined in any suitable form.

[0039] The embodiment of the present invention provides a photocuring 3D printing high-precision ceramic core and a preparation method thereof, which mainly includes the following steps:

[0040] Preparation of photocurable ceramic slurry: wherein, this step comprises the following steps: 1) weighing skeleton powder, filler and shrinkage compensator and mixing and stirring to obtain ceramic mixed powder; measuring photocurable resin and dispersant, mixing to obtain photocurable resin premix; 2) adding the above-obtained ceramic mixed powder to the photocurable resin premix, mechanically stirring to obtain ceramic slurry; weighing photoinitiator and adding it to the ceramic slurry, and continuing to stir to obtain photocurable ceramic slurry; 3) transferring the photocurable ceramic slurry to a high-speed planetary ball mill for ball milling, and the ball milling time is 2-3h; the ball-milled photocurable ceramic slurry is subjected to vacuum degassing treatment in a vacuum degassing machine, preferably, the vacuum degassing time is 3-5min.

[0041] The shrinkage compensating agent is selected from one or more of kyanite, sillimanite and andalusite. The shrinkage compensating agent is a powder with a particle size of 5-35 μm.

[0042] Preferably, the ceramic mixed powder includes, by mass fraction, 60-90wt% skeleton powder, 5-25wt% filler, and 5-15wt% shrinkage compensator. Preferably, the skeleton powder is selected from one or two of Al2O3 and SiO2. The particle size of the skeleton powder is 4-70μm; the filler is selected from one or two of ZrO2 and ZrSiO4; the particle size of the filler is 0.1-1μm.

[0043] Preferably, the photocurable resin is two or more of 1,6-hexanediol diacrylate, ethoxylated bisphenol A diacrylate, 1,1,1 trimethylolpropane triacrylate, ethoxylated pentaerythritol tetraacrylate, propoxylated glycerol triacrylate, and trimethylolpropane triacrylate. Preferably, the dispersant of the present invention is one or two of BYK111, BYK180, BYK9076, BYKw969, BYK151, and BYK2000.

[0044] Preferably, the photoinitiator of the present invention is one or two of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, benzoin diethyl ether and (2,4,6-trimethylbenzoyl)-diphenylphosphine oxide. Preferably, the mass of the photoinitiator is 0.01-0.4% of the mass of the ceramic slurry.

[0045] Preferably, in step 3), the mass ratio of grinding balls to slurry is (2-6): (1-5), and the speed of the ball mill is 250-600 r / min.

[0046] Photocuring 3D printing: The photocuring ceramic slurry is subjected to photocuring 3D printing to obtain a photocuring ceramic core blank. The process parameters of the photocuring 3D printing are controlled as follows: the curing thickness is 100-220 μm, and the curing power is 2-10 mW / cm 2 , the single layer curing time is 4-7s.

[0047] Degreasing and sintering treatment: The photocuring ceramic core blank is subjected to degreasing treatment and sintering treatment in sequence to obtain a photocuring 3D printing high-precision ceramic core.

[0048] The degreasing step comprises: heating the light-cured ceramic core blank from room temperature to 200-350°C at a heating rate of 5-40°C / h, and keeping the temperature at 200-350°C for 80-140min to volatilize the resin organic matter, then heating the temperature to 550-650°C at a heating rate of 10-80°C / h, and keeping the temperature at 550-650°C for 300-600min to ensure the complete removal of the resin organic matter; then, cooling the temperature to 250-350°C at a cooling rate of 40-100°C / h, and finally cooling the temperature to room temperature with the furnace to obtain the light-cured ceramic core blank after degreasing treatment.

[0049] The sintering step comprises: heating the degreased light-cured ceramic core blank from room temperature to 950-1100° C. at a heating rate of 10-60° C. / h, and keeping the temperature at 950-1100° C. for 60-120 min to preliminarily sinter the ceramic core at a relatively low temperature to prevent cracking; then, heating the blank to 1200-1350° C. at a heating rate of 30-90° C. / h, and keeping the temperature at 1200-1350° C. for 600-900 min to ensure that the shrinkage compensating agent fully reacts; then, cooling the blank to 800-900° C. at a cooling rate of 60-120° C. / h, and then cooling the blank to 450-600° C. at a cooling rate of 30-40° C. / h, and finally cooling the blank to room temperature with the furnace to obtain a light-cured 3D printed high-precision ceramic core.

[0050] The technical solution of the present invention will be further described in detail below in conjunction with specific embodiments. The described embodiments are only part of the embodiments of the present invention, not all of the embodiments, and the protection scope of the present invention is not limited to the described contents.

[0051] Example 1

[0052] This embodiment prepares a high-precision ceramic core for photocuring 3D printing, which mainly includes the following steps:

[0053] Preparation of photocurable ceramic slurry: 1) weighing SiO2 powder with a particle size of 10 μm, ZrSiO4 powder with a particle size of 1 μm and kyanite powder with a particle size of 8 μm and mixing them evenly to obtain a ceramic mixed powder; weighing HDDA resin, TMPTA resin and dispersant BYK111 and mixing them to obtain a photocurable resin premix; 2) adding the ceramic mixed powder to the photocurable resin premix, mechanically stirring to obtain a ceramic slurry, weighing the mass of the ceramic slurry and adding a photoinitiator phenyl bis (2,4,6-trimethylbenzoyl) phosphine oxide at 0.1% of the mass of the ceramic slurry, and continuing to stir to obtain a photocurable ceramic slurry with a solid content of 60 vol%; (3) transferring the photocurable ceramic slurry obtained in step 2) to a high-speed planetary ball mill for ball milling, wherein the mass ratio of grinding balls to slurry is 2:3, the ball mill speed is 400 r / min, and the ball milling time is 2 h; then, the ball-milled photocurable ceramic slurry is vacuum defoamed for 5 min.

[0054] The ceramic mixed powder includes 77wt% of skeleton powder (SiO2 powder), 15wt% of filler (ZrSiO4 powder), and 8wt% of shrinkage compensator (kyanite powder) by mass fraction. In the photocurable resin prepolymer, the volume ratio of 1,6-hexanediol diacrylate HDDA: trimethylolpropane triacrylate TMPTA: dispersant BYK111 is 6:2:1.

[0055] Photocuring 3D printing: The photocuring ceramic slurry is subjected to photocuring 3D printing to obtain a photocuring ceramic core blank.

[0056] The light-curing 3D printing parameters were set as follows: curing thickness was 150 μm, curing power was 5 mW / cm 2 , the single layer curing time is 5s.

[0057] Degreasing and sintering treatment: The photocuring ceramic core blank is subjected to degreasing treatment and sintering treatment in sequence to obtain a photocuring 3D printing high-precision ceramic core.

[0058] Among them, the degreasing process is: heating the light-cured ceramic core blank from room temperature to 300°C at a heating rate of 10°C / h, and keeping it at 300°C for 120 minutes, then heating it to 600°C at a heating rate of 40°C / h, and keeping it at 600°C for 360 minutes; then, cooling it to 300°C at a cooling rate of 60°C / h, and finally cooling it to room temperature with the furnace to obtain the light-cured ceramic core blank after degreasing treatment.

[0059] Among them, the sintering process is as follows: the degreased light-cured ceramic core blank is heated from room temperature to 1000°C at a heating rate of 60°C / h, and kept at 1000°C for 60 minutes, then heated to 1250°C at a heating rate of 30°C / h, and kept at 1250°C for 600 minutes; then, cooled to 800°C at a cooling rate of 80°C / h, and then cooled to 500°C at a cooling rate of 40°C / h, and finally cooled to room temperature with the furnace to obtain a light-cured 3D printed high-precision ceramic core.

[0060] Example 2

[0061] This embodiment prepares a high-precision ceramic core for photocuring 3D printing, which mainly includes the following steps:

[0062] Preparation of photocurable ceramic slurry: 1) weighing SiO2 powder with a particle size of 10 μm, ZrSiO4 powder with a particle size of 1 μm and kyanite powder with a particle size of 8 μm and mixing them evenly to obtain a ceramic mixed powder; weighing HDDA resin, TMPTA resin and dispersant BYK9076 and mixing them to obtain a photocurable resin premix; 2) adding the ceramic mixed powder to the photocurable resin premix, mechanically stirring to obtain a ceramic slurry, weighing the ceramic slurry mass and calculating 0.001% of the ceramic slurry mass; .1% photoinitiator phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide is added, and stirring is continued to obtain a photocurable ceramic slurry with a solid content of 60 vol%; (3) the photocurable ceramic slurry obtained in step 2) is transferred to a high-speed planetary ball mill for ball milling, wherein the mass ratio of grinding balls to slurry is 2:3, the ball mill speed is 400 r / min, and the ball milling time is 2 h; then, the ball-milled photocurable ceramic slurry is vacuum defoamed for 5 min.

[0063] The ceramic mixed powder includes 79wt% of skeleton powder (SiO2 powder), 15wt% of filler (ZrSiO4 powder), and 6wt% of shrinkage compensator (kyanite powder) by mass fraction. In the photocurable resin prepolymer, the volume ratio of 1,6-hexanediol diacrylate HDDA: trimethylolpropane triacrylate TMPTA: dispersant BYK9076 is 6:2:1.

[0064] Photocuring 3D printing: The photocuring ceramic slurry is subjected to photocuring 3D printing to obtain a photocuring ceramic core blank.

[0065] The light-curing 3D printing parameters were set as follows: curing thickness was 170 μm, curing power was 6 mW / cm 2 , the single layer curing time is 5s.

[0066] Degreasing and sintering treatment: The photocuring ceramic core blank is subjected to degreasing treatment and sintering treatment in sequence to obtain a photocuring 3D printed ceramic core.

[0067] Among them, the degreasing process is: heating the light-cured ceramic core blank from room temperature to 300°C at a heating rate of 10°C / h, and keeping it at 300°C for 120 minutes, then heating it to 600°C at a heating rate of 40°C / h, and keeping it at 600°C for 360 minutes; then, cooling it to 300°C at a cooling rate of 60°C / h, and finally cooling it to room temperature with the furnace to obtain the light-cured ceramic core blank after degreasing treatment.

[0068] Among them, the sintering process is as follows: the degreased light-cured ceramic core blank is heated from room temperature to 1000°C at a heating rate of 60°C / h, and kept at 1000°C for 60 minutes, then heated to 1300°C at a heating rate of 30°C / h, and kept at 1300°C for 600 minutes; then, it is cooled to 800°C at a cooling rate of 80°C / h, and then cooled to 500°C at a cooling rate of 40°C / h, and finally cooled to room temperature with the furnace to obtain a light-cured 3D printed high-precision ceramic core.

[0069] Example 3

[0070] This embodiment prepares a high-precision ceramic core for photocuring 3D printing, which mainly includes the following steps:

[0071] Preparation of photocurable ceramic slurry: 1) weighing SiO2 powder with a particle size of 10 μm, ZrSiO4 powder with a particle size of 1 μm and sillimanite powder with a particle size of 32 μm and mixing them evenly to obtain a ceramic mixed powder; weighing HDDA resin, TMPTA resin and dispersant BYK151 and mixing them to obtain a photocurable resin premix; 2) adding the ceramic mixed powder to the photocurable resin premix, mechanically stirring to obtain a ceramic slurry, weighing the ceramic slurry mass and adjusting the mass by 0. 1% photoinitiator (2,4,6-trimethylbenzoyl)-diphenylphosphine oxide was added, and stirring was continued to obtain a photocurable ceramic slurry with a solid content of 60 vol%; (3) the photocurable ceramic slurry obtained in step 2) was transferred to a high-speed planetary ball mill for ball milling, wherein the mass ratio of grinding balls to slurry was 2:3, the ball mill speed was 400 r / min, and the ball milling time was 2 h; then, the ball-milled photocurable ceramic slurry was vacuum defoamed for 5 min.

[0072] The ceramic mixed powder includes 84wt% of skeleton powder (SiO2 powder), 10wt% of filler (ZrSiO4 powder), and 6wt% of shrinkage compensator (sillimanite powder) by mass fraction. In the photocurable resin prepolymer, the volume ratio of 1,6-hexanediol diacrylate HDDA: trimethylolpropane triacrylate TMPTA: dispersant BYK151 is 6:2:1.

[0073] Photocuring 3D printing: The photocuring ceramic slurry is subjected to photocuring 3D printing to obtain a photocuring ceramic core blank.

[0074] The light-curing 3D printing parameters were set as follows: curing thickness was 180 μm, curing power was 7 mW / cm 2 , the single layer curing time is 5s.

[0075] Degreasing and sintering treatment: The photocuring ceramic core blank is subjected to degreasing treatment and sintering treatment in sequence to obtain a photocuring 3D printed ceramic core.

[0076] Among them, the degreasing process is: heating the light-cured ceramic core blank from room temperature to 300°C at a heating rate of 10°C / h, and keeping it at 300°C for 120 minutes, then heating it to 600°C at a heating rate of 40°C / h, and keeping it at 600°C for 360 minutes; then, cooling it to 300°C at a cooling rate of 60°C / h, and finally cooling it to room temperature with the furnace to obtain the light-cured ceramic core blank after degreasing treatment.

[0077] Among them, the sintering process is as follows: the degreased light-cured ceramic core blank is heated from room temperature to 1000°C at a heating rate of 60°C / h, and kept at 1000°C for 60 minutes, then heated to 1250°C at a heating rate of 30°C / h, and kept at 1250°C for 600 minutes; then, cooled to 800°C at a cooling rate of 80°C / h, and then cooled to 500°C at a cooling rate of 40°C / h, and finally cooled to room temperature with the furnace to obtain a light-cured 3D printed high-precision ceramic core.

[0078] Example 4

[0079] This embodiment prepares a high-precision ceramic core for photocuring 3D printing, which mainly includes the following steps:

[0080] Preparation of photocurable ceramic slurry: 1) weighing SiO2 powder with a particle size of 10 μm, ZrSiO4 powder with a particle size of 1 μm and andalusite powder with a particle size of 28 μm and mixing them evenly to obtain a ceramic mixed powder; weighing HDDA resin, TMPTA resin and dispersant BYK9076 and mixing them to obtain a photocurable resin premix; 2) adding the ceramic mixed powder to the photocurable resin premix, mechanically stirring to obtain a ceramic slurry, weighing the ceramic slurry mass and calculating 0.001% of the ceramic slurry mass; .1% photoinitiator (2,4,6-trimethylbenzoyl)-diphenylphosphine oxide is added, and stirring is continued to obtain a photocurable ceramic slurry with a solid content of 60 vol%; (3) the photocurable ceramic slurry obtained in step 2) is transferred to a high-speed planetary ball mill for ball milling, wherein the mass ratio of grinding balls to slurry is 2:3, the ball mill speed is 400 r / min, and the ball milling time is 2 h; then, the ball-milled photocurable ceramic slurry is vacuum defoamed for 5 min.

[0081] The ceramic mixed powder includes 84wt% of skeleton powder (SiO2 powder), 10wt% of filler (ZrSiO4 powder), and 6wt% of shrinkage compensator (andalusite powder) by mass fraction. In the photocurable resin prepolymer, the volume ratio of 1,6-hexanediol diacrylate HDDA: trimethylolpropane triacrylate TMPTA: dispersant BYK9076 is 6:2:1.

[0082] Photocuring 3D printing: The photocuring ceramic slurry is subjected to photocuring 3D printing to obtain a photocuring ceramic core blank.

[0083] The light-curing 3D printing parameters were set as follows: curing thickness was 160 μm, curing power was 7 mW / cm 2 , the single layer curing time is 5s.

[0084] Degreasing and sintering treatment: The photocuring ceramic core blank is subjected to degreasing treatment and sintering treatment in sequence to obtain a photocuring 3D printed ceramic core.

[0085] Among them, the degreasing process is: heating the light-cured ceramic core blank from room temperature to 300°C at a heating rate of 10°C / h, and keeping it at 300°C for 120 minutes, then heating it to 600°C at a heating rate of 40°C / h, and keeping it at 600°C for 360 minutes; then, cooling it to 300°C at a cooling rate of 60°C / h, and finally cooling it to room temperature with the furnace to obtain the light-cured ceramic core blank after degreasing treatment.

[0086] Among them, the sintering process is as follows: the degreased light-cured ceramic core blank is heated from room temperature to 1000°C at a heating rate of 60°C / h, and kept at 1000°C for 60 minutes, then heated to 1250°C at a heating rate of 30°C / h, and kept at 1250°C for 600 minutes; then, cooled to 800°C at a cooling rate of 80°C / h, and then cooled to 500°C at a cooling rate of 40°C / h, and finally cooled to room temperature with the furnace to obtain a light-cured 3D printed high-precision ceramic core.

[0087] Comparative Example 1

[0088] Comparative Example 1: A photocurable 3D printed ceramic core is prepared, which mainly includes the following steps:

[0089] Preparation of photocurable ceramic slurry: 1) weighing SiO2 powder with a particle size of 10 μm, ZrSiO4 powder with a particle size of 1 μm and kyanite powder with a particle size of 8 μm and mixing them evenly to obtain a ceramic mixed powder; weighing HDDA resin, TMPTA resin and dispersant BYK111 and mixing them to obtain a photocurable resin premix; 2) adding the ceramic mixed powder to the photocurable resin premix, mechanically stirring to obtain a ceramic slurry, weighing the mass of the ceramic slurry and adding a photoinitiator phenyl bis (2,4,6-trimethylbenzoyl) phosphine oxide at 0.1% of the mass of the ceramic slurry, and continuing to stir to obtain a photocurable ceramic slurry with a solid content of 60 vol%; (3) transferring the photocurable ceramic slurry obtained in step 2) to a high-speed planetary ball mill for ball milling, wherein the mass ratio of grinding balls to slurry is 2:3, the ball mill speed is 400 r / min, and the ball milling time is 2 h; then, the ball-milled photocurable ceramic slurry is vacuum defoamed for 5 min.

[0090] The ceramic mixed powder includes 83wt% of skeleton powder (SiO2 powder), 15wt% of filler (ZrSiO4 powder), and 2wt% of shrinkage compensator (kyanite powder) by mass fraction. In the photocurable resin prepolymer, the volume ratio of 1,6-hexanediol diacrylate HDDA: trimethylolpropane triacrylate TMPTA: dispersant BYK111 is 6:2:1.

[0091] Photocuring 3D printing: The photocuring ceramic slurry is subjected to photocuring 3D printing to obtain a photocuring ceramic core blank.

[0092] The light-curing 3D printing parameters were set as follows: curing thickness was 180 μm, curing power was 6 mW / cm 2 , the single layer curing time is 5s.

[0093] Degreasing and sintering treatment: The photocuring ceramic core blank is subjected to degreasing treatment and sintering treatment in sequence to obtain a photocuring 3D printed ceramic core.

[0094] Among them, the degreasing process is: heating the light-cured ceramic core blank from room temperature to 300°C at a heating rate of 10°C / h, and keeping it at 300°C for 120 minutes, then heating it to 600°C at a heating rate of 40°C / h, and keeping it at 600°C for 360 minutes; then, cooling it to 300°C at a cooling rate of 60°C / h, and finally cooling it to room temperature with the furnace to obtain the light-cured ceramic core blank after degreasing treatment.

[0095] Among them, the sintering process is as follows: the degreased light-cured ceramic core blank is heated from room temperature to 1000°C at a heating rate of 60°C / h, and kept at 1000°C for 60 minutes, then heated to 1250°C at a heating rate of 30°C / h, and kept at 1250°C for 600 minutes; then, cooled to 800°C at a cooling rate of 80°C / h, and then cooled to 500°C at a cooling rate of 40°C / h, and finally cooled to room temperature with the furnace to obtain a light-cured 3D printed ceramic core.

[0096] Comparative Example 2

[0097] Comparative Example 2: A photocurable 3D printed ceramic core is prepared, which mainly includes the following steps:

[0098] Preparation of photocurable ceramic slurry: 1) weighing SiO2 powder with a particle size of 10 μm, ZrSiO4 powder with a particle size of 1 μm and kyanite powder with a particle size of 8 μm and mixing them evenly to obtain a ceramic mixed powder; weighing HDDA resin, TMPTA resin and dispersant BYK9076 and mixing them to obtain a photocurable resin premix; 2) adding the ceramic mixed powder to the photocurable resin premix, mechanically stirring to obtain a ceramic slurry, weighing the ceramic slurry mass and adjusting the mass by 0. 1% of photoinitiator phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide was added, and stirring was continued to obtain a photocurable ceramic slurry with a solid content of 60 vol.%; (3) the photocurable ceramic slurry obtained in step 2) was transferred to a high-speed planetary ball mill for ball milling, wherein the mass ratio of grinding balls to slurry was 2:3, the ball mill speed was 400 r / min, and the ball milling time was 2 h; then, the ball-milled photocurable ceramic slurry was vacuum defoamed for 5 min.

[0099] The ceramic mixed powder includes 83wt% of skeleton powder (SiO2 powder), 15wt% of filler (ZrSiO4 powder), and 2wt% of shrinkage compensator (kyanite powder) by mass fraction. In the photocurable resin prepolymer, the volume ratio of 1,6-hexanediol diacrylate HDDA: trimethylolpropane triacrylate TMPTA: dispersant BYK111 is 6:2:1.

[0100] Photocuring 3D printing: The photocuring ceramic slurry is subjected to photocuring 3D printing to obtain a photocuring ceramic core blank.

[0101] The light-curing 3D printing parameters were set as follows: curing thickness was 170 μm, curing power was 6 mW / cm 2 , the single layer curing time is 5s.

[0102] Degreasing and sintering treatment: The photocuring ceramic core blank is subjected to degreasing treatment and sintering treatment in sequence to obtain a photocuring 3D printed ceramic core.

[0103] Among them, the degreasing process is: heating the light-cured ceramic core blank from room temperature to 300°C at a heating rate of 10°C / h, and keeping it at 300°C for 120 minutes, then heating it to 600°C at a heating rate of 40°C / h, and keeping it at 600°C for 360 minutes; then, cooling it to 300°C at a cooling rate of 60°C / h, and finally cooling it to room temperature with the furnace to obtain the light-cured ceramic core blank after degreasing treatment.

[0104] Among them, the sintering process is as follows: the degreased light-cured ceramic core blank is heated from room temperature to 1000°C at a heating rate of 60°C / h, and kept at 1000°C for 60 minutes, then heated to 1300°C at a heating rate of 30°C / h, and kept at 1300°C for 600 minutes; then, it is cooled to 800°C at a cooling rate of 80°C / h, and then cooled to 500°C at a cooling rate of 40°C / h, and finally cooled to room temperature with the furnace to obtain a light-cured 3D printed ceramic core.

[0105] Comparative Example 3

[0106] Comparative Example 3: A photocurable 3D printed ceramic core is prepared, which mainly includes the following steps:

[0107] Preparation of photocurable ceramic slurry: 1) weighing SiO2 powder with a particle size of 10 μm, ZrSiO4 powder with a particle size of 1 μm and kyanite powder with a particle size of 8 μm and mixing them evenly to obtain a ceramic mixed powder; weighing HDDA resin, TMPTA resin and dispersant BYK9076 and mixing them to obtain a photocurable resin premix; 2) adding the ceramic mixed powder to the photocurable resin premix, mechanically stirring to obtain a ceramic slurry, weighing the ceramic slurry mass and adjusting the mass by 0. 1% of photoinitiator phenyl bis(2,4,6-trimethylbenzoyl)phosphine oxide was added, and stirring was continued to obtain a photocurable ceramic slurry with a solid content of 60 vol.%; (3) the photocurable ceramic slurry obtained in step 2) was transferred to a high-speed planetary ball mill for ball milling, wherein the mass ratio of grinding balls to slurry was 2:3, the ball mill speed was 400 r / min, and the ball milling time was 2 h; then, the ball-milled photocurable ceramic slurry was vacuum defoamed for 5 min.

[0108] The ceramic mixed powder includes 77wt% of skeleton powder (SiO2 powder), 15wt% of filler (ZrSiO4 powder), and 8wt% of shrinkage compensator (kyanite powder) by mass fraction. In the photocurable resin prepolymer, the volume ratio of 1,6-hexanediol diacrylate HDDA: trimethylolpropane triacrylate TMPTA: dispersant BYK9076 is 6:2:1.

[0109] Photocuring 3D printing: The photocuring ceramic slurry is subjected to photocuring 3D printing to obtain a photocuring ceramic core blank.

[0110] The light-curing 3D printing parameters were set as follows: curing thickness was 150 μm, curing power was 5 mW / cm 2 , the single layer curing time is 5s.

[0111] Degreasing and sintering treatment: The photocuring ceramic core blank is subjected to degreasing treatment and sintering treatment in sequence to obtain a photocuring 3D printed ceramic core.

[0112] Among them, the degreasing process is: heating the light-cured ceramic core blank from room temperature to 300°C at a heating rate of 10°C / h, and keeping it at 300°C for 120 minutes, then heating it to 600°C at a heating rate of 40°C / h, and keeping it at 600°C for 360 minutes; then, cooling it to 300°C at a cooling rate of 60°C / h, and finally cooling it to room temperature with the furnace to obtain the light-cured ceramic core blank after degreasing treatment.

[0113] Among them, the sintering process is as follows: the degreased light-cured ceramic core blank is heated from room temperature to 1000°C at a heating rate of 60°C / h, and kept at 1000°C for 60 minutes, then heated to 1150°C at a heating rate of 30°C / h, and kept at 1150°C for 600 minutes; then, cooled to 800°C at a cooling rate of 80°C / h, and then cooled to 500°C at a cooling rate of 40°C / h, and finally cooled to room temperature with the furnace to obtain a light-cured 3D printed ceramic core.

[0114] Comparative Example 4

[0115] Comparative Example 4: A photocurable 3D printed ceramic core is prepared, which mainly includes the following steps:

[0116] Preparation of photocurable ceramic slurry: 1) weighing SiO2 powder with a particle size of 10 μm and ZrSiO4 powder with a particle size of 1 μm and mixing them evenly to obtain a ceramic mixed powder; weighing HDDA resin, TMPTA resin and dispersant BYK111 and mixing them to obtain a photocurable resin premix; 2) adding the ceramic mixed powder to the photocurable resin premix, mechanically stirring to obtain a ceramic slurry with a solid content of 60 vol.%, weighing the mass of the ceramic slurry and adding a photoinitiator phenyl bis (2,4,6-trimethylbenzoyl) phosphine oxide at 0.1% of the mass of the ceramic slurry, and continuing to stir to obtain a photocurable ceramic slurry; (3) transferring the photocurable ceramic slurry obtained in step 2) to a high-speed planetary ball mill for ball milling, wherein the mass ratio of grinding balls to slurry is 2:3, the ball mill speed is 400 r / min, and the ball milling time is 2 h; then, the ball-milled photocurable ceramic slurry is vacuum defoamed for 5 min.

[0117] The ceramic mixed powder includes 85wt% of skeleton powder (SiO2 powder) and 15wt% of filler (ZrSiO4 powder) by mass fraction. In the photocurable resin prepolymer, the volume ratio of 1,6-hexanediol diacrylate HDDA: trimethylolpropane triacrylate TMPTA: dispersant BYK111 is 6:2:1.

[0118] Photocuring 3D printing: The photocuring ceramic slurry is subjected to photocuring 3D printing to obtain a photocuring ceramic core blank.

[0119] The light-curing 3D printing parameters were set as follows: curing thickness was 180 μm, curing power was 5 mW / cm 2 , the single layer curing time is 5s.

[0120] Degreasing and sintering treatment: The photocuring ceramic core blank is subjected to degreasing treatment and sintering treatment in sequence to obtain a photocuring 3D printed ceramic core.

[0121] Among them, the degreasing process is: heating the light-cured ceramic core blank from room temperature to 300°C at a heating rate of 10°C / h, and keeping it at 300°C for 120 minutes, then heating it to 600°C at a heating rate of 40°C / h, and keeping it at 600°C for 360 minutes; then, cooling it to 300°C at a cooling rate of 60°C / h, and finally cooling it to room temperature with the furnace to obtain the light-cured ceramic core blank after degreasing treatment.

[0122] Among them, the sintering process is as follows: the degreased light-cured ceramic core blank is heated from room temperature to 1000°C at a heating rate of 60°C / h, and kept at 1000°C for 60 minutes, then heated to 1250°C at a heating rate of 30°C / h, and kept at 1250°C for 600 minutes; then, cooled to 800°C at a cooling rate of 80°C / h, and then cooled to 500°C at a cooling rate of 40°C / h, and finally cooled to room temperature with the furnace to obtain a light-cured 3D printed ceramic core.

[0123] The light-cured 3D printed ceramic cores prepared in the above examples and comparative examples were tested, and the test results are shown in Table 1:

[0124] Table 1

[0125]

[0126] in addition, Figure 1 The figure shows the effect of different kyanite contents in the ceramic mixed powder on the shrinkage of the ceramic core when the maximum sintering temperature is 1250°C. It can be seen that with the increase of kyanite content, the shrinkage of the ceramic core in the three directions of X, Y, and Z gradually decreases. The volume expansion caused by the decomposition of kyanite at high temperature offsets part of the sintering shrinkage, the shrinkage rate is reduced, and the dimensional accuracy of the ceramic core is improved. When the kyanite content is 8wt%, the volume expansion accompanied by the pyrolysis reaction keeps the shrinkage of the ceramic core at a relatively small level.

[0127] Figure 2The effect of different sintering temperatures on the flexural strength when the kyanite content in the ceramic mixed powder is 6wt% is shown. Kyanite decomposes under high temperature conditions, and the pyrolysis product mullite has a regulating effect on the mechanical properties of the ceramic core. As the sintering temperature increases, kyanite is fully decomposed, the generated mullite phase increases, and the bonding between the ceramic particles is enhanced, and the ceramic matrix is ​​strengthened. Therefore, the room temperature flexural strength and high temperature flexural strength of the ceramic core gradually increase.

[0128] Figure 3 Shown is a physical picture of a ceramic core prepared when the kyanite content in the ceramic mixed powder is 8wt% and the maximum sintering temperature is 1250°C (i.e., a physical picture of a light-cured 3D-printed high-precision ceramic core prepared in Example 1).

[0129] Figure 4 The microstructure of the ceramic core prepared in Example 1 is shown. It can be seen that the needle-shaped mullite network aggregates generated by the decomposition of kyanite, here because the mullite crystal plane interface energy parallel to the c-axis direction is low, the mullite finally exists in a needle-shaped morphology. The mullite grains interweave with each other to form mullite aggregates during the growth process in all directions. The pores inside the ceramic core are separated and filled by the aggregates, the continuity of the matrix is ​​enhanced, the formation and extension of cracks can be effectively suppressed, and the mechanical properties of the core are improved.

[0130] From Table 1 and the accompanying drawings, we can see that:

[0131] 1) The performance of the light-cured ceramic core prepared in the embodiment of the present invention is significantly better than that in the comparative example.

[0132] 2) It can be seen from Comparative Example 1 that when the amount of kyanite added is small, the volume expansion effect associated with the decomposition reaction is weak, the compensation effect on sintering shrinkage is not obvious, the sintering shrinkage is large, and the dimensional accuracy is lower than that of the embodiment.

[0133] It can be seen from Example 2 and Comparative Example 2 that: at the same sintering temperature of 1300° C., the larger kyanite content in the ceramic core of Example 2 leads to an increase in the amount of mullite generated during the sintering process, strengthening the ceramic matrix and improving the mechanical properties.

[0134] Compared with Example 3, the content of kyanite in the ceramic core is higher, but the sintering temperature does not reach the temperature at which kyanite decomposes in large quantities, the volume expansion effect is weak, and the lower sintering temperature cannot fully sinter the ceramic core. Therefore, the dimensional accuracy is low and the mechanical properties are poor.

[0135] Comparative Example 4 shows the performance of a ceramic core without shrinkage compensating agent. Due to high temperature sintering, the shrinkage rate of the core is large and the dimensional accuracy is poor. However, shrinkage compensating agents such as kyanite, sillimanite and andalusite are added to the examples, so that the shrinkage rate of the ceramic core is effectively controlled. The regulation effects of the shrinkage compensating agents are kyanite, sillimanite and andalusite in order.

[0136] 3) Combination Figure 1 It can be seen from Table 1 that kyanite has a significant improvement effect on the dimensional accuracy of the ceramic core. The pyrolysis of kyanite at high temperature is accompanied by a volume expansion of 16-18%, and the decomposition products are mullite and silicon dioxide. The resulting volume effect can offset part of the volume shrinkage of the ceramic core during the sintering process, reduce the shrinkage rate, and improve the dimensional accuracy.

[0137] 4) Mullite, a pyrolysis product of kyanite, has a certain regulatory effect on the mechanical properties of the ceramic core. The decomposition of kyanite causes a large number of pores and cracks to appear inside the core, and the bending strength decreases. Among them, when the sintering temperature reaches 1300℃, kyanite decomposes in large quantities, and the pyrolysis product mullite strengthens the ceramic matrix, enhances the continuity between ceramic particles, and improves the mechanical properties of the core.

[0138] 5) The decomposition temperature of kyanite is 1200-1350°C. Increasing the sintering temperature is beneficial to the full sintering of the ceramic core and the decomposition of kyanite, and improves the mechanical properties of the ceramic core, but at the same time increases the shrinkage rate. Compared with Comparative Example 3, when the maximum sintering temperature in Example 2 is 1300°C, the shrinkage rate and flexural strength of the ceramic core increase to varying degrees, but the increase in shrinkage rate is small, and the flexural strength is significantly improved.

[0139] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention still falls within the scope of the technical solution of the present invention.

Claims

1. A method for preparing a high-precision ceramic core by photocuring 3D printing, characterized in that: It includes the following steps: Preparation of photocurable ceramic slurry: preparing a ceramic mixed powder, a photocurable resin, a dispersant and an initiator into a photocurable ceramic slurry; wherein, in terms of mass percentage, the ceramic mixed powder comprises 60-90wt% of a skeleton powder, 5-25wt% of a filler, and 5-15wt% of a shrinkage compensating agent; wherein the shrinkage compensating agent is selected from one or more of kyanite, sillimanite and andalusite; Photocuring 3D printing process: performing photocuring 3D printing process on the photocuring ceramic slurry to obtain a photocuring ceramic core blank; Degreasing and sintering treatment: The photocuring ceramic core blank is subjected to degreasing treatment and sintering treatment in sequence to obtain a photocuring 3D printing high-precision ceramic core.

2. The method for preparing a high-precision ceramic core by photocuring 3D printing according to claim 1, characterized in that: The step of preparing the light-cured ceramic slurry comprises: 1) mixing skeleton powder, filler and shrinkage compensating agent to obtain ceramic mixed powder; Mixing a photocurable resin and a dispersant in a volume ratio of (5-11):(1-3) to obtain a photocurable resin premix; 2) mixing the ceramic mixed powder with the photocurable resin premix to obtain a ceramic slurry with a solid content of 40-65 vol%; then adding an initiator to the ceramic slurry and stirring to obtain a photocurable ceramic slurry; 3) performing ball milling and vacuum degassing treatment on the photocurable ceramic slurry in sequence; Preferably, the vacuum degassing treatment time is 3-5min; Preferably, the ball milling time is 2-3h; Preferably, in the ball milling process, the mass ratio of the grinding balls to the photocurable ceramic slurry is (2-6): (1-5); Preferably, during the ball milling process, the rotation speed of the ball mill is 250-600 r / min.

3. The method for preparing a high-precision ceramic core by photocuring 3D printing according to claim 2, characterized in that: The mass of the photoinitiator is 0.01-0.4% of the mass of the ceramic slurry.

4. The method for preparing a high-precision ceramic core by photocuring 3D printing according to any one of claims 1 to 3, characterized in that: The shrinkage compensating agent is a powder with a particle size of 5-35 μm.

5. The method for preparing a high-precision ceramic core by photocuring 3D printing according to any one of claims 1 to 4, characterized in that: The skeleton powder is selected from one or two of Al2O3 and SiO2; and / or The particle size of the skeleton powder is 4-70 μm; and / or The filler is one or two of ZrO2 and ZrSiO4; and / or The particle size of the filler is 0.1-1 μm.

6. The method for preparing a high-precision ceramic core by photocuring 3D printing according to any one of claims 1 to 5, characterized in that: The photocurable resin is selected from one or more of 1,6-hexanediol diacrylate, ethoxylated bisphenol A diacrylate, 1,1,1 trimethylolpropane triacrylate, ethoxylated pentaerythritol tetraacrylate, propoxylated glycerol triacrylate and trimethylolpropane triacrylate; and / or The dispersant is one or more of BYK111, BYK180, BYK9076, BYKW969, BYK151, BYK2000; and / or The photoinitiator is one or two of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, benzoin diethyl ether and (2,4,6-trimethylbenzoyl)-diphenylphosphine oxide.

7. The method for preparing a high-precision ceramic core by photocuring 3D printing according to any one of claims 1 to 6, characterized in that: In the step of the light-curing 3D printing process, the process parameters of the light-curing 3D printing process are controlled as follows: The curing thickness is 100-220μm and the curing power is 2-10mW / cm 2 , the single layer curing time is 4-7s.

8. The method for preparing a high-precision ceramic core by photocuring 3D printing according to any one of claims 1 to 7, characterized in that: The degreasing step comprises: The photocurable ceramic core blank is heated from room temperature to 200-350°C at a heating rate of 5-40°C / h, and kept at 200-350°C for 80-140min. Thereafter, the temperature is further increased to 550-650°C at a heating rate of 10-80°C / h, and kept at 550-650°C for 300-600min. Then, the temperature is reduced to 250-350°C at a cooling rate of 40-100°C / h, and finally cooled to room temperature with the furnace to obtain a degreased photocurable ceramic core blank.

9. The method for preparing a high-precision ceramic core by photocuring 3D printing according to any one of claims 1 to 8, characterized in that: The sintering step comprises: The degreased light-cured ceramic core blank is heated from room temperature to 950-1100°C at a heating rate of 10-60°C / h, and kept at 950-1100°C for 60-120min, then heated to 1200-1350°C at a heating rate of 30-90°C / h, and kept at 1200-1350°C for 600-900min; then, cooled to 800-900°C at a cooling rate of 60-120°C / h, and then cooled to 450-600°C at a cooling rate of 30-40°C / h, and finally cooled to room temperature with the furnace to obtain a light-cured 3D printed high-precision ceramic core.

10. A high-precision ceramic core for photocuring 3D printing, characterized in that: The photocurable 3D printed ceramic core is prepared by the preparation method of the photocurable 3D printed high-precision ceramic core according to any one of claims 1 to 9; Preferably, the microstructure of the photocurable 3D printed high-precision ceramic core contains needle-shaped mullite grains; the mullite grains are intertwined with each other to form mullite aggregates during the growth in all directions; wherein the internal pores of the ceramic core are separated and filled by the aggregates to enhance the matrix continuity of the ceramic core and effectively inhibit the formation and extension of cracks.

Images