Cerium oxide ceramic slurry suitable for photocuring 3D printing, preparation and forming method

Abstract

The application discloses a kind of ceria ceramic slurry suitable for photocuring 3D printing, preparation and forming method, including surface modified ceria ceramic powder, low absorbance powder filler, slurry liquid phase and photoinitiator, and the surface modified ceria ceramic powder is the ceria ceramic powder with dispersant attached to surface;Wherein: the total mass of ceria ceramic powder and low absorbance powder filler accounts for 40%~50% of the volume of ceria ceramic slurry, the volume ratio of ceria ceramic powder and low absorbance powder filler is (1~4) : 1;The volume of slurry liquid phase accounts for 50%~60% of the volume of ceria ceramic slurry;The mass of dispersant accounts for 1%~3% of the mass of ceria ceramic powder;The mass of photoinitiator accounts for 1%~3% of the mass of slurry liquid phase;According to mass percentage, slurry liquid phase includes 40%~50% 4-acryloyl morpholine as photosensitive monomer, 10%~20% ethoxy pentaerythritol tetraacrylate as crosslinking agent and 30%~40% polypropylene glycol-400 as diluent.The application can realize photocuring 3D printing forming of ceria ceramic sample and preparation of complex porous structure.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of ceria ceramic photocuring 3D printing forming, and particularly relates to a ceria ceramic slurry suitable for photocuring 3D printing, a preparation method and a forming method. BACKGROUND

[0002] As a functional material, ceria (CeO2) ceramic has shown a wide application potential in many high-tech fields due to its unique redox performance, excellent high-temperature stability and chemical inertness. In particular, in the field of complex porous structures, for example, the preparation of three-periodic minimal surface structures as heat exchanger structures, ceria ceramic is an indispensable key material. Although traditional preparation methods such as organic foam impregnation method, foaming method, solid phase sintering method, chemical vapor deposition method and sol-gel method have achieved the preparation of ceria ceramic products to some extent, most of the ceria ceramic products prepared by these methods are limited to disordered foam porous structures, and there are significant defects such as non-uniform pore structure, insufficient mechanical strength, low forming success rate and the like. More importantly, these methods face great challenges in the preparation of ceria ceramic components with precise pore type, porosity and complex geometric characteristics, which seriously restricts the wide application of high-performance ceria ceramic.

[0003] Photocuring 3D printing technology has become a leading technology in additive manufacturing technology due to its high precision, high efficiency and excellent performance in micro complex structures. This technology has been widely used in the forming of resin materials and some low refractive index and low absorbance ceramics (such as alumina and zirconia), and has shown great potential in the field of ceramic material preparation. However, for ceria ceramic, due to its high refractive index and strong absorbance, photocuring 3D printing technology has encountered great obstacles in practical application. Specifically, the ceria ceramic slurry has low solidification thickness during photocuring, which makes it difficult to be effectively formed, which is a key factor restricting the application of photocuring 3D printing technology in the preparation of ceria ceramic components. Therefore, it is urgent to develop a ceria ceramic slurry suitable for photocuring 3D printing and a forming method thereof. SUMMARY

[0004] In view of the problems in the prior art, the application provides a ceria ceramic slurry suitable for photocuring 3D printing, a preparation method and a forming method, which can realize photocuring 3D printing forming of ceria ceramic samples and preparation of complex porous structures.

[0005] In order to solve the above technical problems, the application is implemented by the following technical solutions:

[0006] A cerium oxide ceramic slurry suitable for photopolymerization 3D printing includes surface-modified cerium oxide ceramic powder, low absorbance powder filler, slurry liquid phase and photoinitiator, wherein the surface-modified cerium oxide ceramic powder is cerium oxide ceramic powder with a dispersant attached to its surface;

[0007] in:

[0008] The total mass of the cerium oxide ceramic powder and the low absorbance powder filler accounts for 40% to 50% of the volume of the cerium oxide ceramic slurry, and the volume ratio of the cerium oxide ceramic powder to the low absorbance powder filler is (1 to 4): 1.

[0009] The volume of the liquid phase of the slurry accounts for 50% to 60% of the volume of the cerium oxide ceramic slurry;

[0010] The dispersant accounts for 1% to 3% of the mass of the cerium oxide ceramic powder;

[0011] The photoinitiator accounts for 1% to 3% of the mass of the liquid phase of the slurry;

[0012] The liquid phase of the slurry comprises, by mass percentage, 40%–50% 4-acryloylmorpholine as a photosensitizing monomer, 10%–20% ethoxypentaerythritol tetraacrylate as a crosslinking agent, and 30%–40% polypropylene glycol-400 as a diluent.

[0013] Furthermore, the particle size of the cerium oxide ceramic powder is 15μm to 20μm.

[0014] Furthermore, the low absorbance powder filler is soluble starch with a particle size of 10μm to 30μm.

[0015] Furthermore, the dispersant is either KD-1 or BYK-180.

[0016] Furthermore, the photoinitiator is one of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide or 2,4,6-trimethylbenzoyl-diphenylphosphine oxide.

[0017] A method for preparing cerium oxide ceramic slurry suitable for photopolymerization 3D printing, comprising:

[0018] Cerium oxide ceramic powder and dispersant were mixed in anhydrous ethanol and then ball-milled. The ball-milled mixture was dried, ground, and then sieved through an 80-150 mesh sieve to obtain surface-modified cerium oxide ceramic powder.

[0019] The surface-modified cerium oxide ceramic powder, the low absorbance powder filler, and the slurry liquid phase are mixed and ball-milled. Finally, a photoinitiator is added, and the mixture is ball-milled again to obtain a cerium oxide ceramic slurry suitable for photopolymerization 3D printing.

[0020] Furthermore, when the cerium oxide ceramic powder and the dispersant are mixed in anhydrous ethanol and then ball-milled, the ball milling rate is 100 rpm to 150 rpm and the ball milling time is 5 h to 10 h.

[0021] When drying the ball-milled mixture, the drying temperature is 50℃~100℃ and the drying time is 2h~6h.

[0022] Furthermore, when the surface-modified cerium oxide ceramic powder, the low absorbance powder filler, and the slurry liquid phase are mixed and ball-milled, the ball milling rate is 100 rpm to 150 rpm and the ball milling time is 5 h to 10 h.

[0023] During the second ball milling, the ball milling rate is 100 rpm to 150 rpm, and the ball milling time is 0.5 h to 1 h.

[0024] A method for molding cerium oxide ceramic slurry suitable for photopolymerization 3D printing, comprising:

[0025] The cerium oxide ceramic slurry was subjected to laser exposure with an energy density of 25 mW / cm². 2 ~37.5mW / cm 2 Photopolymerization 3D printing was performed with exposure time of 7s to 15s and layer thickness of 25μm to 50μm to obtain cerium oxide ceramic blanks.

[0026] The cerium oxide ceramic blank was pyrolyzed under an argon atmosphere according to a set pyrolysis process, and the pyrolysis was completed to obtain a pyrolyzed part. The set pyrolysis process includes the following steps: a first pyrolysis stage, with a pyrolysis temperature of 20℃~200℃, a heating rate of 1℃ / min~1.5℃ / min, and a holding time of 0.5h~1h; a second pyrolysis stage, with a pyrolysis temperature of 200℃~310℃, a heating rate of 0.5℃ / min~1℃ / min, and a holding time of 1h~2h; and a third pyrolysis stage. The three pyrolysis stages are: a pyrolysis temperature of 310℃~410℃, a heating rate of 0.5℃ / min~1℃ / min, and a holding time of 1h~2h; a fourth pyrolysis stage is: a pyrolysis temperature of 410℃~480℃, a heating rate of 0.5℃ / min~1℃ / min, and a holding time of 1h~2h; and a fifth pyrolysis stage is: a pyrolysis temperature of 480℃~600℃, a heating rate of 1℃ / min~1.5℃ / min, and a holding time of 0.5h~1h.

[0027] The pyrolysis part is sintered in air atmosphere, heated to 1550-1650°C at a heating rate of 5°C / min-10°C / min, and held at that temperature for 1-2 hours; then cooled to room temperature at a cooling rate of 3°C / min-5°C / min to obtain cerium oxide ceramic part.

[0028] Compared with the prior art, the present invention has at least the following beneficial effects:

[0029] This invention provides a cerium oxide ceramic slurry suitable for photopolymerization 3D printing. It comprises surface-modified cerium oxide ceramic powder, low-absorbency powder filler, a slurry liquid phase, and a photoinitiator. The slurry liquid phase uses a mixture of a monofunctional photosensitive monomer 4-acryloylmorpholine, a multifunctional crosslinking agent ethoxypentaerythritol tetraacrylate, and a diluent polypropylene glycol-400. The high refractive index of the slurry liquid phase reduces the refractive index difference between the liquid phase and the powder, thereby improving the curing ability and performance of the cerium oxide ceramic slurry. Simultaneously, the introduction of the low-absorbency powder filler reduces the overall absorbance of the ceramic slurry, further enhancing its curing performance. A dispersant is attached to the surface of the cerium oxide ceramic powder, modifying its surface. The modified cerium oxide ceramic powder has a more uniform particle size, reducing agglomeration and making it easier to disperse in the slurry liquid phase. This significantly reduces the viscosity of the ceramic slurry and improves its flowability.

[0030] Furthermore, cerium oxide ceramic powder with a particle size of 15μm to 20μm and low absorbance powder filler soluble starch powder with a particle size of 10μm to 30μm were selected. The higher powder particle size improved the curing ability of the cerium oxide ceramic slurry, while reducing the viscosity of the slurry and improving its fluidity.

[0031] This invention provides a molding method for cerium oxide ceramic slurry suitable for photopolymerization 3D printing. Based on the TG-DSC curve, argon is used as the pyrolysis atmosphere, and five pyrolysis processes are determined: 20℃~200℃, 200℃~310℃, 310℃~410℃, 410℃~480℃, and 480℃~600℃. Appropriate heating rates and holding times are selected to ensure that the structure of the photopolymerized ceramic green body remains intact and crack-free during the pyrolysis process, while simultaneously expelling organic matter from the green body.

[0032] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the specific embodiments of the present invention, the drawings used in the description of the specific embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0034] Figure 1 The test strip blanks, pyrolysis parts, and sintered parts were printed from the slurry prepared in Example 1.

[0035] Figure 2 Examples 2 show the blanks, pyrolysis parts, and sintered parts with three-period minimal curved surface porous structures prepared by slurry printing. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] Example 1

[0038] The preparation method of cerium oxide ceramic slurry suitable for photopolymerization 3D printing is as follows:

[0039] Step 1: Weigh 85g of cerium oxide ceramic powder with an average particle size of 20μm, weigh 1.7g of dispersant KD-11, mix them in 50ml of anhydrous ethanol, add grinding beads, and ball mill in a planetary ball mill at a rate of 120rpm for 8h. Place the ball-milled mixture in an oven at 50℃ for 6h, dry it, grind it, and sieve it through a 100-mesh sieve to obtain surface-modified cerium oxide ceramic powder.

[0040] Step 2: Measure 12 ml of 4-acryloylmorpholine as the photosensitizer, 3.48 ml of ethoxypentaerythritol tetraacrylate as the crosslinking agent, and 8.52 ml of polypropylene glycol-400 as the diluent. Mix them to obtain a slurry liquid premix, wherein the mass ratio of photosensitizer, crosslinking agent and diluent is 50:15:35.

[0041] Step 3: Weigh 6g of soluble starch powder with an average particle size of 20μm. The volume ratio of cerium oxide ceramic powder to soluble starch powder is 3:1.

[0042] Step 4: Add the surface-modified cerium oxide ceramic powder and soluble starch powder to the slurry liquid premix, add ball milling beads, and ball mill in a planetary ball mill at a rate of 150 rpm for 8 hours. Finally, add 0.54 g of photoinitiator 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, and ball mill again for 0.5 h to 1 h to obtain 40 ml of cerium oxide ceramic slurry, wherein the mass of cerium oxide ceramic powder and soluble starch powder accounts for 40% of the volume of cerium oxide ceramic slurry.

[0043] The cerium oxide ceramic slurry prepared in this embodiment was used as the printing slurry. A cerium oxide ceramic blank was printed using photopolymerization 3D printing technology. After heat treatment, a cerium oxide ceramic sample was obtained. The specific operation is as follows:

[0044] 1) Design a long strip structure with a length of 35mm, a width of 5mm, and a height of 4mm using 3D design software.

[0045] 2) The prepared cerium oxide ceramic slurry is injected into the slurry tank, the designed elongated structure is sliced, and the printing parameters are set: the light source wavelength of the photopolymerization 3D printing equipment is 405nm, and the laser exposure energy density is 37.5mW / cm². 2 With an exposure time of 12s and a layer thickness of 25μm, a cerium oxide ceramic blank with a long strip structure was prepared using a photopolymerization 3D printing device.

[0046] 3) The cerium oxide ceramic blank was placed in a pyrolysis furnace for pyrolysis. In an argon atmosphere, the temperature was increased from room temperature to 200℃ at a rate of 1℃ / min, to 310℃ at a rate of 0.5℃ / min, to 410℃ at a rate of 0.5℃ / min, to 480℃ at a rate of 0.5℃ / min, and to 600℃ at a rate of 1℃ / min. The temperature was then maintained at 310℃, 410℃, 480℃, and 600℃ for 1 hour, respectively. The temperature was then reduced to room temperature at a rate of 1℃ / min to obtain a pyrolyzed part with a long strip structure.

[0047] 4) The pyrolysis part was placed in a sintering furnace for sintering. The temperature was increased from room temperature to 1200℃ at a heating rate of 6℃ / min, and then increased to 1600℃ at a heating rate of 3℃ / min. The temperature was held at 1600℃ for 1 hour, and then cooled to room temperature at a cooling rate of 3℃ / min to obtain a cerium oxide ceramic sample with a strip structure.

[0048] Figure 1 The photocurable test specimens and their pyrolysis sintered parts prepared with cerium oxide ceramic slurry in Example 1 are shown in the figure. It can be seen from the figure that the green sample has no obvious delamination and deformation, and the dimensional accuracy is 150μm~250μm; the pyrolysis sample has no obvious deformation and cracking; and the sintered part has no obvious warping and cracking defects.

[0049] Example 2

[0050] The preparation method of cerium oxide ceramic slurry suitable for photopolymerization 3D printing is as follows:

[0051] Step 1: Weigh 57g of cerium oxide ceramic powder with an average particle size of 20μm, weigh 1.14g of dispersant KD-11, mix them in 50ml of anhydrous ethanol, add grinding beads, and ball mill in a planetary ball mill at a rate of 150rpm for 5h. Place the ball-milled mixture in an oven at 80℃ for 4h, dry it, grind it, and sieve it through a 100-mesh sieve to obtain surface-modified cerium oxide ceramic powder.

[0052] Step 2: Measure 12 ml of 4-acryloylmorpholine as the photosensitizer, 3.48 ml of ethoxypentaerythritol tetraacrylate as the crosslinking agent, and 8.52 ml of polypropylene glycol-400 as the diluent. Mix them to obtain a slurry liquid phase premix, wherein the mass ratio of photosensitizer, crosslinking agent and diluent is 50:15:35.

[0053] Step 3: Weigh 12g of soluble starch powder with an average particle size of 20μm. The volume ratio of cerium oxide ceramic powder to soluble starch powder is 1:1.

[0054] Step 4: Add the surface-modified cerium oxide ceramic powder and soluble starch powder to the slurry liquid premix, add ball milling beads, and ball mill in a planetary ball mill at a rate of 150 rpm for 8 hours. Finally, add 0.54 g of photoinitiator 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, and ball mill again for 0.5 h to 1 h to obtain 40 ml of cerium oxide ceramic slurry, wherein the mass of cerium oxide ceramic powder and soluble starch powder accounts for 40% of the volume of cerium oxide ceramic slurry.

[0055] The cerium oxide ceramic slurry prepared in this embodiment was used as the printing slurry. A cerium oxide ceramic blank was printed using photopolymerization 3D printing technology. After heat treatment, a cerium oxide ceramic sample was obtained. The specific operation is as follows:

[0056] 1) A diamond three-period minimal surface structure with a porosity of 70% was designed using 3D design software. The external dimensions are: a cuboid structure with a length of 30mm, a width of 15mm, and a height of 12mm.

[0057] 2) The prepared cerium oxide ceramic slurry is injected into the slurry tank, and the designed three-period minimal curved surface cuboid is sliced. The printing parameters are set as follows: the light source wavelength of the photopolymerization 3D printing equipment is 405nm, and the laser exposure energy density is 30mW / cm². 2With an exposure time of 7 seconds and a layer thickness of 31.25 μm, a cerium oxide ceramic blank with a three-period minimal curved surface structure was prepared using a photopolymerization 3D printing device.

[0058] 3) The cerium oxide ceramic blank was placed in a pyrolysis furnace for pyrolysis. In an argon atmosphere, the temperature was increased from room temperature to 200℃ at a heating rate of 1℃ / min, to 310℃ at a heating rate of 0.7℃ / min, to 410℃ at a heating rate of 0.5℃ / min, to 480℃ at a heating rate of 0.5℃ / min, and to 600℃ at a heating rate of 1℃ / min. The temperature was then held at 310℃, 410℃, 480℃, and 600℃ for 1 hour, respectively. The temperature was then reduced to room temperature at a cooling rate of 1℃ / min, and held at 310℃, 410℃, 480℃, and 600℃ for 1 hour, respectively. The temperature was then reduced to room temperature at a cooling rate of 1℃ / min to obtain a pyrolyzed cuboid with a three-period minimal curved surface structure.

[0059] 4) The pyrolysis part was placed in a sintering furnace for sintering. The temperature was increased from room temperature to 1200℃ at a heating rate of 10℃ / min, and then increased to 1600℃ at a heating rate of 3℃ / min. The temperature was held at 1600℃ for 1 hour, and then cooled to room temperature at a cooling rate of 3℃ / min to obtain a cerium oxide ceramic sample with a cuboid of a three-period minimal curved surface structure.

[0060] Figure 2 The images show photocurable porous samples and their pyrolysis sintered parts prepared from cerium oxide ceramic slurry in Example 2. As can be seen from the figures, the green sample has no obvious delamination or deformation, the pore structure is clear, and the dimensional accuracy is 150μm~250μm; the pyrolysis sample has no obvious cracking; and the sintered part has no obvious warping or cracking defects.

[0061] Example 3

[0062] The preparation method of cerium oxide ceramic slurry suitable for photopolymerization 3D printing is as follows:

[0063] Step 1: Weigh 68.5g of cerium oxide ceramic powder with an average particle size of 18μm, weigh 1.37g of dispersant KD-11, mix them in 50ml of anhydrous ethanol, add grinding beads, and ball mill in a planetary ball mill at a rate of 120rpm for 8h. Place the ball-milled mixture in an oven at 80℃ for 4h, dry it, grind it, and sieve it through a 100-mesh sieve to obtain surface-modified cerium oxide ceramic powder.

[0064] Step 2: Measure 12 ml of 4-acryloylmorpholine as the photosensitizer, 3.48 ml of ethoxypentaerythritol tetraacrylate as the crosslinking agent, and 8.52 ml of polypropylene glycol-400 as the diluent. Mix them to obtain a slurry liquid phase premix, wherein the mass ratio of photosensitizer, crosslinking agent and diluent is 50:15:35.

[0065] Step 3: Weigh 9.6g of soluble starch powder with an average particle size of 25μm. The volume ratio of cerium oxide ceramic powder to soluble starch powder is 1.5:1.

[0066] Step 4: Add the surface-modified cerium oxide ceramic powder and soluble starch powder to the slurry liquid premix, add ball milling beads, and ball mill in a planetary ball mill at a rate of 150 rpm for 8 hours. Finally, add 0.54 g of photoinitiator 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, and ball mill again for 0.5 h to 1 h to obtain 40 ml of cerium oxide ceramic slurry, wherein the mass of cerium oxide ceramic powder and soluble starch powder accounts for 40% of the volume of cerium oxide ceramic slurry.

[0067] The cerium oxide ceramic slurry prepared in this embodiment was used as the printing slurry. A cerium oxide ceramic blank was printed using photopolymerization 3D printing technology. After heat treatment, a cerium oxide ceramic sample was obtained. The specific operation is as follows:

[0068] 1) Design a diamond three-period minimal surface structure with a porosity of 70% using 3D design software. The external dimensions are: a cuboid structure with a length of 30mm, a width of 15mm, and a height of 10mm.

[0069] 2) The prepared cerium oxide ceramic sample was injected into the slurry tank. The designed three-period minimal curved surface cuboid was sliced, and the printing parameters were set as follows: the light source wavelength of the photopolymerization 3D printing equipment was 405nm, and the laser exposure energy density was 30mW / cm². 2 With an exposure time of 8 seconds and a layer thickness of 31.25 μm, a cerium oxide ceramic blank with a three-period minimal curved surface structure was prepared using a photopolymerization 3D printing device.

[0070] 3) The cerium oxide ceramic blank was placed in a pyrolysis furnace for pyrolysis. In an argon atmosphere, the temperature was increased from room temperature to 200℃ at a heating rate of 1℃ / min, to 310℃ at a heating rate of 0.5℃ / min, to 410℃ at a heating rate of 0.5℃ / min, to 480℃ at a heating rate of 1℃ / min, and to 600℃ at a heating rate of 1℃ / min. The temperature was then maintained at 310℃, 410℃, 480℃, and 600℃ for 1 hour, respectively. The temperature was then reduced to room temperature at a cooling rate of 1℃ / min to obtain a pyrolyzed part with a cuboid structure of three-period minimal curved surfaces.

[0071] 4) The pyrolysis part was placed in a sintering furnace for sintering. The temperature was increased from room temperature to 1200℃ at a heating rate of 6℃ / min, and then increased to 1600℃ at a heating rate of 3℃ / min. The temperature was held at 1600℃ for 1 hour, and then cooled to room temperature at a cooling rate of 3℃ / min to obtain a cerium oxide ceramic sample with a cuboid of a three-period minimal curved surface structure.

[0072] The green blanks prepared in this embodiment showed no obvious delamination or deformation, had a clear pore structure, and had a dimensional accuracy of 150μm to 250μm; the pyrolysis samples showed no obvious cracking; and the sintered parts showed no obvious warping or cracking defects.

[0073] Example 4

[0074] The preparation method of cerium oxide ceramic slurry suitable for photopolymerization 3D printing is as follows:

[0075] Step 1: Weigh 128.34g of cerium oxide ceramic powder with an average particle size of 18μm, weigh 3.85g of dispersant BYK-180, mix them in 50ml of anhydrous ethanol, add grinding beads, and ball mill in a planetary ball mill at a rate of 120rpm for 8h. Place the ball-milled mixture in an oven at 50℃ for 6h, dry it, grind it, and sieve it through a 100-mesh sieve to obtain surface-modified cerium oxide ceramic powder.

[0076] Step 2: Measure 10.83 ml of 4-acryloylmorpholine as the photosensitizer, 4.64 ml of ethoxypentaerythritol tetraacrylate as the crosslinking agent, and 8.52 ml of polypropylene glycol-400 as the diluent. Mix them to obtain a slurry liquid premix, wherein the mass ratio of photosensitizer, crosslinking agent and diluent is 45:20:35.

[0077] Step 3: Weigh 9g of soluble starch powder with an average particle size of 15μm. The volume ratio of cerium oxide ceramic powder to soluble starch powder is 3:1.

[0078] Step 4: Add the surface-modified cerium oxide ceramic powder and soluble starch powder to the slurry liquid premix, add ball milling beads, and ball mill in a planetary ball mill at a rate of 150 rpm for 8 hours. Finally, add 0.62 g of photoinitiator phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, and ball mill again for 0.5 h to 1 h to obtain 48 ml of cerium oxide ceramic slurry, wherein the mass of cerium oxide ceramic powder and soluble starch powder together accounts for 50% of the volume of cerium oxide ceramic slurry.

[0079] The cerium oxide ceramic slurry prepared in this embodiment was used as the printing slurry. A cerium oxide ceramic blank was printed using photopolymerization 3D printing technology. After heat treatment, a cerium oxide ceramic sample was obtained. The specific operation is as follows:

[0080] 1) Design a circular structure with a diameter of 20mm and a height of 4mm using 3D design software.

[0081] 2) The prepared cerium oxide ceramic slurry is injected into the slurry tank, the designed circular structure is sliced, and the printing parameters are set: the light source wavelength of the photopolymer 3D printing equipment is 405nm, the laser exposure energy density is 37.5mW / cm2, the exposure time is 12s, and the layer thickness is 25μm. The cerium oxide ceramic blank with a circular structure is prepared by using the photopolymer 3D printing equipment.

[0082] 3) The cerium oxide ceramic blank was placed in a pyrolysis furnace for pyrolysis. In an argon atmosphere, the temperature was increased from room temperature to 200℃ at a heating rate of 1℃ / min, then to 310℃ at a heating rate of 1℃ / min, then to 410℃ at a heating rate of 0.5℃ / min, then to 480℃ at a heating rate of 0.5℃ / min, and finally to 600℃ at a heating rate of 1℃ / min. The temperature was then held at 310℃, 410℃, 480℃, and 600℃ for 1 hour, and then cooled to room temperature at a cooling rate of 1℃ / min to obtain a pyrolyzed part with a circular plate structure.

[0083] 4) The pyrolysis part was placed in a sintering furnace for sintering. The temperature was increased from room temperature to 1200℃ at a heating rate of 8℃ / min, and then increased to 1600℃ at a heating rate of 3℃ / min. The temperature was held at 1600℃ for 1.5h, and then cooled to room temperature at a cooling rate of 3℃ / min to obtain a cerium oxide ceramic sample with a disc structure.

[0084] The green blanks prepared in this embodiment showed no obvious delamination or deformation, and the dimensional accuracy was 150μm to 250μm; the pyrolysis samples showed no obvious deformation or cracking; and the sintered parts showed no obvious warping or cracking defects.

[0085] Example 5

[0086] The preparation method of cerium oxide ceramic slurry suitable for photopolymerization 3D printing is as follows:

[0087] Step 1: Weigh 62.74g of cerium oxide ceramic powder with an average particle size of 15μm, weigh 1.25g of dispersant KD-11, mix them in 50ml of anhydrous ethanol, add grinding beads, and ball mill in a planetary ball mill at a rate of 120rpm for 8h. Place the ball-milled mixture in an oven at 50℃ for 6h, dry it, grind it, and sieve it through a 100-mesh sieve to obtain surface-modified cerium oxide ceramic powder.

[0088] Step 2: Measure 11.24 ml of 4-acryloylmorpholine as the photosensitizer, 4.34 ml of ethoxypentaerythritol tetraacrylate as the crosslinking agent, and 6.82 ml of polypropylene glycol-400 as the diluent. Mix them to obtain a slurry liquid premix, wherein the mass ratio of photosensitizer, crosslinking agent and diluent is 50:20:30.

[0089] Step 3: Weigh 13.2g of soluble starch powder with an average particle size of 25μm. The volume ratio of cerium oxide ceramic powder to soluble starch powder is 1:1.

[0090] Step 4: Add the surface-modified cerium oxide ceramic powder and soluble starch powder to the liquid phase premix of the slurry, add ball milling beads, and ball mill in a planetary ball mill at a rate of 150 rpm for 8 hours. Finally, add 0.54 g of photoinitiator 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, and ball mill again for 0.5 h to 1 h to obtain 40 ml of cerium oxide ceramic slurry, in which the mass of cerium oxide ceramic powder and soluble starch powder accounts for 44% of the volume of cerium oxide ceramic slurry.

[0091] The cerium oxide ceramic slurry prepared in this embodiment was used as the printing slurry. A cerium oxide ceramic blank was printed using photopolymerization 3D printing technology. After heat treatment, a cerium oxide ceramic sample was obtained. The specific operation is as follows:

[0092] 1) Design a circular structure with a diameter of 20mm and a height of 4mm using 3D design software.

[0093] 2) The prepared cerium oxide ceramic slurry is injected into the slurry tank, the designed circular structure is sliced, and the printing parameters are set: the light source wavelength of the photopolymer 3D printing equipment is 405nm, the laser exposure energy density is 25mW / cm2, the exposure time is 12s, and the layer thickness is 25μm. The cerium oxide ceramic blank with a circular structure is prepared by using the photopolymer 3D printing equipment.

[0094] 3) The cerium oxide ceramic blank was placed in a pyrolysis furnace for pyrolysis. In an argon atmosphere, the temperature was increased from room temperature to 200℃ at a heating rate of 1℃ / min, to 310℃ at a heating rate of 0.5℃ / min, to 410℃ at a heating rate of 0.5℃ / min, to 480℃ at a heating rate of 1℃ / min, and to 600℃ at a heating rate of 1℃ / min. The temperature was then held at 310℃, 410℃, 480℃, and 600℃ for 1 hour, respectively. The temperature was then reduced to room temperature at a cooling rate of 1℃ / min to obtain a pyrolyzed part with a circular plate structure.

[0095] 4) The pyrolysis part was placed in a sintering furnace for sintering. The temperature was increased from room temperature to 1200℃ at a heating rate of 6℃ / min, and then increased to 1600℃ at a heating rate of 3℃ / min. The temperature was held at 1600℃ for 1 hour, and then cooled to room temperature at a cooling rate of 3℃ / min to obtain a cerium oxide ceramic sample with a disc structure.

[0096] The green blanks prepared in this embodiment showed no obvious delamination or deformation, and the dimensional accuracy was 150μm to 250μm; the pyrolysis samples showed no obvious deformation or cracking; and the sintered parts showed no obvious warping or cracking defects.

[0097] Example 6

[0098] The preparation method of cerium oxide ceramic slurry suitable for photopolymerization 3D printing is as follows:

[0099] Step 1: Weigh 85g of cerium oxide ceramic powder with an average particle size of 16μm, weigh 1.7g of dispersant KD-11, mix them in 50ml of anhydrous ethanol, add grinding beads, and ball mill in a planetary ball mill at a rate of 150rpm for 5h. Place the ball-milled mixture in an oven at 85℃ for 4h, dry it, grind it, and sieve it through a 100-mesh sieve to obtain surface-modified cerium oxide ceramic powder.

[0100] Step 2: Measure 10.82 ml of 4-acryloylmorpholine as the photosensitizer, 3.48 ml of ethoxypentaerythritol tetraacrylate as the crosslinking agent, and 9.73 ml of polypropylene glycol-400 as the diluent. Mix them to obtain a slurry liquid premix, wherein the mass ratio of photosensitizer, crosslinking agent and diluent is 45:15:40.

[0101] Step 3: Weigh 6g of soluble starch powder with an average particle size of 30μm. The volume ratio of cerium oxide ceramic powder to soluble starch powder is 3:1.

[0102] Step 4: Add the surface-modified cerium oxide ceramic powder and soluble starch powder to the slurry liquid premix, add ball milling beads, and ball mill in a planetary ball mill at a rate of 150 rpm for 8 hours. Finally, add 0.54 g of photoinitiator 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, and ball mill again for 0.5 h to 1 h to obtain 40 ml of cerium oxide ceramic slurry, wherein the mass of cerium oxide ceramic powder and soluble starch powder accounts for 40% of the volume of cerium oxide ceramic slurry.

[0103] The cerium oxide ceramic slurry prepared in this embodiment was used as the printing slurry. A cerium oxide ceramic blank was printed using photopolymerization 3D printing technology. After heat treatment, a cerium oxide ceramic sample was obtained. The specific operation is as follows:

[0104] 1) Design a circular structure with a diameter of 20mm and a height of 4mm using 3D design software.

[0105] 2) The prepared cerium oxide ceramic slurry is injected into the slurry tank, the designed circular structure is sliced, and the printing parameters are set: the light source wavelength of the photopolymer 3D printing equipment is 405nm, the laser exposure energy density is 37.5mW / cm2, the exposure time is 12s, and the layer thickness is 25μm. The cerium oxide ceramic blank with a circular structure is prepared by using the photopolymer 3D printing equipment.

[0106] 3) The cerium oxide ceramic blank was placed in a pyrolysis furnace for pyrolysis. In an argon atmosphere, the temperature was increased from room temperature to 200℃ at a heating rate of 1℃ / min, then to 310℃ at a heating rate of 1℃ / min, then to 410℃ at a heating rate of 0.5℃ / min, then to 480℃ at a heating rate of 1℃ / min, and finally to 600℃ at a heating rate of 1℃ / min. The temperature was then maintained at 310℃, 410℃, 480℃, and 600℃ for 1 hour, respectively. The temperature was then reduced to room temperature at a cooling rate of 1℃ / min to obtain a pyrolyzed part with a circular plate structure.

[0107] 4) The pyrolysis part was placed in a sintering furnace for sintering. The temperature was increased from room temperature to 1200℃ at a heating rate of 8℃ / min, and then increased to 1600℃ at a heating rate of 4℃ / min. The temperature was held at 1600℃ for 1 hour, and then cooled to room temperature at a cooling rate of 3℃ / min to obtain a cerium oxide ceramic sample with a disc structure.

[0108] The green blanks prepared in this embodiment showed no obvious delamination or deformation, and the dimensional accuracy was 150μm to 250μm; the pyrolysis samples showed no obvious deformation or cracking; and the sintered parts showed no obvious warping or cracking defects.

[0109] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0110] Finally, it should be noted that the above-described embodiments are merely specific implementations of the present invention, used to illustrate the technical solutions of the present invention, and not to limit it. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the technical scope disclosed in the present invention, or make equivalent substitutions for some of the technical features; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of protection of the claims.

Claims

1. A cerium oxide ceramic slurry suitable for photopolymerization 3D printing, characterized in that, It includes surface-modified cerium oxide ceramic powder, low absorbance powder filler, slurry liquid phase and photoinitiator, wherein the surface-modified cerium oxide ceramic powder is cerium oxide ceramic powder with a dispersant attached to its surface; in: The total mass of the cerium oxide ceramic powder and the low absorbance powder filler accounts for 40% to 50% of the volume of the cerium oxide ceramic slurry, and the volume ratio of the cerium oxide ceramic powder to the low absorbance powder filler is (1 to 4):

1. The volume of the liquid phase of the slurry accounts for 50% to 60% of the volume of the cerium oxide ceramic slurry; The dispersant accounts for 1% to 3% of the mass of the cerium oxide ceramic powder; The photoinitiator accounts for 1% to 3% of the mass of the liquid phase of the slurry; The liquid phase of the slurry comprises, by mass percentage, 40% to 50% 4-acryloylmorpholine as a photosensitive monomer, 10% to 20% ethoxy pentaerythritol tetraacrylate as a crosslinking agent, and 30% to 40% polypropylene glycol-400 as a diluent. The particle size of the cerium oxide ceramic powder is 15μm~20μm; The low absorbance powder filler is soluble starch with a particle size of 10μm~30μm.

2. The cerium oxide ceramic slurry suitable for photopolymerization 3D printing according to claim 1, characterized in that, The dispersant is either KD-1 or BYK-180.

3. A cerium oxide ceramic slurry suitable for photopolymerization 3D printing according to claim 1, characterized in that, The photoinitiator is one of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide or 2,4,6-trimethylbenzoyl-diphenylphosphine oxide.

4. A method for preparing a cerium oxide ceramic slurry suitable for photopolymerization 3D printing according to any one of claims 1 to 3, characterized in that, include: Cerium oxide ceramic powder and dispersant were mixed in anhydrous ethanol and then ball-milled. The ball-milled mixture was dried, ground, and then sieved through an 80-150 mesh sieve to obtain surface-modified cerium oxide ceramic powder. The surface-modified cerium oxide ceramic powder, the low absorbance powder filler, and the slurry liquid phase are mixed and ball-milled. Finally, a photoinitiator is added, and the mixture is ball-milled again to obtain a cerium oxide ceramic slurry suitable for photopolymerization 3D printing.

5. The method for preparing a cerium oxide ceramic slurry suitable for photopolymerization 3D printing according to claim 4, characterized in that, When the cerium oxide ceramic powder and the dispersant are mixed in anhydrous ethanol and then ball-milled, the ball milling rate is 100 rpm to 150 rpm and the ball milling time is 5 h to 10 h. When drying the ball-milled mixture, the drying temperature is 50℃~100℃ and the drying time is 2h~6h.

6. The method for preparing a cerium oxide ceramic slurry suitable for photopolymerization 3D printing according to claim 4, characterized in that, When the surface-modified cerium oxide ceramic powder, the low absorbance powder filler and the slurry liquid phase are mixed and ball-milled, the ball milling rate is 100 rpm to 150 rpm and the ball milling time is 5 h to 10 h. During the second ball milling, the ball milling rate is 100 rpm to 150 rpm, and the ball milling time is 0.5 h to 1 h.

7. A method for molding cerium oxide ceramic slurry suitable for photopolymerization 3D printing according to any one of claims 1 to 3, characterized in that, include: The cerium oxide ceramic slurry was subjected to laser exposure with an energy density of 25 mW / cm². 2 ~37.5mW / cm 2 Photopolymerization 3D printing was performed with exposure time of 7s~15s and layer thickness of 25μm~50μm to obtain cerium oxide ceramic blanks. The cerium oxide ceramic blank was pyrolyzed under an argon atmosphere according to a set pyrolysis process, and the pyrolysis was completed to obtain the pyrolyzed part. The pyrolysis process is defined as follows: a first pyrolysis stage, with a pyrolysis temperature of 20℃~200℃, a heating rate of 1℃ / min~1.5℃ / min, and a holding time of 0.5h~1h; a second pyrolysis stage, with a pyrolysis temperature of 200℃~310℃, a heating rate of 0.5℃ / min~1℃ / min, and a holding time of 1h~2h; a third pyrolysis stage, with a pyrolysis temperature of 310℃~410℃, a heating rate of 0.5℃ / min~1℃ / min, and a holding time of 1h~2h; a fourth pyrolysis stage, with a pyrolysis temperature of 410℃~480℃, a heating rate of 0.5℃ / min~1℃ / min, and a holding time of 1h~2h; and a fifth pyrolysis stage, with a pyrolysis temperature of 480℃~600℃, a heating rate of 1℃ / min~1.5℃ / min, and a holding time of 0.5h~1h. The pyrolysis part is sintered in air atmosphere, heated to 1550~1650℃ at a heating rate of 5℃ / min~10℃ / min, and held for 1h~2h; then cooled to room temperature at a cooling rate of 3℃ / min~5℃ / min to obtain cerium oxide ceramic part.

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