Surface amorphization functional ceramic powder for high-precision photocuring additive manufacturing as well as preparation method and application of surface amorphization functional ceramic powder

Abstract

The invention belongs to the technical field of functional ceramic materials, and particularly relates to surface amorphization functional ceramic powder for high-precision photocuring additive manufacturing and a preparation method and application of the surface amorphization functional ceramic powder. According to the preparation method, the amorphous silicon-containing coating layer is formed on the surface of the ceramic particle in situ while the ceramic particle is prepared through sol-gel-presintering, the ceramic particle with a core-shell structure is constructed, refractive index gradient matching between ceramic and photosensitive resin is achieved, and therefore the photocuring printing performance is remarkably improved. Besides, the amorphous silica coating structure can effectively induce uniform evolution of a densification path, strengthen grain boundary bonding and inhibit abnormal grain growth in the sintering process, so that the density of the ceramic is remarkably improved, meanwhile, low-temperature sintering is realized, and the adaptation range of a material system and the process compatibility of device design are effectively expanded.

Description

Technical Field

[0001] This application belongs to the field of functional ceramic materials technology, and more specifically, relates to a surface amorphized functional ceramic powder for high-precision photopolymer additive manufacturing, its preparation method and application, belonging to the cross-technical field of advanced ceramic material preparation and 3D printing photopolymer manufacturing. Background Technology

[0002] Functional ceramics, due to their excellent electrical, optical, magnetic, and thermal properties, are widely used in high-tech fields such as sensors, actuators, microelectromechanical systems (MEMS), energy storage devices, and biomedical devices, becoming key materials driving the development of next-generation smart devices. As devices evolve towards miniaturization and high integration, the demand for constructing complex three-dimensional structures is increasing. Traditional two-dimensional forming processes such as dry pressing, isostatic pressing, and tape casting are insufficient to meet the resolution and geometric complexity requirements of microstructure construction. Photopolymerization additive manufacturing technologies (such as DLP and SLA), with their layer-by-layer construction, high resolution, and rapid prototyping capabilities, have become an important direction for manufacturing micro / nano-structured functional ceramics.

[0003] However, the significant difference in optical refractive index between these high-refractive-index ceramics and conventional low-refractive-index photosensitive resins leads to severe scattering effects during UV curing. Scattering reduces light penetration, decreases the effective curing depth, and affects the forming accuracy, density, and shape retention of the components. Furthermore, reducing scattering often necessitates lowering the ceramic content, thus limiting the final performance of the printed structure. Therefore, developing a surface modulation strategy that achieves a gradual matching of the optical refractive index between ceramic particles and photosensitive resin has become a core technical challenge for improving the photopolymerization printing performance of high-refractive-index functional ceramics.

[0004] Traditional optimization methods include particle size optimization, surface coating modification, and resin system control, but these suffer from poor stability, narrow applicability, and complex processes, failing to meet the practical application requirements of high-refractive-index ceramic systems. Among these methods, surface coating modification to reduce the refractive index difference between resin and ceramic materials often involves post-processing the ceramic powder. To form a complete coating layer, a large amount of coating material is typically required. While this method reduces the refractive index difference between the ceramic material and resin to some extent, the excessive amount of coating material significantly degrades the performance of functional ceramic materials, especially piezoelectric ceramics. For example, patent document CN117886607A mixes ceramic powder with a silicon-containing shell material and a binder to form a slurry, then spray-granulates and calcines it to obtain a low-refractive-index composite powder. Although the silicon oxide coating reduces the refractive index of the ceramic material, the high molar percentage of silicon in the shell (17%) inevitably affects the application performance of the ceramic material. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the purpose of this application is to provide a surface amorphized functional ceramic powder for high-precision photopolymer additive manufacturing, its preparation method, and its application, aiming to solve the problems of refractive index mismatch between traditional ceramic powder and photosensitive resin, severe ultraviolet light scattering, insufficient curing depth, poor forming accuracy, and non-dense sintering.

[0006] To achieve the above objectives, in a first aspect, this application provides a method for preparing surface-amorphized functional ceramic powder for high-precision photopolymer additive manufacturing, comprising the following steps: (1) Prepare the precursors of each metal element according to the composition of the target ceramic powder, and mix and dissolve them with solvent and complexing agent to obtain a ceramic precursor solution; the precursors of the metal elements are selected from alkoxides, nitrates, acetates or combinations thereof. (2) Introduce an organosiloxane silicon source into the ceramic precursor solution. The silicon source is a compound that can undergo hydrolysis and condensation reactions to form a Si–O–Si network. Control the amount of silicon source added so that the molar amount of Si atoms accounts for less than or equal to 5% of the total molar amount of the target ceramic powder. Adjust the pH value of the system and stir to allow the silicon source to undergo a hydrolysis reaction to form a stable sol system. (3) The sol system is dried to form a gel precursor; (4) The gel precursor is subjected to pre-sintering heat treatment to form ceramic particles and an amorphous silicon-containing nano-coating layer is formed in situ on its surface. After ball milling, a surface amorphization functional ceramic powder with a core-shell structure is obtained.

[0007] Preferably, the ceramic powder is a high refractive index functional ceramic, selected from Ba(Zr)42O3. x Ti1- x O3, Pb(Zr) x Ti1- x One or more of the following: (K,Na)NbO3, BiFeO3, TiO2, ZrO2, CeO2, ZnO, LaTiO3, and SrTiO3.

[0008] Preferably, the silicon source in step (2) is tetraethyl orthosilicate and / or tetramethoxysilane; the amount of silicon source added is controlled so that the molar amount of Si atoms accounts for 1% to 5% of the total molar amount of the target ceramic powder, and more preferably 1% to 3%.

[0009] Preferably, in step (2), the pH value of the system is adjusted to 3-6 and stirred to cause the silicon source to undergo a hydrolysis reaction, forming a stable sol system.

[0010] Preferably, the pre-sintering temperature is 600–1200°C, and the holding time is 2–5 hours.

[0011] According to another aspect of the present invention, a surface-amorphized functional ceramic powder prepared by the preparation method described above is provided.

[0012] According to another aspect of the present invention, an application of the aforementioned surface-amorphized functional ceramic powder in photocurable additive manufacturing is provided.

[0013] According to another aspect of the present invention, a photocurable additive manufacturing component is provided, which is obtained by photocurable additive manufacturing using the aforementioned surface amorphized functional ceramic powder.

[0014] This invention simultaneously forms an amorphous silicon-containing coating layer on the surface of ceramic particles during sol-gel pre-sintering, constructing ceramic particles with a core-shell structure. This achieves refractive index gradient matching between the ceramic and the photosensitive resin, significantly improving photopolymerization printing performance. Furthermore, this amorphous silicon-oxygen coating structure effectively induces uniform evolution of densification paths during sintering, strengthens grain boundary bonding, and inhibits abnormal grain growth, thereby significantly improving the density of the ceramic. Simultaneously, it enables low-temperature sintering, effectively expanding the applicability of the material system and the process compatibility of device design. Overall, compared with existing technologies, the above-described technical solutions of this application have the following beneficial effects: (1) Significantly reduce light scattering effect: The present invention forms an amorphous coating layer with a refractive index between resin and ceramic on the surface of ceramic particles, which alleviates the sudden change in interface refractive index and effectively reduces the scattering intensity of ultraviolet light in the suspension system, fundamentally improving the light transmission efficiency of the printing system.

[0015] (2) Significantly improve the curing depth and forming accuracy of ultraviolet light: Due to the effective suppression of scattering, ultraviolet light can penetrate deeper into the slurry, thereby achieving a larger curing thickness and higher forming accuracy, which helps to achieve high resolution and high conformity printing of complex structures.

[0016] (3) It helps to improve the solid content and flow properties of ceramic slurry: While improving optical performance, the amorphous coating layer does not significantly affect the dispersion stability between particles. Instead, it plays a role in steric hindrance to a certain extent, inhibiting particle agglomeration, which is beneficial to the preparation of slurry with high solid content and low viscosity.

[0017] (4) Improve the sintering density of ceramics and reduce the sintering temperature: The amorphous coating layer can promote the formation and expansion of the sintering neck during the sintering process. At the same time, some silicon-oxygen components may form a liquid phase sintering mechanism at high temperature, thereby achieving high density sintering at a lower temperature and improving the overall performance of ceramic products.

[0018] (5) It has good adaptability and industrial feasibility: The sol-gel system used in this method has strong compatibility, and the types of silicon sources can be flexibly selected (such as tetraethyl orthosilicate, silane, silica sol, etc.). The processing is mild and easy to integrate with existing preparation processes of various functional ceramic powders (such as piezoelectric, dielectric, photoelectric, thermoelectric, etc.), and has good industrialization prospects.

[0019] (6) The present invention generates an amorphous silicon-containing nano-coating layer in situ while preparing ceramic particles through pre-sintering. The silicon doping content in the ceramic powder is less than 5 mol%, which can minimize its impact on the application performance of functional ceramic powder. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the preparation process of the core-shell structure ceramic powder of the present invention; Figure 2 The image shows the XRD pattern of the core-shell structured ceramic particles prepared in Example 1. Figure 3 Example 1: TEM image of the core-shell structured ceramic particles prepared in Example 1; Figure 4 This is a comparison chart of the printing performance of ceramic powder before and after coating in Comparative Example 1 and Example 1. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0022] This invention provides a method for preparing surface-amorphized functional ceramic powders for high-precision photopolymer additive manufacturing, such as... Figure 1 As shown, it includes the following steps: (1) Prepare the precursors of each metal element according to the composition of the target ceramic powder, and mix and dissolve them with solvent and complexing agent to obtain a ceramic precursor solution; the precursors of the metal elements are selected from one or more of alkoxides, nitrates and acetates. (2) Introduce an organosiloxane silicon source into the ceramic precursor solution. The silicon source is a compound that can undergo hydrolysis and condensation reactions to form a Si–O–Si network. Control the amount of silicon source added so that the molar amount of Si atoms accounts for less than or equal to 5% of the total molar amount of the target ceramic powder. Adjust the pH value of the system and stir to allow the silicon source to undergo a hydrolysis reaction to form a stable sol system. (3) The sol system described in step (2) is dried to form a gel precursor; (4) The gel precursor is subjected to pre-sintering heat treatment to form ceramic particles and an amorphous silicon-containing nano-coating layer is formed in situ on its surface. After ball milling, a surface amorphization functional ceramic powder with a core-shell structure is obtained.

[0023] The ceramic powder described in this invention is a high-refractive-index functional ceramic, selected from Ba(Zr)42O3. x Ti1- x O3, Pb(Zr) x Ti1- x One or more of the following: (K,Na)NbO3, BiFeO3, TiO2, ZrO2, CeO2, ZnO, LaTiO3, SrTiO3, etc.

[0024] In some embodiments, step (1) specifically involves: preparing the precursors of each metal element according to the composition of the target ceramic powder; dissolving inorganic metal salts, such as nitrates or acetates, in anhydrous ethanol or pure water for later use; mixing and stirring the alkoxide with a faster hydrolysis rate and the complexing agent until homogeneous; and then mixing the inorganic metal salt solution and the alkoxide complexing solution to obtain the ceramic precursor solution. The complexing agent is selected from acetylacetone, citric acid, oxalic acid, ethanolamine, etc., and is used to regulate the metal complexation state and inhibit particle agglomeration. The molar ratio of the metal element to the complexing agent in the alkoxide is 1:1–3.

[0025] In some embodiments, the silicon source in step (2) is one or more of silanol salts such as tetraethyl orthosilicate (TEOS) and tetramethoxysilane (TMOS); the amount of silicon source added is controlled so that the molar amount of Si atoms accounts for 1% to 5% of the total molar amount of the target ceramic powder, more preferably 1% to 3%.

[0026] In some embodiments, step (2) adjusts the pH of the system to 3–6 and stirs to allow the silicon source to undergo a hydrolysis reaction, forming a stable sol system. Controlling this pH range to avoid premature precipitation or aggregation of the precursor and excessively rapid hydrolysis of the silicon source to prevent reactions with other metals can be achieved by adding dilute hydrochloric acid, acetic acid, or ammonia to adjust the pH of the system.

[0027] In some embodiments, the pre-sintering temperature is 600–1200°C, and the holding time is 2–5 hours, to achieve the formation of the coating layer without damaging the ceramic powder structure. The pre-sintering temperature needs to ensure the formation of ceramic particles. Experiments have shown that the pre-sintering temperature should not be too high; otherwise, an amorphous coating layer cannot be formed in situ on the surface of the ceramic particles. Consequently, in photopolymer additive manufacturing applications, the gradual matching of the optical refractive index between the ceramic particles and the photosensitive resin cannot be achieved.

[0028] In some embodiments, the thickness of the amorphous silicon nano-coating layer in step (4) is 1 to 10 nanometers.

[0029] In some embodiments, the powder finally prepared by the present invention can also be processed by ball milling, ultrasonic dispersion, spray drying or air classification to obtain photocurable ceramic powder with good dispersibility and uniform particle size.

[0030] The surface-amorphized functional ceramic powder prepared by the above preparation method of the present invention can be used for high-precision photopolymerization additive manufacturing.

[0031] The present invention also provides a photocurable additive manufacturing component, which is obtained by photocurable additive manufacturing using the aforementioned surface amorphized functional ceramic powder.

[0032] The amorphous functional ceramic powder prepared by this invention has an amorphous silicon-containing nano-coating layer with a refractive index between that of the ceramic particles and the photosensitive resin. This effectively reduces the interfacial refractive index difference, achieving refractive index gradient matching during additive manufacturing. This reduces ultraviolet scattering and improves the photocuring depth and forming accuracy. The silicon-containing amorphous nano-coating structure helps control grain growth behavior and enhances intergranular bonding during subsequent sintering, promoting high-density sintering at lower temperatures. This significantly broadens the process window for ceramic forming and sintering, improving the integrity and compatibility of the product structure.

[0033] The preparation of the surface amorphized functional ceramic powder of the present invention is not obtained by directly coating the ceramic powder with post-processing in the traditional method, but by forming an amorphous silicon-containing coating layer on the surface of the ceramic particles in situ while preparing the ceramic particles by sol-gel method. The formation mechanism of this amorphous coating layer may include one or more of the following: (1) the silicon source is not fully crystallized at the pre-sintering temperature; (2) the doping of ceramic elements (such as Ti, Zr, etc.) disturbs the silicon-oxygen network structure to form an amorphous state; (3) the surface of the ceramic particles provides a heterogeneous interface to inhibit the formation of crystal nuclei; (4) the process conditions such as heat treatment rate and oxygen partial pressure limit crystal growth and promote the stability of the amorphous structure.

[0034] This invention relates to a surface-amorphized functional ceramic powder for high-precision photopolymer additive manufacturing and its preparation method, and also to a high-precision photopolymer additive manufacturing method for this high-refractive-index functional ceramic powder, belonging to the interdisciplinary field of functional ceramic materials and 3D printing technology. This method is based on a sol-gel process, introducing an organosilicon source into the ceramic precursor sol. After a pre-sintering stage of heat treatment, a nano-amorphous silicon-oxygen coating layer is generated in situ on the surface of the ceramic particles. The specific formation mechanism mainly includes the incomplete crystallization of the silicon source under low-temperature conditions, the suppression of the crystallization process by dopant ions, the limiting effect of the ceramic particle surface on crystal nucleus formation, and the suppression of crystallization by the local sintering environment. The refractive index of this nano-amorphous layer is between that of the ceramic bulk and the photosensitive resin, effectively reducing the interfacial refractive index difference, thereby significantly suppressing the ultraviolet scattering effect and improving the curing depth, printing accuracy, and structural conformation. Furthermore, this coating structure can induce a uniform and dense sintering mechanism during sintering, promoting grain interface bonding and inhibiting abnormal grain growth, thereby significantly improving the densification degree of ceramics and effectively reducing the sintering temperature. This expands the process window and accommodates more device structure designs and fabrication requirements. This method is applicable to surface control of various high-refractive-index functional ceramic powders, especially piezoelectric, dielectric, optoelectronic, and thermoelectric ceramic systems, providing an effective solution for the high-precision manufacturing of high-performance ceramic devices in high-end fields such as semiconductor devices, 5G communications, and biomedicine.

[0035] The embodiments of the present invention are implemented under the premise of the technical solution of the present invention, and detailed implementation methods and processes are given. However, the protection scope of the present invention is not limited to the following embodiments. The process parameters in the following embodiments that do not specify specific conditions are generally in accordance with conventional conditions.

[0036] The endpoints and any values ​​of the ranges disclosed in this invention are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this invention.

[0037] The process parameters in the following examples, unless otherwise specified, are generally performed under conventional conditions.

[0038] The embodiments of this application are described below with reference to the accompanying drawings.

[0039] Example 1 Ba 0.85 Ca 0.15 (Zr 0.1 Ti 0.9 Preparation of O3@Si core-shell structured powder (1) Preparation of precursor solution: Barium nitrate (Ba(NO3)2), calcium nitrate (Ca(NO3)2), zirconium nitrate (Zr(NO3)2), and isopropyl titanate (Ti(OC3H7)4) were weighed with a molar ratio of Ba:Ca:Zr:Ti = 0.85:0.15:0.1:0.9 as metal precursors. The inorganic metal salts barium nitrate and calcium nitrate were dissolved in pure water. Acetylacetone (acac) was added to isopropyl titanate as a complexing agent to adjust the complexation ratio (titanium ion / acac molar ratio of 1:2). After ultrasonic stirring for 1 hour, the other metal solutions were added and stirred evenly to obtain the precursor solution.

[0040] (2) Introducing a silicon source: Tetraethyl orthosilicate (TEOS) is added dropwise to the above homogeneous solution, and the amount added is controlled so that the molar fraction of Si atoms accounts for 2% of the molar content of the target ceramic powder. Then, ammonia is slowly added dropwise to adjust the pH value to about 4.5, and stirring is continued for 2 hours to form a stable sol system.

[0041] (3) Drying into a gel: The sol was placed in a constant temperature oil bath at 90 °C and allowed to evaporate until a transparent gel block was formed. The resulting gel was further dried at 100 °C for 12 hours to obtain a dry gel precursor.

[0042] (4) Pre-sintering treatment: The dry gel was crushed and placed in a muffle furnace and kept at 900 °C in air atmosphere for 3 hours. During this process, the metal oxide gradually crystallized to form the BCZT ceramic core, while the TEOS hydrolysis product formed a silicide amorphous layer with a thickness of about 2 nm on its surface, thus constructing core-shell structured ceramic particles.

[0043] (5) Powder post-treatment: The pre-sintered powder is ball-milled for 12 hours, and the ball milling method is used to obtain photocurable ceramic powder with uniform particle size distribution and good dispersibility.

[0044] Comparative Example 1 The rest is the same as in Example 1, except that step (2) does not introduce a silicon source, and the surface of the prepared ceramic particles does not contain a siliconized amorphous layer.

[0045] Performance Characterization and Application: The ceramic powder prepared in Example 1 was subjected to XRD analysis, such as... Figure 2 As shown, the ceramic is confirmed to be of the BCZT crystal phase.

[0046] Figure 3 The image shows a TEM image of the core-shell structured ceramic particles prepared in Example 1. The morphology and elemental distribution on the left side indicate that Si elements are aggregated on the particle surface, while the high-resolution image on the right side shows that the ceramic particle surface is coated with a continuous and dense silicide amorphous layer. At the same time, the diffraction of the internal lattice also indicates that the ceramic particle is in the BCZT phase.

[0047] The powders obtained from Comparative Example 1 (without amorphous layer) and Example 1 (with amorphous layer) were respectively dispersed in photosensitive resin 1,6-hexanediol diacrylate (HDDA) (ceramic solid content 50 vol.%), and used for DLP photopolymerization 3D printing. The printed components were tested and analyzed, and the results are as follows: Figure 4 As shown.

[0048] The results showed that at an exposure energy density of 42 mJ / cm² 2 At the same curing process, the solidification depth reached 77 μm with clear forming boundaries. In contrast, the uncoated amorphous powder, under the same curing process, only achieved a solidification depth of approximately 36 μm, with blurred boundaries and noticeable jagged, mis-cured appearance. Tests showed that the UV-cured depth of the ceramic powder in Example 1 was approximately 114% higher than that of the uncoated powder system in Comparative Example 1, the fastest sintering temperature decreased by 40°C, and the sintering density increased from 86.05% to 95.08%. Figure 4 In Comparative Example 1, BCZT represents the ceramic powder printing sample without an amorphous layer, while BCZT@Si represents the ceramic powder printing sample with an amorphous layer in Example 1. This example demonstrates that the refractive index modulation strategy significantly improves the forming performance.

[0049] Comparative Example 2 The other steps are the same as in Example 1, except that in step (2), dilute hydrochloric acid is slowly added to adjust the pH to 2.5. Experiments showed that no gel could be formed.

[0050] Comparative Example 3 The other steps are the same as in Example 1, except that in step (2), dilute hydrochloric acid is slowly added to adjust the pH to 7. Experiments show that an amorphous shell cannot be formed in the end, possibly because the silicon source hydrolyzes too quickly and reacts with other metal elements.

[0051] Example 2 Pb(Zr 0.5 Ti 0.5 Preparation of O3@Si core-shell structured powder (1) Preparation of precursor solution: Weigh appropriate amounts of isopropyl titanate, zirconium nitrate, and lead nitrate (Pb(NO3)2) according to the molar ratio of Pb:Zr:Ti = 1:0.5:0.5. Dissolve zirconium nitrate and lead nitrate in purified water for later use. Add acac to isopropyl titanate to make the molar ratio of titanium ions to acac 1:2, and sonicate for 1 hour. Then add zirconium oxychloric acid and lead nitrate solution and stir evenly to obtain the precursor solution.

[0052] (2) Introducing silicon source and adjusting pH value: Add tetramethoxysilane (TMOS) to the precursor solution, adjust the Si content to 3 mol% of the target ceramic powder, and add dilute hydrochloric acid to control the pH value at 4.5. Continue stirring for 2 hours to form a stable system.

[0053] (3) Gel formation and drying: The sol was evaporated in an oil bath at 90 °C to form a gel, and then dried at 100 °C for 12 hours to obtain a dry gel.

[0054] (4) Pre-sintering treatment: After grinding the dry gel, it is calcined in air at 850 °C for 4 hours to form Pb(Zr) 0.5 Ti 0.5 O3 crystalline particles, with a nano-amorphous silicon oxide layer shell of about 2 nm thick on the surface.

[0055] (5) Powder post-treatment: Ball milling for 12 hours to obtain composite powder with uniform particle size and good flowability.

[0056] (6) Application performance: XRD and TEM characterization showed that the composite powder formed a complete core-shell structure. When the powder (50% by volume) was added to the photosensitive resin HDDA for DLP printing, the printed layer thickness reached 80 μm, and the curing depth was increased by 50% compared with the uncoated sample.

[0057] Example 3 Preparation of (K,Na)NbO3@Si core-shell structured powder (1) Preparation of precursor solution: Potassium nitrate, sodium nitrate and niobium ethoxide (Nb(OC2H5)5) were prepared in a molar ratio of K:Na:Nb = 0.5:0.5:1. Potassium nitrate and sodium nitrate were dissolved in pure water. An appropriate amount of citric acid was added to niobium ethoxide as a complexing agent (the molar ratio of niobium ethoxide to citric acid was about 1:1.5). After ultrasonic stirring for 1 hour, potassium and sodium solution was added and stirred evenly to obtain a stable solution.

[0058] (2) Add silicon source and adjust acid: Add TEOS (Si accounts for 5 mol% of the target ceramic powder) and adjust the pH value to 4.5, and continue stirring to form a uniform sol.

[0059] (3) Gel formation and drying: Evaporate in an oil bath at 90 °C to form a gel, and then dry at 100 °C for 12 hours.

[0060] (4) Calcination treatment: The dry gel was calcined in air at 950 °C for 3 hours to obtain a (K,Na)NbO3 ceramic core with complete crystal structure, and a nano-amorphous silicon-oxygen shell was generated on the surface.

[0061] (5) Powder treatment: ball milling for 12 hours to obtain ceramic composite powder with good dispersibility.

[0062] (6) Performance testing: XRD showed a (K,Na)NbO3 main phase, and TEM confirmed the continuity of the shell. After DLP printing, the pattern edges were clear and the curing thickness was significantly improved, indicating that it is suitable for high-precision ceramic 3D printing.

[0063] Example 4 Preparation of SrTiO3@Si core-shell structured powder (1) Preparation of precursor solution: Isopropyl titanate and strontium nitrate (Sr(NO3)2) are mixed in a ratio of Sr:Ti = 1:1. Strontium nitrate is dissolved in pure water. Acac complexes are added to isopropyl titanate (the molar ratio of titanium ions to aacac is 1:2). After stirring evenly, strontium nitrate solution is added to obtain precursor solution.

[0064] (2) Add TEOS (Si is 5 mol% of the target ceramic powder), add dilute hydrochloric acid dropwise to adjust the pH value to 4.5, and stir the reaction for 2 hours.

[0065] (3) Gel formation and drying: The reaction solution was placed in a 90 ℃ oil bath to evaporate to form a gel block, and then dried at 100 ℃ for 12 hours.

[0066] (4) Calcination: After the dry gel is pulverized, it is calcined at 1000 °C in air atmosphere for 5 hours to obtain SrTiO3 powder with complete crystals and a 5 nm thick nano-amorphous silicon oxide coating on the surface.

[0067] (5) Ball milling for 12 hours to obtain uniform powder suitable for DLP.

[0068] (6) Application characterization: XRD and TEM showed that the successfully constructed core-shell structure was used for photopolymerization printing, and the UV curing depth was increased by 85%, which significantly optimized the printing efficiency and quality.

[0069] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for preparing surface-amorphized functional ceramic powder for high-precision photopolymer additive manufacturing, characterized in that, Includes the following steps: (1) Prepare the precursors of each metal element according to the composition of the target ceramic powder, and mix and dissolve them with solvent and complexing agent to obtain a ceramic precursor solution; the precursors of the metal elements are selected from alkoxides, nitrates, acetates or combinations thereof. (2) Introduce an organosiloxane silicon source into the ceramic precursor solution. The silicon source is a compound that can undergo hydrolysis and condensation reactions to form a Si–O–Si network. Control the amount of silicon source added so that the molar amount of Si atoms accounts for less than or equal to 5% of the total molar amount of the target ceramic powder. Adjust the pH value of the system and stir to allow the silicon source to undergo a hydrolysis reaction to form a stable sol system. (3) The sol system is dried to form a gel precursor; (4) The gel precursor is subjected to pre-sintering heat treatment to form ceramic particles and an amorphous silicon-containing nano-coating layer is formed in situ on its surface. After ball milling, a surface amorphization functional ceramic powder with a core-shell structure is obtained.

2. The preparation method according to claim 1, characterized in that, The ceramic powder is a high-refractive-index functional ceramic, selected from Ba(Zr)42O3. x Ti1- x O3, Pb(Zr) x Ti1- x One or more of the following: (K,Na)NbO3, BiFeO3, TiO2, ZrO2, CeO2, ZnO, LaTiO3, and SrTiO3.

3. The preparation method according to claim 1, characterized in that, The complexing agent in step (1) is selected from acetylacetone, citric acid, oxalic acid and ethanolamine.

4. The preparation method according to claim 1, characterized in that, The silicon source in step (2) is tetraethyl orthosilicate and / or tetramethoxysilane; The amount of silicon source added is controlled so that the molar amount of Si atoms accounts for 1% to 5% of the total molar amount of the target ceramic powder.

5. The preparation method according to claim 1, characterized in that, Step (2) Adjust the pH of the system to 3–6 and stir to allow the silicon source to undergo a hydrolysis reaction to form a stable sol system.

6. The preparation method according to claim 1, characterized in that, The pre-sintering temperature is 600–1200℃, and the holding time is 2–5 hours.

7. The preparation method according to claim 1, characterized in that, The thickness of the amorphous silicon nano-coating layer in step (4) is 1 to 10 nanometers.

8. The surface-amorphized functional ceramic powder prepared by the preparation method according to any one of claims 1 to 7.

9. The application of the surface amorphized functional ceramic powder as described in claim 8 in photocurable additive manufacturing.

10. A photopolymer additive manufacturing component, characterized in that, It is obtained by photocuring additive manufacturing using the surface amorphized functional ceramic powder as described in claim 8.

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