A photocurable ceramic core paste and a method for preparing the same

Abstract

This invention relates to a photocurable ceramic core slurry and its preparation method. The raw materials of the photocurable ceramic core slurry include 40-70 parts by weight of ceramic matrix powder, 10-15 parts by weight of mineralizer, 6-20 parts by weight of viscosity modifier, 3-10 parts by weight of curing performance modifier, 10-20 parts by weight of slurry main solvent, 5-10 parts by weight of dispersant, and 1-3 parts by weight of photoinitiator. The viscosity modifier is one or more of 1,6-hexanediol diacrylate, dipropylene glycol diacrylate, and propoxylated neopentyl glycol diacrylate. The curing performance modifier is one or more of ethoxylated trimethylolpropane triacrylate, trimethylolpropane triacrylate, and bis(trimethylolpropane)tetraacrylate. The slurry main solvent is one or more of 2-phenoxyethyl acrylate, isobornyl methacrylate, isooctyl acrylate, and isodecanyl acrylate. This invention can prepare a low-viscosity, high-solids-content photocurable ceramic core slurry.

Description

Technical Field

[0001] This invention relates to the field of photocurable 3D printing ceramic preparation technology, and in particular to a photocurable ceramic core slurry and its preparation method. Background Technology

[0002] With advancements in aviation technology, higher standards have been set for the temperature resistance of engine turbine blades. Currently, both domestic and international manufacturers are designing hollow turbine blades with complex cooling channels to improve the cooling efficiency of engine turbine inlets. Ceramic cores, as key components of the internal cooling channels of turbine blades, are exhibiting increasingly complex structures.

[0003] Traditional methods for manufacturing ceramic cores mainly include gel casting and hot-press injection molding. Currently, simple ceramic cores are generally manufactured using hot-press injection molding, which suffers from problems such as mold production, long cycle times, and high costs, and cannot produce ceramic cores with complex structures. Stereolithography 3D printing uses photopolymerization reactions for rapid prototyping. Compared with traditional molding processes, stereolithography 3D printing has advantages such as high forming accuracy, short cycle times, and low production costs. Therefore, stereolithography 3D printing technology provides a new approach for fabricating complex ceramic core structures.

[0004] Currently, complex ceramic cores can be fabricated using stereolithography 3D printing technology. However, the ceramic core blanks are prone to defects such as deformation and significant shrinkage after sintering, limiting their wider application. The key to photopolymerization 3D printing of ceramic cores is the preparation of the ceramic slurry. Studies have shown that increasing the solid content can reduce the shrinkage rate and defect rate of the ceramic blank, but as the solid content increases, the slurry viscosity increases, and the curing performance decreases.

[0005] In summary, there is an urgent need for a high-solids-content, low-viscosity photopolymerizable ceramic core slurry to promote the development of photopolymerizable 3D printing technology in the field of ceramic cores. Summary of the Invention

[0006] In view of this, the present invention provides a photocurable ceramic core slurry and its preparation method, the main purpose of which is to prepare a photocurable ceramic core slurry with high solid content and low viscosity.

[0007] To achieve the above objectives, the present invention mainly provides the following technical solutions:

[0008] On one hand, embodiments of the present invention provide a method for preparing a photocurable ceramic core slurry, wherein the raw materials are mixed to obtain the photocurable ceramic core slurry; wherein, by weight, the raw materials include: 40-70 parts by weight of ceramic matrix powder, 10-15 parts by weight of mineralizer, 6-20 parts by weight of viscosity modifier, 3-10 parts by weight of curing performance modifier, 10-20 parts by weight of slurry main solvent, 5-10 parts by weight of dispersant, and 1-3 parts by weight of photoinitiator; wherein, the viscosity modifier is one or more of 1,6-hexanediol diacrylate, dipropylene glycol diacrylate, and propoxylated neopentyl glycol diacrylate; the curing performance modifier is one or more of ethoxylated trimethylolpropane triacrylate, trimethylolpropane triacrylate, and bis(trimethylolpropane)tetraacrylate; and the slurry main solvent is one or more of 2-phenoxyethyl acrylate, isobornyl methacrylate, isooctyl acrylate, and isodecanyl acrylate.

[0009] Preferably, the dispersant is one or more of BYK9076, KOS110, BYK111, KOS163, and BYK180; and / or the photoinitiator is one or two of diphenyl-(2,4,6-trimethylbenzoyl)phosphorus oxydioxide and photoinitiator 819; and / or the viscosity of the viscosity modifier is 10-20 MPa·s; and / or the viscosity of the curing performance modifier is 20-50 MPa·s; and / or the viscosity of the dispersant is 30-90 MPa·s; and / or the viscosity of the slurry bulk solvent is 1-10 MPa·s; and / or the viscosity modifier is a difunctional resin with a molecular weight range of 220-330; and / or the curing performance modifier is a polyfunctional resin with a molecular weight range of 280-470; and / or the slurry bulk solvent is a monofunctional resin with a molecular weight range of 115-215. And / or the content of the viscosity modifier is 1-6 parts by weight higher than that of the curing performance modifier.

[0010] Preferably, the ceramic matrix powder is selected from one or both of SiO2 particles and Al2O3 particles; preferably, the particle size of SiO2 particles is 1-100μm and the particle size of Al2O3 particles is 50-100μm.

[0011] Preferably, the mineralizer is selected from one or both of Al2O3 particles and ZrO2 particles; preferably, the particle size of Al2O3 particles is 0.1-20 μm and the particle size of ZrO2 particles is 10-100 nm.

[0012] Preferably, the step of mixing the raw materials includes:

[0013] Preparation of pre-formed solid powder: ceramic matrix powder and mineralizer are mixed to obtain pre-formed solid powder;

[0014] Preparation of pre-prepared liquid solvent: Viscosity modifier, curing performance modifier and dispersant are mixed and treated to obtain pre-prepared liquid solvent;

[0015] Preparation of slurry premix: The pre-prepared solid powder, pre-prepared liquid solvent, and slurry bulk solvent are mixed and treated to obtain slurry premix;

[0016] Ball milling treatment: Add photoinitiator and ball milling beads to the slurry premix and perform ball milling treatment to obtain photocurable ceramic core slurry.

[0017] Preferably, the photocurable ceramic core slurry comprises 20-30% liquid phase and 60-70% solid phase by volume fraction.

[0018] Preferably, in the step of preparing the pre-formed solid powder: first, a ceramic matrix powder with a large particle size is added, then a mineralizer with a small particle size is added, and then the mixture is mixed to obtain the pre-formed solid powder.

[0019] Preferably, in the step of preparing the slurry premix: the pre-prepared solid powder is added to the pre-prepared liquid solvent in batches, and then the main solvent of the slurry is added and mechanically mixed to obtain the slurry premix.

[0020] Preferably, in the ball milling step: the grinding balls are equal-diameter grinding balls; and / or the mass of the added grinding balls is 1 / 3-1 of the total mass of the slurry premix and the photoinitiator, preferably, the mass of the added grinding balls is 2 / 3 of the total mass of the slurry premix and the photoinitiator; and / or the ball milling speed is 200-600 rpm / min, and the ball milling time is 1.5-3.5 hours.

[0021] On the other hand, embodiments of the present invention provide a photocurable ceramic core slurry, wherein the photocurable ceramic core slurry is prepared by the preparation method of the photocurable ceramic core slurry described in any one of the above claims; preferably, the solid content of the photocurable ceramic core slurry is 55-65 vol%; preferably, the viscosity range of the photocurable ceramic core slurry is 2000 MPa·s-6000 MPa·s.

[0022] In another aspect, embodiments of the present invention provide a method for preparing a photocurable ceramic core, which includes the following steps:

[0023] Step 1) Perform photocuring 3D printing on the above-mentioned photocurable ceramic core slurry to obtain a photocurable ceramic core blank; preferably, the printing layup speed is 10-20 m / s and the printing layer thickness is 100-200 micrometers.

[0024] Step 2) The photocurable ceramic core blank is degreased and sintered to obtain the photocurable ceramic core.

[0025] In another aspect, embodiments of the present invention provide a photocurable ceramic core, characterized in that the photocurable ceramic core is prepared by the above-described method for preparing a photocurable ceramic core.

[0026] Compared with the prior art, the photocurable ceramic core slurry and its preparation method of the present invention have at least the following beneficial effects:

[0027] On one hand, embodiments of the present invention provide a method for preparing a photocurable ceramic core slurry, wherein the raw materials are mixed to obtain the photocurable ceramic core slurry; by weight, the raw materials include: 40-70 parts by weight of ceramic matrix powder, 10-15 parts by weight of mineralizer, 6-20 parts by weight of viscosity modifier, 3-10 parts by weight of curing performance modifier, 10-20 parts by weight of slurry main solvent, 5-10 parts by weight of dispersant, and 1-3 parts by weight of photoinitiator; wherein the viscosity modifier is one or more of 1,6-hexanediol diacrylate, dipropylene glycol diacrylate, and propoxylated neopentyl glycol diacrylate; the curing performance modifier is one or more of ethoxylated trimethylolpropane triacrylate, trimethylolpropane triacrylate, and bis(trimethylolpropane)tetraacrylate; and the slurry main solvent is one or more of 2-phenoxyethyl acrylate, isobornyl methacrylate, isooctyl acrylate, and isodecanyl acrylate. In this invention, curing performance regulators, viscosity modifiers, and slurry main solvents are selected as raw materials. Based on the different functional groups in various regulators, the molecular weight is adjusted to control the slurry (resins can be classified into monofunctional, difunctional, and multifunctional resins according to the number of reactive groups in each molecule. The number of functional groups in each molecule is called functionality; the more functional groups that can participate in the photocuring reaction, the greater the functionality, the higher the photocuring reactivity, and the faster the photocuring rate. As the number of functional groups in the resin increases, its molecular weight also increases accordingly, increasing intermolecular interactions and thus viscosity), thereby improving the curability of the slurry, reducing its viscosity, and increasing its solid content.

[0028] Furthermore, this embodiment of the invention provides a method for preparing a photocurable ceramic core slurry, comprising the following steps: mixing ceramic matrix powder and a mineralizer to obtain a pre-formed solid phase powder; mixing a viscosity modifier, a curing performance modifier, and a dispersant to obtain a pre-formed liquid phase solvent; mixing the pre-formed solid phase powder, the pre-formed liquid phase solvent, and the slurry bulk solvent to obtain a slurry premix; adding a photoinitiator and milling beads to the slurry premix, and performing ball milling to obtain a photocurable ceramic core slurry. Here, the present invention first utilizes the multi-directional cross-linking effect exhibited by curing performance modifiers and viscosity modifiers on the slurry (the photoinitiator in the ceramic slurry absorbs energy under a certain light source, undergoes a photolysis reaction, generates active free radicals, activates the corresponding monomer / oligomer double bonds or epoxy groups, activates and initiates the polymerization of oligomers and active monomers, and the small molecules undergo cross-linking reactions to polymerize into high-molecular-weight cured products. Viscosity modifiers and curing performance modifiers are multifunctional monomers; a single monomer structure contains multiple double bonds or epoxy groups that can undergo polymerization reactions. During polymerization, the double bonds open randomly, releasing free radicals from different...) The cross-linking reaction occurs at specific locations, exhibiting multi-directional cross-linking, ensuring the curing performance of the slurry. Then, the single cross-linking effect of the slurry's main solvent increases the repulsive force between ceramic particles in the slurry, reducing the slurry's viscosity and increasing its solid content. (When free radical monomers or oligomers do not undergo polymerization, the distance between the oligomer and the diluent is determined by van der Waals forces. The viscosity modifier, curing performance modifier, and main slurry solvent used in this invention are free radical monomers. The dispersant in the slurry affects the solid particles through van der Waals forces. The addition of the main slurry solvent increases the effect of van der Waals forces, leading to the dispersion of ceramic particles and a reduction in viscosity.) Furthermore, this invention uses curing performance modifiers, viscosity modifiers, and main slurry solvents of different viscosities and their addition order. First, the curing performance modifier and viscosity modifier with higher viscosity are added, followed by the main slurry solvent with lower viscosity. This effectively dilutes and balances the viscosity of the slurry's liquid phase, reduces powder accumulation during slurry preparation, and allows solid particles to be uniformly dispersed within the slurry, achieving the preparation of a high-solids-content ceramic slurry.

[0029] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of a method for preparing a photocurable ceramic core slurry according to an embodiment of the present invention;

[0031] Figure 2 These are physical images of the photocurable ceramic core slurry prepared according to the embodiments and comparative examples of the present invention.

[0032] Figure 3 This is a physical image of the printed ceramic core blank from Example 1.

[0033] Figure 4 This is a picture of the actual ceramic core blank printed in Comparative Example 3. Detailed Implementation

[0034] To further illustrate the technical means and effects adopted by the present invention to achieve the intended purpose, the specific embodiments, structures, features, and effects according to the present invention will be described in detail below with reference to the accompanying drawings and preferred embodiments. In the following description, different "embodiments" or "embodiments" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0035] Therefore, in order to prepare high-solids content slurries with good performance, the inventors of this invention have discovered through research that by changing the type and amount of viscosity modifiers, curing performance modifiers, and main solvents in the slurry, the distribution state of particles in the slurry and the crosslinking during curing can be altered. This allows for the reduction of ceramic particle aggregation and wettability while ensuring slurry curing, thereby increasing the solids content of the slurry.

[0036] The main solution of the present invention is as follows:

[0037] This invention provides a method for preparing a photocurable ceramic core slurry, wherein the raw materials are mixed to obtain the photocurable ceramic core slurry; wherein, by weight, the raw materials include: 40-70 parts by weight of ceramic matrix powder, 10-15 parts by weight of mineralizer, 6-20 parts by weight of viscosity modifier, 3-10 parts by weight of curing performance modifier, 10-20 parts by weight of slurry main solvent, 5-10 parts by weight of dispersant, and 1-3 parts by weight of photoinitiator; wherein, the viscosity modifier is one or more of 1,6-hexanediol diacrylate, dipropylene glycol diacrylate, and propoxylated neopentyl glycol diacrylate; the curing performance modifier is one or more of ethoxylated trimethylolpropane triacrylate, trimethylolpropane triacrylate, and bis(trimethylolpropane)tetraacrylate; and the slurry main solvent is one or more of 2-phenoxyethyl acrylate, isobornyl methacrylate, isooctyl acrylate, and isodecanyl acrylate.

[0038] The viscosity modifier is a difunctional resin with a molecular weight range of 220-330; and / or the curing performance modifier is a polyfunctional resin with a molecular weight range of 280-470; and / or the main solvent of the slurry is a monofunctional resin with a molecular weight range of 115-215.

[0039] Regarding the above-mentioned scheme, it should be noted that the preparation method of the photocurable ceramic core slurry provided in this embodiment of the invention uses curing performance regulators, viscosity regulators, and slurry main solvents as raw materials. Here, based on the different functional groups in various regulators, the slurry is regulated by synergistic molecular weight (the molar mass of each component of the resin, usually expressed as molecular weight). (Resins can be classified into monofunctional, difunctional, and multifunctional resins according to the number of reactive groups contained in each molecule. The number of functional groups in each molecule is called functionality. The more functional groups that can participate in the photocuring reaction, the greater the functionality, the higher the photocuring reactivity, and the faster the photocuring rate. As the number of functional groups in the resin increases, its molecular weight also increases accordingly, increasing intermolecular interactions and thus increasing viscosity.) This improves the curability of the slurry, reduces its viscosity, and increases its solid content.

[0040] Preferably, the dispersant is one or more of BYK9076, KOS110, BYK111, KOS163, and BYK180. Preferably, the photoinitiator is one or more of diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxychloride and photoinitiator 819.

[0041] Preferably, the ceramic matrix powder is selected from one or both of SiO2 particles and Al2O3 particles; more preferably, the particle size of SiO2 particles is 1-100μm and the particle size of Al2O3 particles is 50-100μm.

[0042] Preferably, the mineralizer is selected from one or both of Al2O3 particles and ZrO2 particles; more preferably, the particle size of Al2O3 particles is 0.1-20 μm and the particle size of ZrO2 particles is 10-100 nm.

[0043] Preferably, for the preparation method of the photocurable ceramic core slurry, see [reference needed]. Figure 1 As shown, it includes the following steps:

[0044] Preparation of pre-formed solid powder: The ceramic matrix powder and the mineralizer are uniformly mixed to obtain the pre-formed solid powder.

[0045] In the preparation of the pre-formed solid powder, a ceramic matrix powder with a larger particle size is added first, followed by a mineralizer with a smaller particle size, and then the mixture is mixed to obtain the pre-formed solid powder.

[0046] Preparation of pre-prepared liquid solvent: Viscosity modifier, curing performance modifier and dispersant are mixed evenly to obtain pre-prepared liquid solvent.

[0047] The viscosity of the viscosity modifier is 10-20 MPa·s.

[0048] The viscosity of the curing performance modifier is 20-50 MPa·s.

[0049] The viscosity of the dispersant is 30-90 MPa·s.

[0050] The viscosity modifier is a bifunctional resin with a molecular weight range of 220-330;

[0051] The curing performance modifier is a multifunctional resin with a molecular weight range of 280-470;

[0052] Preparation of slurry premix: The pre-prepared solid powder is added to the pre-prepared liquid solvent in batches, and then the main solvent of the slurry is added. The slurry premix is ​​obtained by mechanical mixing.

[0053] The viscosity of the main solvent in the slurry is 1-10 MPa·s.

[0054] The main solvent of the slurry is a monofunctional resin with a molecular weight range of 115-215.

[0055] Ball milling: A photoinitiator and equal-diameter milling balls are added to the slurry premix, and the mixture is then ball-milled to obtain a photocurable ceramic core slurry.

[0056] The ball milling process was carried out using a planetary ball mill. The ball milling speed was 200-600 rpm / min, the ball milling time was 1.5-3.5 h, and the mass of the equal-diameter ball milling beads was 2 / 3 of the total mass of the slurry premix and photoinitiator.

[0057] The photocurable ceramic core slurry comprises 20-30% liquid phase and 60-70% solid phase by volume fraction.

[0058] Here, the steps need to be explained:

[0059] (1) The method for preparing a photocurable ceramic core slurry provided in this embodiment of the invention firstly relies on the multi-directional cross-linking effect between the curing performance regulator and the viscosity regulator on the slurry to ensure the curing performance of the slurry. Then, the single cross-linking effect of the slurry's main solvent is used to increase the repulsive force between ceramic particles in the slurry, thereby reducing the viscosity of the slurry and increasing its solid content.

[0060] (2) In this invention, different viscosity curing performance modifiers, viscosity modifiers, slurry main solvents and addition order are selected. First, the curing performance modifiers and viscosity modifiers with higher viscosity are added, and then the slurry main solvent with lower viscosity is added. This can effectively dilute and balance the viscosity of the liquid phase components of the slurry, reduce the degree of powder accumulation during the preparation of the slurry, and allow solid particles to be evenly dispersed in the slurry, so as to realize the preparation of high solid content ceramic slurry.

[0061] The present invention will be further illustrated below with specific embodiments:

[0062] Example 1

[0063] This embodiment prepares a photocurable ceramic core slurry, wherein the raw materials and their weight parts are as follows: 55 parts by weight of ceramic matrix powder, 10 parts by weight of mineralizer, 2 parts by weight of photoinitiator, 9 parts by weight of viscosity modifier, 3 parts by weight of curing performance modifier, 12 parts by weight of slurry main solvent, and 9 parts by weight of dispersant. The ceramic matrix powder is SiO2 particles, the mineralizer is Al2O3 particles and ZrO2 particles in a mass ratio of 3:7, the particle size of SiO2 particles is 70 μm, the particle size of Al2O3 particles is 15 μm, and the particle size of ZrO2 particles is 10 nm; the curing performance modifier is trimethylolpropane triacrylate with a molecular weight of 296, the viscosity modifier is 1,6-hexanediol diacrylate with a molecular weight of 224.254, the slurry main solvent is isodecyl acrylate with a molecular weight of 116.12, the dispersant is BYK111, and the photoinitiator is 819. The viscosity of the curing performance modifier is 50 MPa·s, the viscosity of the viscosity modifier is 10 MPa·s, the viscosity of the slurry's main solvent is 1 MPa·s, and the viscosity of the dispersant is 40 MPa·s.

[0064] The method for preparing the photocurable ceramic core slurry in this embodiment includes the following steps:

[0065] 1) Mix ceramic powder and mineralizer evenly to obtain pre-made solid powder.

[0066] 2) Mix the curing performance modifier, viscosity modifier and dispersant evenly to obtain a pre-prepared liquid phase solvent.

[0067] 3) The pre-prepared solid powder is added to the liquid solvent in batches, and then the main solvent of the slurry is added to it. After mechanical mixing, the slurry premix is ​​obtained.

[0068] 4) Add photoinitiator and 2 / 3 of the total mass of the slurry equal diameter ball milling beads to the slurry premix, and ball mill at 400 rpm / min for 2 hours to obtain photocurable ceramic core slurry.

[0069] Example 2

[0070] This embodiment prepares a photocurable ceramic core slurry, which differs from Embodiment 1 in that the raw materials and weight parts of this embodiment are as follows: 55 parts by weight of ceramic matrix powder, 10 parts by weight of mineralizer, 2 parts by weight of photoinitiator, 8 parts by weight of viscosity modifier, 4 parts by weight of curing performance modifier, 12 parts by weight of slurry main solvent, and 9 parts by weight of dispersant.

[0071] Everything else is completely consistent with Example 1.

[0072] Example 3

[0073] This embodiment prepares a photocurable ceramic core slurry, which differs from Embodiment 1 in that the raw materials and weight parts of this embodiment are as follows: 55 parts by weight of ceramic matrix powder, 10 parts by weight of mineralizer, 2 parts by weight of photoinitiator, 6 parts by weight of viscosity modifier, 6 parts by weight of curing performance modifier, 12 parts by weight of slurry main solvent, and 9 parts by weight of dispersant.

[0074] Everything else is completely consistent with Example 1.

[0075] Example 4

[0076] This embodiment prepares a photocurable ceramic core slurry, which differs from Example 1 in that the viscosity modifier is tripropylene glycol diacrylate with a molecular weight of 300.

[0077] Everything else is completely consistent with Example 1.

[0078] Example 5

[0079] This embodiment prepares a photocurable ceramic core slurry, which differs from Example 1 in that:

[0080] The method for preparing the photocurable ceramic core slurry in this embodiment includes the following steps:

[0081] 1) Mix ceramic powder and mineralizer evenly to obtain pre-made solid powder.

[0082] 2) Mix the curing performance modifier, viscosity modifier, dispersant, and slurry main solvent evenly to obtain a pre-prepared liquid phase solvent.

[0083] 3) The pre-prepared solid powder is added to the liquid solvent in sequence and then mechanically mixed to obtain a slurry premix.

[0084] 4) Add photoinitiator and 2 / 3 of the total mass of the slurry equal diameter ball milling beads to the slurry premix, and ball mill at 400 rpm / min for 2 hours to obtain photocurable ceramic core slurry.

[0085] Everything else is completely consistent with Example 1.

[0086] Comparative Example 1

[0087] Comparative Example 1 prepared a photocurable ceramic core slurry; the raw materials and their weight parts are as follows: 45 parts by weight of ceramic matrix powder, 10 parts by weight of mineralizer, 2 parts by weight of photoinitiator, 10 parts by weight of viscosity modifier, 30 parts by weight of curing performance modifier, and 9 parts by weight of dispersant. The ceramic matrix powder is SiO2 particles, the mineralizer is Al2O3 particles and ZrO2 particles in a mass ratio of 1:9, the particle size of SiO2 particles is 70 μm, the particle size of Al2O3 particles is 15 μm, and the particle size of ZrO2 particles is 20 nm; the curing performance modifier is trimethylolpropane triacrylate with a molecular weight of 296, the viscosity modifier is 1,6-hexanediol diacrylate with a molecular weight of 224.254, the dispersant is BYK111, and the photoinitiator is photoinitiator 819. The viscosity of the curing performance modifier is 50 MPa·s, the viscosity of the viscosity modifier is 10 MPa·s, and the viscosity of the dispersant is 40 MPa·s.

[0088] The preparation method of the photocurable ceramic core slurry of Comparative Example 1 includes the following steps:

[0089] 1) Mix ceramic powder and mineralizer evenly to obtain pre-made solid powder.

[0090] 2) Mix the curing performance modifier, viscosity modifier and dispersant evenly to obtain a pre-prepared liquid phase solvent.

[0091] 3) The pre-prepared solid powder is added to the liquid solvent in sequence and then mechanically mixed to obtain a slurry premix.

[0092] 4) Add photoinitiator and 2 / 3 of the total mass of the slurry equal diameter ball milling beads to the slurry premix, and ball mill at 400 rpm / min for 2 hours to obtain photocurable ceramic core slurry.

[0093] Comparative Example 2

[0094] Comparative Example 2 prepared a photocurable ceramic core slurry. The raw materials and their mass fractions were as follows: 45 parts by weight of ceramic matrix powder, 10 parts by weight of mineralizer, 2 parts by weight of photoinitiator, 30 parts by weight of viscosity modifier, 10 parts by weight of curing performance modifier, and 9 parts by weight of dispersant. The ceramic matrix powder was SiO2 particles, the mineralizer was Al2O3 particles and ZrO2 particles in a mass ratio of 2:8, the particle size of SiO2 particles was 70 μm, the particle size of Al2O3 particles was 15 μm, and the particle size of ZrO2 particles was 20 nm; the curing performance modifier was trimethylolpropane triacrylate with a molecular weight of 296, the viscosity modifier was 1,6-hexanediol diacrylate with a molecular weight of 224.254, the dispersant was BYK111, and the photoinitiator was photoinitiator 819. The viscosity of the curing performance modifier is 50 MPa·s, the viscosity of the viscosity modifier is 10 MPa·s, and the viscosity of the dispersant is 40 MPa·s.

[0095] The preparation method of the photocurable ceramic core slurry in Comparative Example 2 specifically includes the following steps:

[0096] 1) Mix ceramic powder and mineralizer evenly to obtain pre-made solid powder.

[0097] 2) Mix the curing performance modifier, viscosity modifier and dispersant evenly to obtain a pre-prepared liquid phase solvent.

[0098] 3) The pre-prepared solid powder is added to the liquid solvent in sequence and then mechanically mixed to obtain a slurry premix.

[0099] 4) Add photoinitiator and 2 / 3 of the total mass of the slurry equal diameter ball milling beads to the slurry premix, and ball mill at 400 rpm / min for 2 hours to obtain photocurable ceramic core slurry.

[0100] Comparative Example 3

[0101] Comparative Example 3 prepared a photocurable ceramic core slurry. The raw materials and their mass fractions were as follows: 55 parts by weight of ceramic matrix powder, 10 parts by weight of mineralizer, 2 parts by weight of photoinitiator, 18 parts by weight of viscosity modifier, 6 parts by weight of curing performance modifier, and 9 parts by weight of dispersant. The ceramic matrix powder was SiO2 particles, the mineralizer was Al2O3 particles and ZrO2 particles in a mass ratio of 3:7, the particle size of SiO2 particles was 70 μm, the particle size of Al2O3 particles was 15 μm, and the particle size of ZrO2 particles was 20 nm. The curing performance modifier was trimethylolpropane triacrylate with a molecular weight of 296, the viscosity modifier was 1,6-hexanediol diacrylate with a molecular weight of 224.254, the dispersant was BYK111, and the photoinitiator was photoinitiator 819. The viscosity of the curing performance modifier is 50 MPa·s, the viscosity of the viscosity modifier is 10 MPa·s, and the viscosity of the dispersant is 40 MPa·s.

[0102] The preparation method of the photocurable ceramic core slurry in Comparative Example 3 specifically includes the following steps:

[0103] 1) Mix ceramic powder and mineralizer evenly to obtain pre-made solid powder.

[0104] 2) Mix the curing performance modifier, viscosity modifier and dispersant evenly to obtain a pre-prepared liquid phase solvent.

[0105] 3) The pre-prepared solid powder is added to the liquid solvent in sequence and then mechanically mixed to obtain a slurry premix.

[0106] 4) Add photoinitiator and 2 / 3 of the total mass of the slurry equal diameter ball milling beads to the slurry premix, and ball mill at 400 rpm / min for 2 hours to obtain photocurable ceramic core slurry.

[0107] The properties of the photocurable ceramic core slurries prepared in Examples 1-5 and Comparative Examples 1-3 were tested. The performance test structures are shown in Table 1. A viscosity diagram of the photocurable ceramic core slurry is shown below. Figure 2 As stated above.

[0108] Table 1

[0109]

[0110] Note: The total number of functional groups in Table 1 refers to the number of functional groups after the slurry is prepared.

[0111] As can be seen from Table 1:

[0112] (1) The performance of the photocurable ceramic core slurry prepared in the embodiments of the present invention is significantly better than that of the comparative example.

[0113] (2) The multi-directional cross-linking effect between the curing performance modifier and the viscosity modifier on the slurry ensures the curing performance of the slurry. The multi-directional cross-linking effect between the curing performance modifier and the viscosity modifier on the slurry ensures the curing performance of the slurry. The single cross-linking effect of the slurry's main solvent increases the repulsive force between ceramic particles in the slurry and reduces the viscosity of the slurry. When the weight part of the viscosity modifier is 1-6 parts more than that of the curing performance modifier, it can better promote the synergistic effect between the curing performance modifier, the viscosity modifier, and the slurry's main solvent. By utilizing the synergistic effect between the curing performance modifier, the viscosity modifier, and the slurry's main solvent, a special slurry for high-solids-content, low-viscosity photocurable ceramic cores can be prepared.

[0114] (3) When preparing photocurable ceramic core slurry, first add curing performance regulator and viscosity regulator with higher viscosity, and then add slurry main solvent with lower viscosity. This can effectively dilute and balance the viscosity of the liquid phase components of the slurry, reduce the degree of powder accumulation during the preparation of the slurry, and allow solid particles to be evenly dispersed in the slurry, so as to achieve the preparation of high solid content ceramic slurry (see the comparison of Example 1 and Example 5).

[0115] (4) Combination Figure 2 As shown in Table 1, at a solid content of 65 vol%, the curing effect and viscosity of the slurry in Comparative Example 3 were worse than those in the Example 1. The main reason is that the slurry's main solvent, a monofunctional resin, was added in the examples of this invention. A simple monofunctional resin can only produce a linear polymer during curing and does not undergo cross-linking. Therefore, the addition of the main solvent can reduce the photocuring reactivity of the slurry, decrease the photocuring rate, and improve the curing effect. Simultaneously, the molecular weight of the main solvent is lower than that of the curing performance modifier and viscosity modifier, which can reduce the viscosity of the slurry.

[0116] Example 6

[0117] The photocurable ceramic core slurries prepared in Example 1 and Comparative Example 3 were subjected to photocurable printing, with the same photocurable 3D printing parameters set: curing thickness of 100 μm and curing power of 25 mW / cm². 2 The curing time for a single layer is 15 seconds. The slurry is cured using a photopolymer 3D printing device to obtain a ceramic core blank sample.

[0118] in, Figure 3 This is a physical image of the printed ceramic core blank from Example 1. Figure 4 This is a photograph of the actual printed ceramic core blank (scale 3). Figure 3 and Figure 4It can be seen that the ceramic core blanks printed using the high solids content and low viscosity photocurable ceramic core slurry of the present invention have good integrity; while the ceramic core blanks printed using the photocurable ceramic core slurry prepared in Comparative Example 3 have poor integrity.

[0119] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A method for preparing a photocurable ceramic core slurry, characterized in that, The raw materials are mixed to obtain a photocurable ceramic core slurry; wherein, By weight, the raw materials include: 40-70 parts by weight of ceramic matrix powder, 10-15 parts by weight of mineralizer, 6-20 parts by weight of viscosity modifier, 3-10 parts by weight of curing performance modifier, 10-20 parts by weight of slurry main solvent, 5-10 parts by weight of dispersant, and 1-3 parts by weight of photoinitiator. The viscosity modifier is one or more of 1,6-hexanediol diacrylate, tripropylene glycol diacrylate, and propoxylated neopentyl glycol diacrylate. The curing performance modifier is one or more of ethoxylated trimethylolpropane triacrylate, trimethylolpropane triacrylate, and bis(trimethylolpropane tetraacrylate). The main solvent of the slurry is one or more of 2-phenoxyethyl acrylate, isobornyl methacrylate, isooctyl acrylate, and isodecyl acrylate. The viscosity modifier content is 1-6 parts by weight higher than the curing performance modifier content. Wherein, the viscosity of the viscosity modifier is 10-20 MPa·s; the viscosity of the curing performance modifier is 20-50 MPa·s; and the viscosity of the main solvent of the slurry is 1-10 MPa·s. The step of mixing the raw materials includes: Preparation of pre-formed solid powder: ceramic matrix powder and mineralizer are mixed to obtain pre-formed solid powder; Preparation of pre-prepared liquid solvent: Viscosity modifier, curing performance modifier and dispersant are mixed and treated to obtain pre-prepared liquid solvent; Preparation of slurry premix: The pre-prepared solid powder, pre-prepared liquid solvent, and slurry bulk solvent are mixed and treated to obtain slurry premix; Ball milling treatment: Add photoinitiator and ball milling beads to the slurry premix and perform ball milling treatment to obtain photocurable ceramic core slurry.

2. The method for preparing the photocurable ceramic core slurry according to claim 1, characterized in that, The dispersant is one or more of BYK9076, KOS110, BYK111, KOS163, and BYK180; and / or The photoinitiator is one or both of diphenyl-(2,4,6-trimethylbenzoyl)phosphine and photoinitiator 819; and / or The viscosity of the dispersant is 30-90 MPa·s; and / or The viscosity modifier is selected from a bifunctional resin with a molecular weight range of 220-330; and / or The curing performance modifier is a multifunctional resin with a molecular weight range of 280-470; and / or The main solvent of the slurry is a monofunctional resin with a molecular weight range of 115-215.

3. The method for preparing the photocurable ceramic core slurry according to claim 1, characterized in that, The ceramic matrix powder is selected from one or both of SiO2 particles and Al2O3 particles.

4. The method for preparing the photocurable ceramic core slurry according to claim 3, characterized in that, The particle size of SiO2 particles is 1-100 μm, and the particle size of Al2O3 particles is 50-100 μm.

5. The method for preparing the photocurable ceramic core slurry according to claim 1, characterized in that, The mineralizer is selected from one or both of Al2O3 particles and ZrO2 particles.

6. The method for preparing the photocurable ceramic core slurry according to claim 5, characterized in that, The particle size of Al2O3 particles is 0.1-20 μm, and the particle size of ZrO2 particles is 10-100 nm.

7. The method for preparing the photocurable ceramic core slurry according to claim 1, characterized in that, The photocurable ceramic core slurry comprises 20-30% liquid phase and 60-70% solid phase by volume fraction.

8. The method for preparing the photocurable ceramic core slurry according to claim 1, characterized in that, In the step of preparing the pre-formed solid powder: First, add ceramic matrix powder with large particle size, then add mineralizer with small particle size, and then mix them to obtain pre-made solid powder.

9. The method for preparing the photocurable ceramic core slurry according to claim 1, characterized in that, In the step of preparing the slurry premix: The pre-prepared solid powder is added to the pre-prepared liquid solvent in batches, and then the main solvent of the slurry is added and mechanically mixed to obtain the slurry premix.

10. The method for preparing the photocurable ceramic core slurry according to claim 1, characterized in that, In the ball milling process: The grinding beads are equal-diameter grinding beads; and / or The ball milling speed is 200-600 rpm / min, and the ball milling time is 1.5-3.5 hours.

11. The method for preparing the photocurable ceramic core slurry according to claim 1, characterized in that, In the ball milling process: the mass of the added milling beads is 1 / 3 to 1 / 3 of the total mass of the slurry premix and the photoinitiator.

12. The method for preparing the photocurable ceramic core slurry according to claim 1, characterized in that, In the ball milling process: the mass of the added milling beads is 2 / 3 of the total mass of the slurry premix and the photoinitiator.

13. A photocurable ceramic core slurry, characterized in that, The photocurable ceramic core slurry is prepared by the method for preparing photocurable ceramic core slurry according to any one of claims 1-12.

14. The photocurable ceramic core slurry according to claim 13, characterized in that, The solid content of the photocurable ceramic core slurry is 55-65 vol.

15. The photocurable ceramic core slurry according to claim 13, characterized in that, The viscosity range of the photocurable ceramic core slurry is 2000-6000 MPa·s.

16. A method for preparing a photocurable ceramic core, characterized in that, It includes the following steps: Step 1) Perform photocuring 3D printing on the photocurable ceramic core slurry according to any one of claims 13-15 to obtain a photocurable ceramic core preform; the printing layup speed is 10-20 m / s, and the printing layer thickness is 100-200 micrometers; Step 2) The photocurable ceramic core blank is degreased and sintered to obtain the photocurable ceramic core.

17. A photocurable ceramic core, characterized in that, The photocurable ceramic core is prepared by the photocurable ceramic core preparation method according to claim 16.

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