Photocuring 3D printing ceramic material and preparation method thereof

Abstract

The invention relates to a photocuring 3D printing ceramic material and a preparation method thereof, and relates to the technical field of additive manufacturing ceramic materials. The preparation method comprises the following steps: preparing magnetic ceramic slurry containing magnetic ceramic fibers; wherein the magnetic ceramic fiber comprises a ceramic fiber body and a magnetic metal layer coated on the ceramic fiber body; carrying out photocuring 3D printing treatment on the magnetic ceramic slurry to obtain a ceramic biscuit; in the photocuring 3D printing treatment process, at least part of magnetic ceramic fibers in the magnetic ceramic slurry are controlled to be directionally arranged through an external magnetic field, so that the magnetic ceramic fibers in the ceramic biscuit are spatially and stereoscopically distributed; the ceramic biscuit is subjected to degreasing treatment and sintering treatment, and the photocuring 3D printing ceramic material is obtained. The method is mainly used for solving the problem that in an existing photocuring 3D printing ceramic material, due to two-dimensional distribution of ceramic fibers, the bonding performance between printing layers is weak, and the toughening effect is limited.

Description

Technical Field

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

[0002] Ceramic materials, due to their excellent mechanical properties, high-temperature resistance, chemical stability, and corrosion resistance, are widely used in high-end fields such as aerospace, electronic packaging, energy equipment, and medical devices. However, the inherent brittleness of ceramic materials limits their application in applications requiring high strength and thermal shock resistance. Therefore, fiber-reinforced ceramic material technology has become an important research direction to address this problem.

[0003] Conventional fiber-reinforced ceramic material technology often faces the following problems in practical applications: (1) Ceramic fibers are mostly distributed in a two-dimensional plane, resulting in insufficient fiber overlap between printed layers and weak interlayer bonding performance; (2) There is a lack of effective means to control the fiber directionality, and the fiber reinforcement effect cannot be fully utilized; (3) The anisotropy of material properties limits its application in complex environments.

[0004] In recent years, photo-curing 3D printing technology has become an important research direction in ceramic additive manufacturing due to its high precision and ability to form complex structures. However, fiber-reinforced ceramic materials produced using existing photo-curing 3D printing technologies exhibit uneven internal structures, with fibers exhibiting a distinct two-dimensional distribution. This lack of effective control over the three-dimensional distribution of fibers between printed layers results in anisotropic ceramic material properties. Summary of the Invention

[0005] In view of this, the present invention provides a light-cured 3D printing ceramic material and a preparation method thereof, the main purpose of which is to solve the problem in existing light-cured 3D printing ceramic materials that the bonding performance between printed layers is weak due to the two-dimensional distribution of ceramic fibers, resulting in limited toughening effect.

[0006] To achieve the above objectives, the present invention mainly provides the following technical solutions:

[0007] In one aspect, an embodiment of the present invention provides a method for preparing a light-cured 3D printing ceramic material, comprising the following steps:

[0008] The step of preparing a magnetic ceramic slurry comprises preparing a magnetic ceramic slurry; wherein the magnetic ceramic slurry comprises ceramic powder, a reinforcing agent, magnetic ceramic fibers, a liquid solvent, a photoinitiator, and a dispersant; wherein the magnetic ceramic fibers comprise a ceramic fiber body and a magnetic metal layer coated on the ceramic fiber body;

[0009] A light-curing 3D printing step: performing a light-curing 3D printing process on the magnetic ceramic slurry to obtain a ceramic blank; wherein, during the light-curing 3D printing process, an external magnetic field is applied to control the directional arrangement of at least a portion of the magnetic ceramic fibers in the magnetic ceramic slurry so that the magnetic ceramic fibers in the ceramic blank are spatially distributed;

[0010] Degreasing step: degreasing the ceramic green body to obtain a ceramic green body;

[0011] Sintering step: sintering the ceramic body to obtain a light-cured 3D printing ceramic material.

[0012] Preferably, before the step of preparing the ceramic slurry, the method further comprises:

[0013] The steps of preparing magnetic ceramic fibers include: preparing a magnetic metal layer on the surface of a ceramic fiber body to obtain magnetic ceramic fibers;

[0014] Preferably, a magnetron sputtering process is used to prepare a magnetic metal layer on the surface of the ceramic fiber body; further preferably, the magnetron sputtering process is as follows: after evacuating the magnetron sputtering chamber, an inert gas is filled into it to a pressure of 0.1-0.5 Pa, and magnetron sputtering treatment is performed; wherein, the parameters of the magnetron sputtering treatment are controlled as follows: the sputtering power is 300-400W, and the sputtering time is 20-40min; preferably, argon is used as the inert gas.

[0015] Preferably, the ceramic fiber body is a nitride fiber or an oxide fiber; wherein the nitride fiber is a silicon nitride fiber or a boron nitride fiber, and the oxide fiber is an alumina fiber or a quartz fiber; and / or the diameter of the ceramic fiber body is 5-10 μm and the length is 50-200 μm; and / or the composition of the magnetic metal layer includes one or more of iron, nickel, and cobalt; and / or the thickness of the magnetic metal layer is 50-200 nm.

[0016] Preferably, in the step of preparing the magnetic ceramic slurry: in parts by weight, the magnetic ceramic slurry includes: 40-85 parts by weight of ceramic powder, 0.5-10 parts by weight of a reinforcing agent, 5-50 parts by weight of magnetic ceramic fiber, 20-50 parts by weight of a liquid phase solvent, 0.01-0.1 parts by weight of a photoinitiator, and 0.5-5 parts by weight of a dispersant.

[0017] Preferably, the particle size of the ceramic powder is 0.5-5 μm; and / or the ceramic powder is alumina ceramic powder or silicon nitride ceramic powder; and / or the reinforcing agent is selected from one or more of quartz powder, MgO powder, TiO2 powder, ZrO2 powder, and Y2O3 powder; and / or the median particle size of the reinforcing agent is in the range of 50-500 nm; and / or the liquid phase solvent comprises, by volume fraction, 60-90% of photosensitive resin and 10-40% of dilute preferably, the photosensitive resin is one or more of 1,6-hexanediol diacrylate, tripropylene glycol diacrylate, and trimethylolpropane triacrylate; preferably, the diluent is deionized water or silica sol; and / or the photoinitiator is one or more of 819 photoinitiator, 184 photoinitiator, and 369 photoinitiator; and / or the dispersant is one or more of PMA25, BYK9076, and BYK2152.

[0018] Preferably, in the light-curing 3D printing step: the external magnetic field is generated by an electromagnet arranged on a scraper; wherein, the external magnetic field moves with the scraper, thereby producing a directional guiding effect on the magnetic ceramic slurry, and controlling the magnetic ceramic fibers to be distributed in three dimensions in space.

[0019] Preferably, in the light-curing 3D printing step: the light-curing 3D printing equipment used includes: a light-curing 3D printer, a programmable power supply, an electromagnet, and a magnetic shielding material, wherein the scraper of the light-curing 3D printer has a first side portion and a second side portion that are relatively arranged; wherein the direction from the second side portion to the first side portion is the running direction of the scraper; wherein the electromagnet is fixed on the second side portion; a magnetic shielding material is arranged between the electromagnet and the scraper; preferably, the material of the magnetic shielding material is selected from one of permalloy, silicon steel, and ultra-fine crystal alloy; preferably, the programmable power supply is connected to the electromagnet to control the intensity and action time of the external magnetic field during the light-curing 3D printing process.

[0020] Preferably, the parameters of the light-curing 3D printing process are set as follows: the programmable power supply voltage is 0-36V; the intensity of the external magnetic field is 0.1-0.5T; the angle between the magnetic field direction and the printing layer is 0°-90°; the ultraviolet light wavelength range is 355-405nm; the laser power is 200-400mW; the laser scanning speed is 5000-10000mm / s; and the single layer thickness is 25-100μm.

[0021] Preferably, in the degreasing step: in a protective atmosphere, the ceramic green body is heated to 500-700°C and kept warm for 120-360 minutes to perform degreasing treatment, and after cooling with the furnace, a ceramic green body is obtained; preferably, the protective atmosphere is argon or nitrogen; preferably, the ceramic green body is heated to 500-700°C at a heating rate of 0.1-1.0°C / min.

[0022] Preferably, in the sintering step: in a protective atmosphere, the ceramic body is heated to 1200-1700°C and kept warm for 120-360 minutes to perform sintering treatment, and after cooling with the furnace, a ceramic material is obtained; preferably, the protective atmosphere is argon or nitrogen; preferably, the ceramic body is heated to 1200-1700°C at a heating rate of 0.1-1.0°C / min.

[0023] On the other hand, an embodiment of the present invention provides a light-cured 3D printed ceramic material, wherein the light-cured 3D printed ceramic material is prepared by any of the light-cured 3D printed ceramic materials described above; preferably, in the light-cured 3D printed ceramic material, the ceramic fibers are spatially distributed in the matrix; preferably, the light-cured 3D printed ceramic material has a bending strength of 250-350 MPa in the direction of ceramic fiber distribution, which is more than 30% higher than that of traditional isotropic ceramic materials, and a fracture toughness of 4.0-6.0 MPa·m in the vertical plane. 1 / 2 , which is more than 25% higher than traditional isotropic ceramic materials.

[0024] Compared with the prior art, the light-cured 3D printing ceramic material and the preparation method thereof of the present invention have at least the following beneficial effects:

[0025] On the one hand, an embodiment of the present invention provides a method for preparing a photocurable 3D printed ceramic material. When preparing a ceramic slurry, magnetic ceramic fibers are used (specifically, the magnetic ceramic fibers include a ceramic fiber body and a magnetic metal layer coated on the ceramic fiber body). Furthermore, in the photocurable 3D printing step, an external magnetic field is applied to control the directional arrangement of at least part of the magnetic ceramic fibers in the magnetic ceramic slurry so that the magnetic ceramic fibers in the ceramic blank are spatially distributed (not just two-dimensionally distributed on the surface), thereby printing a ceramic blank with a spatial three-dimensional distribution of fibers. Finally, after degreasing and sintering, a photocurable 3D printed ceramic material with a spatial three-dimensional distribution of fibers is obtained. Therefore, the above-mentioned scheme of the embodiment of the present invention overcomes the limitations of the two-dimensional distribution of fibers in traditional ceramic fiber toughening technology, and realizes the multi-directional distribution of fibers inside the ceramic through an external magnetic field, significantly improves the overlap performance between the printed layers, eliminates layered structure printing defects, and improves the fracture toughness and flexural strength of the ceramic material. It can be widely used in aerospace, electronic devices and high-end industrial fields.

[0026] Furthermore, an embodiment of the present invention provides a method for preparing a photocurable 3D printing ceramic material, wherein the magnetic metal layer on the magnetic fiber comprises one or more of iron, nickel, and cobalt; wherein, after the subsequent degreasing and sintering treatment, the magnetic metal layer can act as an interface phase, and when subjected to external force, local plastic yielding occurs near the crack tip, effectively dispersing stress, absorbing crack energy, and inhibiting crack expansion, thereby achieving fiber pull-out toughening.

[0027] Furthermore, an embodiment of the present invention provides a method for preparing a photocurable 3D printing ceramic material. In the photocurable 3D printing step, the programmable power supply and electromagnet process used are highly flexible and have a wide range of application scenarios. The intensity and magnetization period of the external magnetic field can be adjusted according to different printing materials and printing environments to improve printing efficiency.

[0028] Furthermore, an embodiment of the present invention provides a method for preparing a photocurable 3D printing ceramic material, in which an inert gas such as argon or nitrogen is used in the degreasing and sintering steps to prevent the fiber from being oxidized, thereby improving the chemical stability of the magnetic metal layer and the ceramic fiber body.

[0029] 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 with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 1 is a schematic diagram of a preparation process of a method for preparing a light-cured 3D printing ceramic material provided by an embodiment of the present invention;

[0031] Figure 2 This is a schematic diagram of applying an external magnetic field to assist printing in the light-curing 3D printing step provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0032] To further illustrate the technical means and effects employed by the present invention to achieve its intended objectives, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention is provided in conjunction with the accompanying drawings and preferred embodiments. In the following description, different references to "one embodiment" or "embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics of one or more embodiments may be combined in any suitable manner.

[0033] By applying an external magnetic field to magnetic ceramic fibers, their directional alignment during printing can be achieved, effectively improving material properties. However, the process of introducing magnetic fields into the photocuring 3D printing process to achieve three-dimensional distribution of ceramic fibers is not yet mature. It is difficult to precisely control the spatial distribution of fibers through magnetic fields, resulting in a predominantly two-dimensional distribution of fibers within the printed layer, and weak interlayer bonding.

[0034] The present invention achieves a three-dimensional distribution of fibers within the printed layer by coating a magnetic metal layer on the surface of a ceramic fiber body and combining it with a magnetic field guide device in a light-curing 3D printing device. This improves the interlayer bonding strength and fracture toughness of the ceramic material, providing a new approach for the preparation of high-performance ceramic materials. The technical solutions of the present invention are as follows:

[0035] On the one hand, the embodiment of the present invention provides a method for preparing a light-cured 3D printing ceramic material, such as Figure 1 As shown, it includes the following steps:

[0036] The steps of preparing magnetic ceramic fiber are as follows: a magnetic metal layer is prepared on the surface of the ceramic fiber body to obtain magnetic ceramic fiber.

[0037] Preferably, a magnetron sputtering process is used to prepare a magnetic metal layer on the surface of the ceramic fiber body; preferably, the parameters of the magnetron sputtering process are controlled as follows: sputtering power is 300-400W, argon pressure is 0.1-0.5Pa, and sputtering time is 20-40min.

[0038] Preferably, the ceramic fiber body is a nitride fiber or an oxide fiber. The nitride fiber is a silicon nitride fiber or a boron nitride fiber, and the oxide fiber is an aluminum oxide fiber or a quartz fiber. The ceramic fiber body has a diameter of 5-10 μm and a length of 50-200 μm. The magnetic metal layer comprises one or more of iron, nickel, and cobalt. The thickness of the magnetic metal layer is 50-200 nm.

[0039] The steps of preparing magnetic ceramic slurry are as follows: preparing magnetic ceramic slurry; wherein, the magnetic ceramic slurry includes ceramic powder, a reinforcing agent, magnetic ceramic fiber, a liquid solvent, a photoinitiator and a dispersant; wherein, the magnetic ceramic fiber includes a ceramic fiber body and a magnetic metal layer coated on the ceramic fiber body.

[0040] Preferably, in the step of preparing the magnetic ceramic slurry: in parts by weight, the magnetic ceramic slurry includes: 40-85 parts by weight of ceramic powder, 0.5-10 parts by weight of a reinforcing agent, 5-50 parts by weight of magnetic ceramic fiber, 20-50 parts by weight of a liquid phase solvent, 0.01-0.1 parts by weight of a photoinitiator, and 0.5-5 parts by weight of a dispersant.

[0041] Preferably, the ceramic powder has a particle size of 0.5-5 μm. The ceramic powder is alumina ceramic powder or silica ceramic powder. The strengthening agent is selected from one or more of quartz powder, MgO powder, TiO2 powder, ZrO2 powder, and Y2O3 powder. The median particle size of the strengthening agent is 50-500 nm. The liquid solvent comprises, by volume, 60-90% photosensitive resin and 10-40% diluent. The photosensitive resin is selected from one or more of 1,6-hexanediol diacrylate, tripropylene glycol diacrylate, and trimethylolpropane triacrylate. Preferably, the diluent is deionized water or silica sol. The photoinitiator is selected from one or more of 819 photoinitiator, 184 photoinitiator, and 369 photoinitiator; and / or the dispersant is selected from one or more of PMA25, BYK9076, and BYK2152.

[0042] The step of photocuring 3D printing is as follows: the magnetic ceramic slurry is subjected to photocuring 3D printing to obtain a ceramic blank; wherein, during the photocuring 3D printing process, at least part of the magnetic ceramic fibers in the magnetic ceramic slurry are controlled to be oriented by an external magnetic field, so that the magnetic ceramic fibers in the ceramic blank are spatially distributed.

[0043] Preferably, if Figure 2 As shown, in the light-curing 3D printing step: an external magnetic field is generated by an electromagnet 4 disposed on a scraper 2; wherein the external magnetic field moves with the scraper 2, providing a directional guidance effect on the magnetic ceramic slurry 1, controlling the vertical alignment of at least a portion of the magnetic ceramic fibers 11; preferably, the scraper 2 has a first side portion (front portion) and a second side portion (rear portion) disposed opposite each other; wherein the direction from the second side portion to the first side portion is the direction of movement of the scraper; wherein the electromagnet 4 is fixed to the second side portion. Preferably, a magnetic shielding material 3 is disposed between the electromagnet 4 and the scraper.

[0044] Preferably, the stereolithography 3D printing equipment used includes: a stereolithography printer, a programmable power supply, an electromagnet, and a magnetic shielding material. Preferably, the magnetic shielding material is selected from one of permalloy, silicon steel sheet, and ultrafine-grained alloy. The programmable power supply is connected to the electromagnet to control the intensity and duration of the applied magnetic field during the stereolithography 3D printing process.

[0045] Preferably, the parameters of the light-curing 3D printing process are set as follows:

[0046] The programmable power supply voltage is 0-36V (preferably 4-36V); the intensity of the external magnetic field is 0.1-0.5T, and the angle between the magnetic field direction and the printing layer is 0°-90°; the ultraviolet light wavelength range is 355-405nm; the laser power is 200-400mW; the laser scanning speed is 5000-10000mm / s; and the single layer thickness is 25-100μm.

[0047] Degreasing step: Degreasing the ceramic green body to obtain a ceramic green body. Preferably, in this step, the ceramic green body is heated to 500-700°C in a protective atmosphere and held at this temperature for 120-360 minutes for degreasing. After cooling, the ceramic green body is obtained. Preferably, the protective atmosphere is argon or nitrogen. Preferably, the ceramic green body is heated to 500-700°C at a heating rate of 0.1-1.0°C / min.

[0048] Sintering step: The ceramic body is sintered to obtain a ceramic material. Preferably, in this step, the ceramic body is heated to 1200-1700°C in a protective atmosphere and held at this temperature for 120-360 minutes to perform the sintering process. After cooling, a light-cured 3D printing ceramic material is obtained. Preferably, the protective atmosphere is argon or nitrogen. Preferably, the ceramic body is heated to 1200-1700°C at a heating rate of 0.1-1.0°C / min.

[0049] In summary, (1) the above-mentioned method of the present invention overcomes the limitation of two-dimensional fiber distribution in traditional ceramic fiber toughening methods by auxiliary guidance of external magnetic field equipment, realizes vertical overlap of fibers between printed layers, and effectively improves the interlayer bonding performance; (2) The photocurable 3D printed ceramic material prepared by the method of the present invention has a significant toughening effect. The magnetic material on the ceramic fiber plays the role of an interface phase after sintering, which can effectively disperse stress, absorb crack energy and inhibit crack expansion, and realize fiber pull-out toughening; (3) The programmable power supply and electromagnet process used in the method of the present invention are highly flexible and have a wide range of application scenarios. The intensity and magnetization period of the external magnetic field can be adjusted according to different printing materials and printing environments to improve printing efficiency.

[0050] The present invention is further described below by means of specific examples:

[0051] Example 1

[0052] This embodiment prepares a light-cured 3D printing ceramic material, which mainly includes the following steps:

[0053] Preparation of magnetic ceramic fiber: A magnetic metal layer is formed on the surface of a ceramic fiber body using a magnetron sputtering process to obtain a magnetic ceramic fiber. The parameters of the magnetron sputtering process are controlled as follows: the sputtering power is 400W, the magnetron sputtering chamber is evacuated, and then filled with argon gas at a pressure of 0.3Pa and a sputtering time of 40 minutes. The ceramic fiber body is made of aluminum oxide ceramic fiber (alumina ceramic fiber) with a diameter of 8μm and a length of 150μm; the thickness of the magnetic metal layer is 100nm, specifically a nickel-based magnetic metal layer.

[0054] The magnetic ceramic slurry is prepared by weighing 50 parts by weight of alumina ceramic powder, 8 parts by weight of magnetic ceramic fiber, 2 parts by weight of magnesium oxide reinforcement, 21 parts by weight of photosensitive resin, 7.5 parts by weight of diluent, 0.5 parts by weight of 819 photoinitiator, and 1 part by weight of BYK9076 dispersant. The volume fraction of the photosensitive resin in the liquid solvent is 70%, and the volume fraction of the diluent in the liquid solvent is 30%. The weighed materials are added to a planetary ball mill at 300 rpm for 360 minutes to produce a uniform magnetic ceramic slurry with a viscosity of 900 mPa·s. The alumina ceramic powder is spherical with a particle size of 1 μm, the reinforcement has a median particle size of 500 nm, and the photosensitive resin is trimethylolpropane triacrylate.

[0055] Photocuring 3D printing step: performing photocuring 3D printing on the magnetic ceramic slurry to obtain a ceramic blank; wherein the specific steps are as follows:

[0056] Design a ceramic 3D model, slice the model, and export an STL file that can be recognized by a 3D printer. Add the magnetic ceramic slurry to the trough of a UV-curing 3D printer with a wavelength of 355nm. Set the printing parameters as follows:

[0057] The programmable power supply voltage is 24V; the laser power is 300mW; the laser scanning speed is 8000mm / s; the single layer printing thickness is 50μm; the external magnetic field strength is 0.3T; and the magnetic field direction is perpendicular to the printing platform (Z direction). Figure 2 As shown, during the printing process, the electromagnet 4 is fixed to the rear of the scraper 2 and generates a stable magnetic field as the scraper 2 moves, which orients the magnetic ceramic fibers 11. Some fibers are perpendicular to the printed layer, forming a three-dimensional distribution structure.

[0058] Degreasing treatment step: Place the ceramic blank in a muffle furnace for degreasing treatment. The specific process is: in a protective atmosphere, heat the ceramic blank to 600°C at a heating rate of 0.3°C / min, and keep it at this temperature for 180 minutes for degreasing treatment. After cooling, a ceramic body is obtained.

[0059] Sintering treatment steps: Place the ceramic body in a high-temperature sintering furnace for sintering treatment. The sintering process is as follows: In a protective atmosphere, heat the ceramic body to 1550°C at a heating rate of 0.3°C / min and keep it warm for 180 minutes for sintering treatment. Then cool it naturally to room temperature to obtain a light-cured 3D printing ceramic material with uniformly distributed fibers.

[0060] In the light-cured 3D printing ceramic material prepared in this embodiment, the fibers are spatially distributed inside the ceramic, there are fiber overlaps between the ceramic printing layers, and the degree of sintering inside the ceramic is high.

[0061] Example 2

[0062] This embodiment prepares a light-cured 3D printing ceramic material, which mainly includes the following steps:

[0063] Preparation of magnetic ceramic fibers: A magnetic metal layer is deposited on the surface of a ceramic fiber body using a magnetron sputtering process to produce the magnetic ceramic fiber. The magnetron sputtering process parameters are controlled as follows: sputtering power of 400W, argon gas is filled into the magnetron sputtering chamber after evacuation, pressure is 0.3Pa, and sputtering time is 40 minutes. The ceramic fiber body is made of alumina fibers with a diameter of 10μm and a length of 200μm. The magnetic metal layer is 150nm thick and is specifically an iron-nickel alloy magnetic layer.

[0064] The magnetic ceramic slurry was prepared by weighing 50 parts by weight of alumina powder, 8 parts by weight of magnetic ceramic fiber, 2 parts by weight of magnesium oxide reinforcement, 21 parts by weight of photosensitive resin, 7.5 parts by weight of diluent, 0.5 parts by weight of 819 photoinitiator, and 1 part by weight of BYK9076 dispersant. The volume fraction of the photosensitive resin in the liquid solvent was 70%, and the volume fraction of the diluent was 30%. The weighed materials were added to a planetary ball mill at 300 rpm for 240 minutes to produce a uniform magnetic ceramic slurry with a viscosity of 950 mPa·s. The alumina ceramic powder was spherical with a particle size of 2 μm, and the photosensitive resin was a mixture of trimethylolpropane triacrylate and tripropylene glycol diacrylate in a volume ratio of 2:1. The reinforcement had a median particle size of 500 nm.

[0065] Photocuring 3D printing step: performing photocuring 3D printing on the magnetic ceramic slurry to obtain a ceramic blank; wherein the specific steps are as follows:

[0066] Design a ceramic 3D model, slice the model, and export an STL file that can be recognized by a 3D printer. Add the magnetic ceramic slurry to the trough of a UV-curing 3D printer with a wavelength of 355nm. Set the printing parameters as follows:

[0067] The programmable power supply voltage is 24V; the laser power is 350mW; the scanning speed is 8000mm / s; the single layer printing thickness is 100μm; the external magnetic field strength is 0.3T; the magnetic field direction is at a 45° angle to the printing platform. Figure 2 As shown, during the printing process, the electromagnet 4 is fixed to the rear of the scraper 2 and generates a stable magnetic field as the scraper 2 moves, which orients the magnetic ceramic fibers 11, with some fibers tilted toward the printed layer.

[0068] Degreasing treatment step: Place the ceramic blank in a muffle furnace for degreasing treatment. The specific process is: in a protective atmosphere, heat the ceramic blank to 600°C at a heating rate of 0.3°C / min, and keep it at this temperature for 240 minutes for degreasing treatment. After cooling, a ceramic body is obtained.

[0069] Sintering treatment steps: Place the ceramic body in a high-temperature sintering furnace for sintering treatment. The sintering process is as follows: In a protective atmosphere, heat the ceramic body to 1600°C at a heating rate of 0.3°C / min and keep it warm for 240 minutes to perform sintering treatment. Then naturally cool it to room temperature to obtain a light-cured 3D printing ceramic material.

[0070] In the light-cured 3D printing ceramic material prepared in this embodiment, the fibers are spatially distributed inside the ceramic, there are fiber overlaps between the ceramic printing layers, and the degree of sintering inside the ceramic is high.

[0071] Example 3

[0072] This embodiment prepares a light-cured 3D printing ceramic material, which mainly includes the following steps:

[0073] Preparation of magnetic ceramic fibers: A magnetic metal layer is deposited on the surface of a ceramic fiber body using a magnetron sputtering process to produce the magnetic ceramic fiber. The magnetron sputtering process parameters are controlled as follows: sputtering power of 400W, argon gas is filled into the magnetron sputtering chamber after evacuation, pressure is 0.3Pa, and sputtering time is 40 minutes. The ceramic fiber body is made of alumina fibers with a diameter of 10μm and a length of 200μm. The magnetic metal layer is 150nm thick and is specifically an iron-nickel alloy magnetic layer.

[0074] The magnetic ceramic slurry was prepared by weighing 50 parts by weight of alumina powder, 8 parts by weight of magnetic ceramic fiber, 2 parts by weight of magnesium oxide as a reinforcing agent, 21 parts by weight of a photosensitive resin, 7.5 parts by weight of a diluent, 0.5 parts by weight of an 819 photoinitiator, and 1 part by weight of a dispersant, BYK9076. The volume fraction of the photosensitive resin in the liquid solvent was 70%, and the volume fraction of the diluent was 30%. The weighed materials were added to a planetary ball mill at 300 rpm for 240 minutes to produce a uniform magnetic ceramic slurry with a viscosity of 950 mPa·s. The alumina powder was spherical with a particle size of 2 μm, and the photosensitive resin was a mixture of trimethylolpropane triacrylate and tripropylene glycol diacrylate in a volume ratio of 2:1. The median particle size of the reinforcing agent was 500 nm.

[0075] Photocuring 3D printing step: performing photocuring 3D printing on the magnetic ceramic slurry to obtain a ceramic blank; wherein the specific steps are as follows:

[0076] Design a ceramic 3D model, slice the model, and export an STL file that can be recognized by a 3D printer. Add the magnetic ceramic slurry to the trough of a UV-curing 3D printer with a wavelength of 355nm. Set the printing parameters as follows:

[0077] The programmable power supply voltage is 24V; the laser power is 350mW; the scanning speed is 8000mm / s; the single layer printing thickness is 100μm; the external magnetic field strength is 0.3T; the magnetic field direction is at a 45° angle to the printing platform. Figure 2 As shown, during the printing process, the electromagnet 4 is fixed to the rear of the scraper 2 and generates a stable magnetic field as the scraper 2 moves, which orients the magnetic ceramic fibers 11, with some fibers tilted toward the printed layer.

[0078] Degreasing treatment step: Place the ceramic blank in a muffle furnace for degreasing treatment. The specific process is: in a protective atmosphere, heat the ceramic blank to 600°C at a heating rate of 0.3°C / min, and keep it at this temperature for 240 minutes for degreasing treatment. After cooling, a ceramic body is obtained.

[0079] Sintering treatment steps: Place the ceramic body in a high-temperature sintering furnace for sintering treatment. The sintering process is as follows: In a protective atmosphere, heat the ceramic body to 1550°C at a heating rate of 0.3°C / min and keep it warm for 240 minutes for sintering treatment. Then naturally cool it to room temperature to obtain a light-cured 3D printing ceramic material.

[0080] In the light-cured 3D printing ceramic material prepared in this embodiment, the fibers are spatially distributed inside the ceramic, there are fiber overlaps between the ceramic printing layers, and the degree of sintering inside the ceramic is high.

[0081] Comparative Example 1

[0082] Comparative Example 1 prepares a photocurable 3D printing ceramic material. Compared with Example 1, Comparative Example 1 does not apply an external magnetic field during the photocurable 3D printing step.

[0083] Other steps and parameters are the same as those in Example 1.

[0084] The light-cured 3D printing ceramic material prepared in Comparative Example 1 has the following structural characteristics: the fibers are distributed in a planar manner inside the ceramic, there is no fiber overlap between the ceramic printing layers, and the sintering degree is high.

[0085] Comparative Example 2

[0086] Comparative Example 2 prepares a photocurable 3D printing ceramic material. Compared with Example 1, Comparative Example 2 does not set the step of preparing magnetic ceramic fibers. Instead, a silicon oxide ceramic fiber body (without a magnetic metal coating on the surface) is directly used to replace the magnetic ceramic fibers in Example 1 to prepare the ceramic slurry.

[0087] Other steps and parameters are the same as those in Example 1.

[0088] The light-cured 3D printing ceramic material prepared in Comparative Example 2 has the following structural characteristics: the fibers are distributed in a planar manner inside the ceramic, there is no fiber overlap between the ceramic printing layers, and the sintering degree is high.

[0089] Comparative Example 3

[0090] Comparative Example 3: A light-cured 3D printing ceramic material was prepared. Compared with Example 1, the degreasing and sintering steps of Comparative Example 3 were as follows:

[0091] Degreasing treatment: The ceramic green body is placed in a muffle furnace for degreasing treatment. The specific process is as follows: in a protective atmosphere, the ceramic green body is heated to 600°C at a heating rate of 2.0°C / min, and kept at this temperature for 2 hours for degreasing treatment. After cooling, the ceramic green body is obtained.

[0092] Sintering treatment: In a protective atmosphere, the ceramic body was heated to 1550°C at a heating rate of 2.0°C / min and kept at this temperature for 180 minutes for sintering treatment. The body was then naturally cooled to room temperature to obtain a light-cured 3D printing ceramic material.

[0093] Other steps and parameters are the same as those in Example 1.

[0094] The light-cured 3D printing ceramic material prepared in Comparative Example 3 has the following structural characteristics: the fibers are spatially distributed inside the ceramic, there are fiber overlaps between the ceramic printing layers, but there are many pores inside the ceramic, the ceramic particles are small in size, and the degree of sintering is low.

[0095] The mechanical properties of the light-cured 3D printing ceramic materials prepared in Examples 1-2 and Comparative Examples 1-3 are shown in Table 1:

[0096] Table 1

[0097] Bending strength fracture toughness Example 1 316MPa <![CDATA[5.5MPa·m 1 / 2 ]]> Example 2 289MPa <![CDATA[5.1MPa·m 1 / 2 ]]> Example 3 251MPa <![CDATA[4.8MPa·m 1 / 2 ]]> Comparative Example 1 197MPa <![CDATA[3.8MPa·m 1 / 2 ]]> Comparative Example 2 209MPa <![CDATA[4.2MPa·m 1 / 2 ]]> Comparative Example 3 152MPa <![CDATA[3.3MPa·m 1 / 2 ]]>

[0098] It can be seen from the above examples, comparative examples and Table 1 that:

[0099] (1) Compared with Comparative Example 1 without applying a magnetic field and Comparative Example 2 without using magnetic ceramic fibers, the samples prepared in Examples 1-3 have higher flexural strength and fracture toughness under the synergistic effect of the applied magnetic field and the magnetic ceramic fibers.

[0100] (2) The sintering temperature also has a great influence on the performance of the sample. The flexural strength and fracture toughness of Example 2 sintered at 1550°C are significantly lower than those of Example 1 sintered at 1600°C. Therefore, the optimal sintering temperature is 1600°C.

[0101] (3) The heating rate during the degreasing and sintering processes also significantly affects sample performance. In Comparative Example 3, due to the relatively fast heating rate, the degreasing process was inadequate, and resin easily remained inside the sample. Further increasing the temperature to enter the sintering stage caused the accumulated stress inside the sample to induce cracks, destroying the sample structure. Consequently, the flexural strength and fracture toughness were significantly lower than those of Example 1, which had a slower heating rate.

[0102] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Any simple modifications, equivalent changes and modifications made to the above embodiment based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A method for preparing a light-cured 3D printing ceramic material, characterized in that: It includes the following steps: The step of preparing a magnetic ceramic slurry comprises preparing a magnetic ceramic slurry; wherein the magnetic ceramic slurry comprises ceramic powder, a reinforcing agent, magnetic ceramic fibers, a liquid solvent, a photoinitiator, and a dispersant; wherein the magnetic ceramic fibers comprise a ceramic fiber body and a magnetic metal layer coated on the ceramic fiber body; A light-curing 3D printing step: performing a light-curing 3D printing process on the magnetic ceramic slurry to obtain a ceramic blank; wherein, during the light-curing 3D printing process, an external magnetic field is applied to control the directional arrangement of at least a portion of the magnetic ceramic fibers in the magnetic ceramic slurry so that the magnetic ceramic fibers in the ceramic blank are spatially distributed; Degreasing step: degreasing the ceramic green body to obtain a ceramic green body; Sintering step: sintering the ceramic body to obtain a light-cured 3D printing ceramic material.

2. The method for preparing a light-cured 3D printing ceramic material according to claim 1, wherein: Before the step of preparing the ceramic slurry, the method further comprises: The steps of preparing magnetic ceramic fibers include: preparing a magnetic metal layer on the surface of a ceramic fiber body to obtain magnetic ceramic fibers; Preferably, a magnetron sputtering process is used to prepare a magnetic metal layer on the surface of the ceramic fiber body; further preferably, the magnetron sputtering process is as follows: after evacuating the magnetron sputtering chamber, an inert gas is filled into it to a pressure of 0.1-0.5 Pa, and magnetron sputtering treatment is performed; wherein, the parameters of the magnetron sputtering treatment are controlled as follows: the sputtering power is 300-400W, and the sputtering time is 20-40min; preferably, argon is used as the inert gas.

3. The method for preparing a light-cured 3D printing ceramic material according to claim 1 or 2, wherein: The ceramic fiber body is nitride fiber or oxide fiber; wherein the nitride fiber is silicon nitride fiber or boron nitride fiber, and the oxide fiber is alumina fiber or quartz fiber; and / or The ceramic fiber body has a diameter of 5-10 μm and a length of 50-200 μm; and / or The composition of the magnetic metal layer includes one or more of iron, nickel and cobalt; and / or The thickness of the magnetic metal layer is 50-200 nm.

4. The method for preparing a light-cured 3D printing ceramic material according to any one of claims 1 to 3, characterized in that: In the step of preparing the magnetic ceramic slurry: in parts by weight, the magnetic ceramic slurry includes: 40-85 parts by weight of ceramic powder, 0.5-10 parts by weight of a reinforcing agent, 5-50 parts by weight of magnetic ceramic fiber, 20-50 parts by weight of a liquid phase solvent, 0.01-1 parts by weight of a photoinitiator, and 0.5-5 parts by weight of a dispersant.

5. The method for preparing a light-cured 3D printing ceramic material according to any one of claims 1 to 4, characterized in that: The particle size of the ceramic powder is 0.5-5 μm; and / or The ceramic powder is alumina ceramic powder or silicon nitride ceramic powder; and / or The strengthening agent is selected from one or more of quartz powder, MgO powder, TiO2 powder, ZrO2 powder, and Y2O3 powder; and / or The median particle size of the reinforcing agent is in the range of 50-500 nm; and / or In terms of volume fraction, the liquid phase solvent comprises 60-90% of a photosensitive resin and 10-40% of a diluent; preferably, the photosensitive resin is one or more of 1,6-hexanediol diacrylate, tripropylene glycol diacrylate, and trimethylolpropane triacrylate; preferably, the diluent is deionized water or silica sol; and / or The photoinitiator is selected from one or more of 819 photoinitiator, 184 photoinitiator, and 369 photoinitiator; and / or The dispersant is selected from one or more of PMA25, BYK9076, and BYK2152.

6. The method for preparing a light-cured 3D printing ceramic material according to any one of claims 1 to 5, characterized in that: In the light-curing 3D printing step: The external magnetic field is generated by an electromagnet arranged on the scraper; wherein, the external magnetic field moves with the scraper, produces a directional guiding effect on the magnetic ceramic slurry, and controls the magnetic ceramic fibers to be distributed in three dimensions.

7. The method for preparing a light-cured 3D printing ceramic material according to claims 1-6, characterized in that: In the light-curing 3D printing step: The used light-curing 3D printing device includes: a light-curing 3D printer, a programmable power supply, an electromagnet, and a magnetic shielding material, wherein the scraper of the light-curing 3D printer has a first side portion and a second side portion that are arranged opposite to each other; wherein the direction from the second side portion to the first side portion is the running direction of the scraper; wherein the electromagnet is fixed to the second side portion; and the magnetic shielding material is provided between the electromagnet and the scraper; Preferably, the material of the magnetic shielding material is selected from one of Permalloy, silicon steel, and ultra-fine crystal alloy; Preferably, the programmable power supply is connected to the electromagnet to control the intensity and action time of the external magnetic field during the light-curing 3D printing process.

8. The method for preparing a light-cured 3D printing ceramic material according to any one of claims 1 to 7, characterized in that: The parameters of the light-curing 3D printing process are set as follows: The programmable power supply voltage is 0-36V; the strength of the external magnetic field is 0.1-0.5T; the angle between the magnetic field direction and the printing layer is 0°-90°; the ultraviolet light wavelength range is 355-405nm; the laser power is 200-400mW; the laser scanning speed is 5000-10000mm / s; and the single layer thickness is 25-100μm.

9. The method for preparing a light-cured 3D printing ceramic material according to any one of claims 1 to 8, characterized in that: In the degreasing step: In a protective atmosphere, the ceramic green body is heated to 500-700°C and kept at this temperature for 120-360 minutes to perform degreasing treatment, and then cooled in the furnace to obtain a ceramic green body; Preferably, the protective atmosphere is argon or nitrogen; Preferably, the ceramic green body is heated to 500-700° C. at a heating rate of 0.1-1.0° C. / min.

10. The method for preparing a light-cured 3D printing ceramic material according to any one of claims 1 to 9, characterized in that: In the sintering step: In a protective atmosphere, the ceramic body is heated to 1200-1700°C and kept at this temperature for 120-360 minutes to perform a sintering process, and then cooled in the furnace to obtain a ceramic material; Preferably, the protective atmosphere is argon or nitrogen; Preferably, the ceramic body is heated to 1200-1700° C. at a heating rate of 0.1-1.0° C. / min.

11. A light-cured 3D printing ceramic material, characterized in that: The light-curing 3D printing ceramic material is prepared from the light-curing 3D printing ceramic material according to any one of claims 1 to 10; Preferably, in the light-cured 3D printing ceramic material, the ceramic fibers are spatially distributed in the matrix; Preferably, the bending strength of the light-cured 3D printed ceramic material in the direction of ceramic fiber distribution is 250-350 MPa, and the fracture toughness in the vertical plane is 4.0-6.0 MPa·m 1 / 2 .

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