A ceramic structure and a method for producing the same

Abstract

The present application relates to the technical field of ceramic material, and particularly relates to a ceramic structure and a preparation method thereof.The preparation method of the ceramic structure provided by the present application comprises the following steps: S1, mixing a multi-anchor point dispersant, an oligo-anchor point additive and a solvent to obtain a composite dispersant solution; S2, dispersing and treating ceramic powder, a sintering additive and the composite dispersant solution to obtain a dispersed material; S3, dispersing and treating a solution containing a binder and the dispersed material to obtain a ceramic slurry; S4, sequentially performing forming, drying and sintering on the ceramic slurry to obtain the ceramic structure; the multi-anchor point dispersant comprises a compound with the number of adsorption groups in a single molecule being greater than or equal to 11, and the oligo-anchor point additive comprises a compound with the number of adsorption groups in a single molecule being less than or equal to 10; the adsorption groups comprise at least one of a hydroxyl group, an amino group, a carboxyl group, a carbonyl group and an ether oxygen bond.The method can improve the dispersing effect while ensuring effective adsorption of the binder, so that the material has uniform texture and the performance can be effectively exerted.

Description

Technical Field

[0001] This invention relates to the field of ceramic materials technology, and more specifically, to a ceramic structure and its preparation method. Background Technology

[0002] Due to their unique atomic bonding methods (mainly ionic and covalent bonds) and controllable microstructure, ceramics exhibit excellent comprehensive properties such as thermal stability, electrical insulation or specific functional electrical properties, high hardness, corrosion resistance and chemical inertness, enabling ceramic structures to be used more and more widely in many cutting-edge fields such as aerospace, energy, electronics, biomedicine, defense and advanced manufacturing.

[0003] Agglomerates are secondary particles formed when multiple primary particles adhere together during ceramic powder processing due to van der Waals forces, electrostatic interactions, or capillary forces. If these agglomerates are not effectively dispersed and are incorporated into the final ceramic green body or sintered body, they will introduce various defects into the material. Furthermore, volume changes occur during the drying process of ceramic slurry, and defects are also introduced when internal stress approaches the binder's adhesion threshold, thus significantly degrading its thermal, mechanical, and optical properties.

[0004] Thermally, agglomerates have low density and high porosity, forming thermally resistive interfaces. Phonons scatter when passing through them, leading to a decrease in thermal conductivity. Mechanically, agglomerates are often accompanied by micropores, microcracks, or coarse grains, becoming stress concentration sources under external loads. This promotes crack initiation and propagation, significantly reducing flexural strength, fracture toughness, and fatigue life. They also cause uneven density and abnormal sintering, not only reducing overall density but also potentially leading to warping, deformation, or even cracking. Furthermore, they result in lower local hardness, weakening overall hardness and wear resistance, especially noticeable in structural ceramics (such as alumina and silicon nitride). Optically, for transparent or optical ceramics, agglomerates cause porosity, second phase, or grain boundary anomalies that strongly scatter visible or infrared light, leading to enhanced light scattering and decreased transmittance. Density or compositional fluctuations in agglomerated regions result in local refractive index inhomogeneity, causing optical path distortion and affecting imaging quality or laser output performance. For fluorescent and laser ceramics, agglomeration can also lead to uneven distribution of activators, forming concentration quenching regions or non-radiative recombination centers, reducing quantum efficiency and gain coefficient, and decreasing luminous efficiency.

[0005] Aggregates introduce structural inhomogeneities that can disrupt the performance consistency of ceramics at multiple scales. Therefore, in the preparation of high-performance ceramics, especially structural-functional integrated ceramics, it is essential to optimize powder preparation, employ efficient dispersion techniques, and control molding and sintering processes to minimize agglomeration defects and effectively realize the material's properties.

[0006] Ceramic manufacturing typically employs powder metallurgy, and regardless of the molding process chosen, dispersion is a crucial step. The slurry dispersion process directly impacts the stability, uniformity, and product quality of subsequent molding and sintering. However, dispersion is not the only factor to consider in ceramic material preparation. To ensure the green body can withstand the unavoidable vibrations and damage during green body processing and inter-process transfer, sufficient binder is required to provide good strength. Dispersants and binders compete for adsorption sites on the ceramic powder surface, making it difficult to achieve both ideal dispersion and good green body strength simultaneously in practice. Once the dispersant becomes saturated, it can affect the binder's effectiveness on the powder surface, resulting in low green body strength and poor formability after molding. Conversely, insufficient dispersant addition leads to inadequate dispersion, poor slurry uniformity, and a limited viscosity control range, further impacting subsequent molding and sintering. Currently, the mainstream slurry dispersion process involves directly mixing a single dispersant with the powder raw material and solvent, followed by ball milling for dispersion. However, due to the competitive adsorption mechanism, the dispersion effect of a single dispersant cannot reach its optimal state.

[0007] In view of this, the present invention is hereby proposed. Summary of the Invention

[0008] The primary objective of this invention is to provide a method for preparing ceramic structures that, through the synergistic effect of multi-anchor dispersants and oligo-anchor additives, improves the dispersion effect while ensuring the effective adsorption of the binder, thereby achieving the effective utilization of material properties.

[0009] The second objective of this invention is to provide a ceramic structure with uniform texture and excellent performance.

[0010] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted: This invention provides a method for preparing a ceramic structure, comprising the following steps: S1. Premix the multi-anchor dispersant, oligo-anchor additive and solvent to obtain a composite dispersant solution; S2. The ceramic powder, sintering aid and the composite dispersant solution are subjected to a first dispersion treatment to obtain a dispersion. S3. The solution containing the binder and the dispersion are subjected to a second dispersion treatment to obtain a ceramic slurry; S4. The ceramic slurry is sequentially molded, dried, and sintered to obtain a ceramic structure. The multi-anchor dispersant includes compounds with ≥11 adsorption groups in a single molecule, and the oligo-anchor dispersant includes compounds with ≤10 adsorption groups in a single molecule; the adsorption groups include at least one of hydroxyl, amino, carboxyl, carbonyl and ether oxygen bonds.

[0011] Further, in step S1, the multi-anchor dispersant includes at least one of block copolymer dispersants, graft copolymer dispersants, and homopolymer dispersants.

[0012] Preferably, in step S1, the multi-anchor dispersant includes at least one of polyether-modified polyacrylate block, polyacrylic acid-b-polyethylene glycol, polystyrene-b-polyacrylic acid, styrene-maleic anhydride polymer, ethylene oxide-maleic anhydride copolymer, acrylate-maleic anhydride copolymer, siloxane-acrylic acid copolymer, polymethacrylate C18 alkyl ester, polyvinyl alcohol-grafted polyacrylic acid, and polyvinyl acetate.

[0013] Further, in step S1, the mass of the multi-anchor dispersant is 0.3% to 4% of the mass of the ceramic powder.

[0014] Furthermore, in step S1, the oligo-anchoring agent includes natural oils and / or small molecule compounds; Preferably, in step S1, the oligo-anchoring agent includes at least one of tallow, palm oil, tributyl phosphate, glycerin, herring oil, citric acid, and olive oil.

[0015] Further, in step S1, the mass of the oligo-anchoring agent is 0.5% to 6% of the mass of the ceramic powder; And / or, in step S1, the premixing time is 20~60 min.

[0016] Furthermore, step S2 includes at least one of the following features (1) to (5); (1) The ceramic powder includes at least one of zirconium oxide, silicon nitride, aluminum oxide, aluminum nitride and beryllium oxide; (2) The specific surface area of ​​the ceramic powder is 1~30m². 2 / g; (3) The sintering aids include at least one of yttrium nitride, yttrium oxide, lanthanum oxide, ytterbium oxide, magnesium oxide, magnesium nitride, magnesium silicon nitride, magnesium stearate, magnesium fluoride, calcium fluoride, lithium fluoride, titanium oxide, manganese oxide, nickel oxide, iron oxide, boron carbide, carbon black, iron, magnesium, boron, lithium oxide, lithium hydroxide, yttrium nitrate, aluminum nitrate, lithium carbonate, and aluminum oxide; (4) The mass of the sintering aid is 0.2% to 10% of the mass of the ceramic powder; (5) The time for the first dispersion treatment is 4~120h.

[0017] Furthermore, step S3 includes at least one of the following features (1) to (3); (1) The adhesive comprises at least one of polyvinyl alcohol and its derivatives, polyolefins, cellulose and its derivatives, polyethylene glycol, polyethylene oxide, polyacrylate, amide compounds, natural polysaccharides, epoxy resins and polyurethanes; (2) The mass of the binder is 1% to 60% of the mass of the ceramic powder; (3) The second dispersion treatment time is 4~120h.

[0018] Furthermore, in step S3, the solution containing the binder also includes a plasticizer; the plasticizer includes at least one of ester plasticizers, polyether plasticizers, alcohol plasticizers, fatty acid and its derivative plasticizers, low molecular weight polymer plasticizers, and natural oil plasticizers; the mass of the plasticizer is 30% to 80% of the mass of the binder.

[0019] The present invention also provides a ceramic structure, which is prepared by the method described above.

[0020] Furthermore, it includes at least one of the following features (1) to (3); (1) The ceramic structure includes a bioceramic structure, wherein the three-point bending strength of the bioceramic structure is >600 MPa and the light transmittance is >23 / 1 mm; (2) The ceramic structure includes a ceramic substrate, wherein the three-point bending strength of the ceramic substrate is >800 MPa and the thermal conductivity is >70 W / (m·K). (3) The ceramic structure includes large ceramic structural components, and the three-point bending strength of the large ceramic structural components is >350 MPa.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows: The method for preparing the ceramic structure of the present invention increases the amount of dispersant and improves the dispersion effect by using a multi-anchor dispersant and a oligo-anchor additive for synergistic dispersion; and ensures the effective adsorption of the binder by the substitution effect of the binder and the oligo-anchor additive. This improves the strength, toughness, and demolding properties of the dried ceramic green body. The resulting ceramic structure has its internal agglomeration defects effectively eliminated, resulting in a uniform texture, which is conducive to the full development of properties such as thermal conductivity, mechanical strength, light transmittance, and fracture toughness. Attached Figure Description

[0022] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0023] Figure 1 This is a demolding image of the green body in Embodiment 2 of the present invention.

[0024] Figure 2 This is a demolding image of the green body of Comparative Example 5 of the present invention. Detailed Implementation

[0025] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings and examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of the invention. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer are followed. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0026] In some embodiments of the present invention, a method for preparing a ceramic structure is provided, comprising the following steps: S1. Premix the multi-anchor dispersant, oligo-anchor additive and solvent to obtain a composite dispersant solution; S2. The ceramic powder, sintering aid and composite dispersant solution are subjected to a first dispersion treatment to obtain a dispersion. S3. The solution containing the binder and the dispersion are subjected to a second dispersion treatment to obtain a ceramic slurry; S4. The ceramic slurry is successively molded, dried and sintered to obtain a ceramic structure. Among them, multi-anchor dispersants include compounds with ≥11 adsorption groups in a single molecule, and oligo-anchor dispersants include compounds with ≤10 adsorption groups in a single molecule; the adsorption groups include at least one of hydroxyl, amino, carboxyl, carbonyl and ether oxygen bonds.

[0027] Compounds with ≥11 adsorption groups in a single molecule (multi-anchor dispersants) refer to compounds that have ≥11 adsorption groups in a single molecule and / or can generate adsorption groups; compounds with ≤10 adsorption groups in a single molecule (oligo-anchor dispersants) refer to compounds that have ≤10 adsorption groups in a single molecule and / or can generate adsorption groups; the adsorption groups include at least one of hydroxyl, amino, carboxyl, carbonyl and ether oxygen bonds; the adsorption groups can be adsorbed onto the particle surface by electrostatic forces.

[0028] This invention employs the synergistic effect of multi-anchor dispersants and oligo-anchor additives for dispersion. Multi-anchor dispersants are compounds whose individual molecules contain or can form at least one of the following adsorption groups: hydroxyl, amino, carboxyl, carbonyl, and ether oxygen bonds. They can be adsorbed onto the particle surface via electrostatic forces, and the number of adsorption groups is ≥11. Oligo-anchor additives are compounds whose individual molecules contain or can form at least one of the following adsorption groups: hydroxyl, amino, carboxyl, carbonyl, and ether oxygen bonds. They can be adsorbed onto the particle surface via electrostatic forces, and the number of adsorption groups is ≤10. Multi-anchor dispersants exhibit excellent anchoring and adsorption effects on the particle surface; while oligo-anchor additives, due to their fewer adsorption groups, have relatively weaker adsorption forces. Under the external forces of processes such as ball milling, an adsorption-desorption balance exists, requiring a larger amount to achieve sufficient dispersion. The synergistic dispersion of multi-anchor dispersants and oligo-anchor additives not only increases the total amount of dispersing additives, but also allows the binder in subsequent processes to replace the adsorption sites of oligo-anchor additives. This ensures that the strength of ceramic green bodies is further improved while maintaining good dispersibility. The replaced oligo-anchor additives remain free in the system and act as partial plasticizers.

[0029] The method for preparing ceramic structures of this invention optimizes the synergistic effect of functional groups of the dispersant based on the traditional direct dispersion process. On the one hand, the addition of multi-anchor dispersants ensures effective dispersion and reduces soft agglomeration and unevenness. On the other hand, the addition of oligo-anchor additives, due to the limited number of anchor points (amino, hydroxyl, carboxyl, carbonyl, and ether oxygen bonds), makes them prone to desorption during dispersion processes such as ball milling, forming an adsorption-desorption equilibrium. This lays the foundation for the subsequent binding agent substitution, while the substituted oligo-anchor additives remain free in the system and exert a plasticizing effect. Ultimately, the addition of oligo-anchor additives increases the total amount of dispersing agents and improves dispersion performance, while also creating adsorption sites that can be replaced by the binding agent, ensuring the bonding strength after molding and increasing the plasticity of the green body.

[0030] The method for preparing ceramic structures of the present invention improves the efficiency and quality stability of the molding dispersion process through the synergistic dispersion effect of multi-anchor dispersants and oligo-anchor additives; it significantly increases the amount of dispersant in the molding formula with good green body strength, thereby more effectively eliminating agglomerates and achieving full dispersion during slurry preparation, while optimizing the green body bonding strength and toughness, thereby enhancing the full utilization of the thermal conductivity, mechanical strength, light transmittance, fracture toughness and other properties of the ceramic structure.

[0031] In some embodiments of the present invention, in step S1, the multi-anchor dispersant includes at least one of block copolymer dispersants, graft copolymer dispersants, and homopolymer dispersants.

[0032] In some embodiments of the present invention, in step S1, the multi-anchor dispersant includes at least one of polyether-modified polyacrylate block copolymer, polyacrylic acid-b-polyethylene glycol, polystyrene-b-polyacrylic acid, styrene-maleic anhydride polymer, ethylene oxide-maleic anhydride copolymer, acrylate-maleic anhydride copolymer, siloxane-acrylic acid copolymer, polymethyl methacrylate C18 alkyl ester (PMMA-co-C18MA), polyvinyl alcohol-grafted polyacrylic acid (PVA-g-PAA), and polyvinyl acetate. Among these, polyether-modified polyacrylate block copolymer, polyacrylic acid-b-polyethylene glycol, and polystyrene-b-polyacrylic acid are block copolymer dispersants; styrene-maleic anhydride polymer, ethylene oxide-maleic anhydride copolymer, acrylate-maleic anhydride copolymer, siloxane-acrylic acid copolymer, and polyvinyl alcohol-grafted polyacrylic acid are graft copolymer dispersants; and polymethyl methacrylate C18 alkyl ester and polyvinyl acetate are homopolymer dispersants.

[0033] In some embodiments of the present invention, in step S1, the mass of the multi-anchor dispersant is 0.3% to 4% of the mass of the ceramic powder; typically, but not limitingly, for example, the mass of the multi-anchor dispersant is 0.3%, 1%, 2%, 3%, 4% of the mass of the ceramic powder and any value between any two thereof; preferably, the mass of the multi-anchor dispersant is 0.5% to 2% of the mass of the ceramic powder.

[0034] In some embodiments of the present invention, in step S1, the oligo-anchoring agent includes natural oils and / or small molecule compounds.

[0035] In some embodiments of the present invention, in step S1, the oligo-anchoring agent includes at least one of tallow, palm oil, tributyl phosphate, glycerol, herring oil, citric acid, and olive oil. Among these, tallow, palm oil, herring oil, and olive oil are natural oils; tributyl phosphate, glycerol, and citric acid are small molecule compounds with clearly defined chemical formulas and molecular weights.

[0036] In some embodiments of the present invention, in step S1, the mass of the oligo-anchoring agent is 0.5% to 6% of the mass of the ceramic powder; typically, but not limitingly, for example, the mass of the oligo-anchoring agent is 0.5%, 1%, 2%, 3%, 4%, 5%, 6% of the mass of the ceramic powder and any value between any two thereof; preferably, the mass of the oligo-anchoring agent is 1% to 4% of the mass of the ceramic powder.

[0037] In slurry systems, dispersants, as additives, aim to separate powder particles from each other. Dispersants play multiple roles in slurries: they help separate powder particles, ensuring uniform bonding between particles and the binder; they maximize the solids content of the slurry, adjust its viscosity, reduce solvent usage, thereby reducing costs and accelerating the drying of the green body during the drying process, thus improving production efficiency; and optimized dispersants are typically fully decomposed during subsequent debinding processes, preventing contamination of the final product.

[0038] There is a contradiction in the dosage of dispersants: too little dispersant leads to incomplete particle dispersion, preventing the binder from uniformly binding all powder particles; too much dispersant results in the dispersant adhering to the particle surface, leading to low binder bonding strength. Both methods ultimately result in insufficient green body strength and various cracking patterns. To address this issue, this invention proposes a dispersion method that utilizes the synergistic effect of multi-anchor dispersants and oligo-anchor additives. This method ensures complete particle dispersion while effectively adhering to the binder and enhancing plasticization to guarantee green body strength and morphology.

[0039] The dispersion mechanism employs a synergistic effect of multi-anchor dispersants and oligo-anchor additives. Multi-anchor dispersants achieve strong adsorption and dispersion through electrostatic repulsion and steric hindrance. Oligo-anchor additives, on the other hand, simply adsorb onto the powder surface, and as the mechanical motion of the ball milling process reaches adsorption-desorption equilibrium, they free up adsorption sites, allowing the binder to function. The desorbed oligo-anchor additives, free in the slurry system, act between polymer long chains, preventing cross-linking and the formation of larger polymer bodies within the green body. This also weakens the forces within the green body, facilitating polymer movement, reducing the yield stress of the green body, and achieving a plasticizing effect.

[0040] In some embodiments of the present invention, in step S1, the solvent includes, but is not limited to, at least one of water, ethanol, toluene, xylene, acetone, butanone, n-hexane, and ethyl acetate.

[0041] In some embodiments of the present invention, in step S1, the volume of the solvent is 100% to 500% of the volume of the ceramic powder; typically, but not limitingly, for example, the volume of the solvent is 100%, 300%, 500% of the volume of the ceramic powder, and any value between any two thereof.

[0042] In some embodiments of the present invention, the premixing time in step S1 is 20 to 60 minutes; typically, but not limitingly, for example, the premixing time can be 20 minutes, 30 minutes, 40 minutes, 50 minutes, 60 minutes, and any value between any two of these.

[0043] In some embodiments of the present invention, in step S1, premixing includes: ball milling; preferably, the ball milling speed is 100~500 r / min; typically, but not limitingly, for example, the ball milling speed can be 100 r / min, 300 r / min, 500 r / min and any value between any two of them.

[0044] Premixing multi-anchor dispersants, oligo-anchor additives, and solvents before adding them to ceramic powder for dispersion can avoid the situation where multi-anchor dispersants are concentrated and adsorbed on the surface of individual ceramic powder particles. This avoids the phenomenon of localized low bonding strength and cracking caused by a small number of ceramic powder particles being strongly adsorbed by multi-anchor dispersants, which affects the effectiveness of the binder.

[0045] In some embodiments of the present invention, in step S2, the ceramic powder includes, but is not limited to, at least one of zirconium oxide, silicon nitride, aluminum oxide, aluminum nitride, and beryllium oxide.

[0046] In some embodiments of the present invention, in step S2, the specific surface area (BET) of the ceramic powder is 1~30 m². 2 / g; typically, but not limitingly, for example, the specific surface area of ​​ceramic powder can be 1m². 2 / g、5m 2 / g, 10m 2 / g, 15m 2 / g、20m 2 / g、25m 2 / g、30m 2 / g and any value between any two thereof; preferably, the specific surface area of ​​the ceramic powder is 2~15m². 2 / g.

[0047] In some embodiments of the present invention, in step S2, the sintering aid is a substance or its precursor whose melting temperature is lower than that of the ceramic powder or which can react with the ceramic powder to promote mass migration. The sintering aid includes at least one of the following: rare earth compounds (yttrium nitride, yttrium oxide, lanthanum oxide, ytterbium oxide), alkaline earth metal compounds (magnesium oxide, magnesium nitride, magnesium silicon nitride, magnesium stearate), halides (magnesium fluoride, calcium fluoride, lithium fluoride), transition metal compounds (such as titanium oxide, manganese oxide, nickel oxide, iron oxide), non-metallic compounds (boron carbide), carbon black, elements (iron, magnesium, boron), alkali metal compounds (lithium oxide, lithium hydroxide), sintering aid precursors (yttrium nitrate, aluminum nitrate, lithium carbonate), and alumina.

[0048] In some embodiments of the present invention, in step S2, the time for the first dispersion treatment is 4 to 120 hours; typically, but not limitingly, for example, the time for the first dispersion treatment can be 4 hours, 10 hours, 50 hours, 100 hours, 120 hours, and any value between any two of them; preferably, the time for the first dispersion treatment is 8 to 36 hours.

[0049] In some embodiments of the present invention, in step S2, the first dispersion process includes ball milling; preferably, the ball milling speed is 100~500 r / min; typically, but not limitingly, for example, the ball milling speed can be 100 r / min, 300 r / min, 500 r / min and any value between any two of them.

[0050] In some embodiments of the present invention, in step S3, the adhesive includes at least one of polyvinyl alcohol and its derivatives, polyolefins, cellulose and its derivatives, polyethylene glycol, polyethylene oxide, polyacrylate, amide compounds, natural polysaccharides, epoxy resins and polyurethanes.

[0051] In some embodiments of the present invention, in step S3, the binder is a substance containing amino, hydroxyl, carboxyl, and other polar groups that can be electrostatically adsorbed onto the surface of the powder. Binders include polyvinyl alcohol, polyvinyl butyral (PVB), polyvinyl formal, polyvinyl acetate, polyethylene, polypropylene, ethylene-vinyl acetate copolymer, polystyrene, ethyl cellulose, methyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose, low molecular weight polyethylene glycol (molecular weight 2000~20000), and high molecular weight polyethylene oxide (molecular weight 1×10⁻⁶). 5 ~1×10 7 ( ), acrylate, polymethyl methacrylate, polyethyl methacrylate, acrylamide-methylenebisacrylamide, starch, dextrin, sodium alginate, epoxy resin and polyurethane.

[0052] In some embodiments of the present invention, in step S3, the mass of the binder is 1% to 60% of the mass of the ceramic powder; typically, but not limitingly, for example, the mass of the binder is 1%, 10%, 20%, 30%, 40%, 50%, 60% of the mass of the ceramic powder and any value between any two thereof.

[0053] This invention significantly improves the strength of dried ceramic green bodies through the substitution effect of binders and oligo-anchoring agents, with the green body strength exceeding 5 MPa.

[0054] In some embodiments of the present invention, in step S3, the solvent of the solution containing the binder includes, but is not limited to, at least one of water, ethanol, toluene, xylene, acetone, butanone, n-hexane, and ethyl acetate.

[0055] In some embodiments of the present invention, in step S3, the concentration of the binder in the solution containing the binder is 3wt% to 40wt%; typically, but not limitingly, for example, the concentration of the binder in the solution containing the binder can be 3wt%, 10wt%, 15wt%, 20wt%, 30wt%, 40wt%, and any value between any two of these.

[0056] In some embodiments of the present invention, in step S3, the time for the second dispersion process is 4 to 120 hours; typically, but not limitingly, for example, the time for the second dispersion process can be 4 hours, 10 hours, 50 hours, 100 hours, 120 hours, and any value between any two of them; preferably, the time for the second dispersion process is 8 to 36 hours.

[0057] In some embodiments of the present invention, in step S3, the second dispersion process includes ball milling; preferably, the ball milling speed is 100~500 r / min; typically, but not limitingly, for example, the ball milling speed can be 100 r / min, 300 r / min, 500 r / min and any value between any two of them.

[0058] In some embodiments of the present invention, in step S3, the solution containing the binder also includes a plasticizer.

[0059] In some embodiments of the present invention, in step S3, the plasticizer includes at least one of ester plasticizers, polyether plasticizers, alcohol plasticizers, fatty acid and its derivative plasticizers, low molecular weight polymer plasticizers, and natural oil plasticizers.

[0060] In some embodiments of the present invention, in step S3, the plasticizer includes at least one of the following: ester plasticizers (triethylene glycol diisooctyl ester, dioctyl phthalate, dibutyl phthalate, tributyl acetyl citrate, dioctyl adipate, dibutyl adipate, triphenyl phosphate), polyether plasticizers, alcohol plasticizers (glycerol, sorbitol, polyethylene glycol (PEG)), fatty acid and its derivative plasticizers (oleic acid, stearic acid, oleamide, butyl stearate, calcium stearate, lithium stearate, zinc stearate), low molecular weight polymer plasticizers (low molecular weight PVA, low molecular weight PMMA, liquid rubber), and natural oil plasticizers (castor oil, linseed oil, soybean oil derivatives).

[0061] In some embodiments of the present invention, in step S3, the mass of the plasticizer is 30% to 80% of the mass of the binder; typically, but not limitingly, the mass of the plasticizer is 30%, 40%, 50%, 60%, 70%, 80% of the mass of the binder and any value between any two thereof; preferably, the mass of the plasticizer is 40% to 60% of the mass of the binder.

[0062] This invention improves the toughness and demolding properties of green bodies through the synergistic effect of plasticizers and oligo-anchoring agents; and enhances the strength, thermal conductivity, stability, and other properties of green bodies and ceramic structures through the synergistic plasticizing effect of plasticizers and oligo-anchoring agents.

[0063] This invention effectively ensures dispersion by using a combination of multi-anchor dispersants and oligo-anchor additives, resulting in lower slurry viscosity.

[0064] In some embodiments of the present invention, in step S3, the ceramic slurry is shaped and dried to obtain a ceramic green body; after the ceramic green body is sintered, a ceramic structure is obtained.

[0065] In some embodiments of the present invention, in step S3, the ceramic slurry also includes a defoamer; if no defoamer is present, the ceramic slurry needs to be vacuum defoamed before molding and drying.

[0066] In some embodiments of the present invention, step S3, molding drying includes at least one of spray granulation, spray drying, dry pressing, cold isostatic pressing, slurry molding, and casting drying.

[0067] Ceramic slurry is processed using different molding and drying processes (spray granulation, spray + dry pressing, slurry casting, tape casting, etc.) depending on the application field, structural shape, and product process. Then, it is debonded and sintered. The resulting ceramic structure has the characteristics of uniform product and excellent performance in the fields of heat, light, and force.

[0068] In some embodiments of the present invention, a ceramic structure is also provided, which is prepared by the above-described method for preparing ceramic structures.

[0069] The ceramic structure prepared by this invention has a uniform texture and can improve thermal conductivity, mechanical strength, light transmittance and fracture toughness by more than 5% compared with conventional processes, which significantly improves the overall performance of the ceramic structure.

[0070] In some embodiments of the present invention, the ceramic structure includes a bioceramic structure, wherein the three-point flexural strength of the bioceramic structure is >600 MPa and the light transmittance is >23 / 1 mm. Three-point flexural strength: test method is GB-T 6569-2006; light transmittance: ISO 6872:2015 Annex D (colorimetric method); calculation formula: TP = .

[0071] In some embodiments of the present invention, the ceramic structure includes a ceramic substrate, wherein the three-point flexural strength of the ceramic substrate is >800 MPa, the thermal conductivity is >70 W / (m·K), and the green strength is >5 MPa; preferably, the three-point flexural strength of the ceramic substrate is >850 MPa, the thermal conductivity is >75 W / (m·K), and the green strength is >6 MPa. Three-point flexural strength: the test method is GB-T 6569-2006; thermal conductivity: the transient planar heat source method is used, and the equipment is a Hot Disk TPS-2500-Si3N4 thermal conductivity meter; green strength: a universal testing machine (CMT6503), manufactured by Metersbonwe Industries, USA; Si3N4 cast green blanks are cut into pieces with dimensions of 4mm×4mm×30mm, the tensile speed is 0.5mm / min, and the strength and elongation of multiple green blank samples are tested at room temperature, and the average value is taken as the test result.

[0072] In some embodiments of the present invention, the ceramic structure includes a large ceramic structural member, wherein the three-point bending strength of the large ceramic structural member is >350 MPa; preferably, the three-point bending strength of the large ceramic structural member is >375 MPa, and the fracture toughness is >3.8 MPa·m. 1 / 2 Three-point flexural strength: Test method is GB-T 6569-2006; Fracture toughness: ASTM C1421-10 Standard test method for determining fracture toughness of advanced ceramics at room temperature.

[0073] Example 1 The method for preparing the ceramic structure provided in this embodiment includes the following steps: One part of polymethyl methacrylate C18 alkyl ester (PMMA-co-C18MA), two parts of herring oil, and 100 parts of toluene were ball-milled at 300 r / min for 30 min. Then add 91 parts of zirconium oxide, 8.8 parts of yttrium oxide and 0.2 parts of aluminum oxide, and continue ball milling at 300 r / min for 8 hours; Add 3 parts polypropylene, 1.2 parts PEG and 50 parts n-hexane, and continue ball milling at 300 r / min for 12 h to obtain ceramic slurry; The ceramic slurry is then subjected to spray granulation, dry pressing, and cold isostatic pressing to obtain a ceramic green body; after the ceramic green body is debonded and sintered, a ceramic structure is obtained. The spray granulation process includes an inlet temperature of 80℃, an outlet temperature of 120℃, and a rotation speed of 15000 r / min; dry pressing includes holding at 200 MPa for 20 seconds; cold isostatic pressing includes cold isostatic pressing at 300 MPa for 10 minutes; and debonding sintering includes holding at 1000℃ for 1 hour in air atmosphere, followed by heating to 1450℃ and holding for 3 hours.

[0074] Example 2 The method for preparing the ceramic structure provided in this embodiment includes the following steps: 0.5 parts of polyvinyl alcohol grafted polyacrylic acid (PVA-g-PAA), 1 part of citric acid and 100 parts of anhydrous ethanol were ball-milled at 300 r / min for 30 min. Then add 94 parts of silicon nitride, 3 parts of yttrium oxide and 3 parts of magnesium oxide, and continue ball milling at 300 r / min for 12 h; Add 20 parts PVB, 8 parts dioctyl phthalate and 100 parts anhydrous ethanol, and ball mill at 300 r / min for 12 h to obtain ceramic slurry; Then, the ceramic slurry was subjected to vacuum degassing for 2 hours under a vacuum of 0.8 MPa and then cast and dried to obtain a ceramic green body. After the ceramic green body was demolded, it was subjected to air degreasing (degreasing for 60 hours, peak temperature 400℃) and sintering at 1840℃ for 5 hours to obtain a ceramic structure.

[0075] Example 3 The method for preparing the ceramic structure provided in this embodiment includes the following steps: Two parts of polyvinyl acetate, four parts of olive oil, and 50 parts of toluene were ball-milled at 300 r / min for 30 min. Then add 99.65 parts of α-alumina and 0.2 parts of magnesium oxide, and continue ball milling at 300 r / min for 6 hours; Add 1.5 parts of polypropylene and 40 parts of n-hexane, and ball mill at 300 r / min for 6 h to obtain ceramic slurry; Then, the ceramic slurry was subjected to vacuum degassing at -0.8MPa for 2 hours, then allowed to stand for aging for 12 hours and then cast into a ceramic green body; after sintering the ceramic green body, a ceramic structure was obtained. The process of grouting includes: grouting simultaneously with the inner and outer molds for 10 hours, continuing to absorb liquid for 2 hours after grout discharge, and demolding and drying for 72 hours; the process of sintering includes: heat treatment at 1720℃ for 3 hours in an air atmosphere.

[0076] Comparative Example 1 The method for preparing the ceramic structure provided in this comparative example includes the following steps: Three parts of polymethyl methacrylate C18 alkyl ester (PMMA-co-C18MA) and 100 parts of toluene were ball-milled at 300 r / min for 30 min. Then add 91 parts of zirconium oxide, 8.8 parts of yttrium oxide and 0.2 parts of aluminum oxide, and continue ball milling at 300 r / min for 8 hours; Add 3 parts polypropylene, 1.2 parts PEG and 50 parts n-hexane, and continue ball milling at 300 r / min for 12 h to obtain ceramic slurry; The ceramic slurry is then subjected to spray granulation, dry pressing, and cold isostatic pressing to obtain a ceramic green body; after the ceramic green body is debonded and sintered, a ceramic structure is obtained. The spray granulation process includes an inlet temperature of 80℃, an outlet temperature of 120℃, and a rotation speed of 15000 r / min; dry pressing includes holding at 200 MPa for 20 seconds; cold isostatic pressing includes cold isostatic pressing at 300 MPa for 10 minutes; and debonding sintering includes holding at 1000℃ for 1 hour in air atmosphere, followed by heating to 1450℃ and holding for 3 hours.

[0077] Comparative Example 2 The method for preparing the ceramic structure provided in this comparative example includes the following steps: Three parts of herring oil and 100 parts of toluene were ball-milled at 300 r / min for 30 min. Then add 91 parts of zirconium oxide, 8.8 parts of yttrium oxide and 0.2 parts of aluminum oxide, and continue ball milling at 300 r / min for 8 hours; Add 3 parts polypropylene, 1.2 parts PEG and 50 parts n-hexane, and continue ball milling at 300 r / min for 12 h to obtain ceramic slurry; The ceramic slurry is then subjected to spray granulation, dry pressing, and cold isostatic pressing to obtain a ceramic green body; after the ceramic green body is debonded and sintered, a ceramic structure is obtained. The spray granulation process includes an inlet temperature of 80℃, an outlet temperature of 120℃, and a rotation speed of 15000 r / min; dry pressing includes holding at 200 MPa for 20 seconds; cold isostatic pressing includes cold isostatic pressing at 300 MPa for 10 minutes; and debonding sintering includes holding at 1000℃ for 1 hour in air atmosphere, followed by heating to 1450℃ and holding for 3 hours.

[0078] Comparative Example 3 The method for preparing the ceramic structure provided in this comparative example includes the following steps: One part of polymethyl methacrylate C18 alkyl ester (PMMA-co-C18MA), two parts of herring oil, 100 parts of toluene, 91 parts of zirconium oxide, 8.8 parts of yttrium oxide, and 0.2 parts of alumina were mixed and ball-milled at 300 r / min for 8 h. Add 3 parts polypropylene, 1.2 parts PEG and 50 parts n-hexane, and continue ball milling at 300 r / min for 12 h to obtain ceramic slurry; The ceramic slurry is then subjected to spray granulation, dry pressing, and cold isostatic pressing to obtain a ceramic green body; after the ceramic green body is debonded and sintered, a ceramic structure is obtained. The spray granulation process includes an inlet temperature of 80℃, an outlet temperature of 120℃, and a rotation speed of 15000 r / min; dry pressing includes holding at 200 MPa for 20 seconds; cold isostatic pressing includes cold isostatic pressing at 300 MPa for 10 minutes; and debonding sintering includes holding at 1000℃ for 1 hour in air atmosphere, followed by heating to 1450℃ and holding for 3 hours.

[0079] Comparative Example 4 The method for preparing the ceramic structure provided in this comparative example includes the following steps: 0.2 parts of polymethyl methacrylate C18 alkyl ester (PMMA-co-C18MA), 0.4 parts of herring oil and 100 parts of toluene were ball-milled at 300 r / min for 30 min; Then add 91 parts of zirconium oxide, 8.8 parts of yttrium oxide and 0.2 parts of aluminum oxide, and continue ball milling at 300 r / min for 8 hours; Add 3 parts polypropylene, 1.2 parts PEG and 50 parts n-hexane, and continue ball milling at 300 r / min for 12 h to obtain ceramic slurry; The ceramic slurry is then subjected to spray granulation, dry pressing, and cold isostatic pressing to obtain a ceramic green body; after the ceramic green body is debonded and sintered, a ceramic structure is obtained. The spray granulation process includes an inlet temperature of 80℃, an outlet temperature of 120℃, and a rotation speed of 15000 r / min; dry pressing includes holding at 200 MPa for 20 seconds; cold isostatic pressing includes cold isostatic pressing at 300 MPa for 10 minutes; and debonding sintering includes holding at 1000℃ for 1 hour in air atmosphere, followed by heating to 1450℃ and holding for 3 hours.

[0080] Comparative Example 5 The method for preparing the ceramic structure provided in this comparative example includes the following steps: 1.5 parts of polyvinyl alcohol grafted polyacrylic acid (PVA-g-PAA) and 100 parts of anhydrous ethanol were ball-milled at 300 r / min for 30 min. Then add 94 parts of silicon nitride, 3 parts of yttrium oxide and 3 parts of magnesium oxide, and continue ball milling at 300 r / min for 12 h; Add 20 parts PVB, 8 parts dioctyl phthalate and 100 parts anhydrous ethanol, and ball mill at 300 r / min for 12 h to obtain ceramic slurry; Then, the ceramic slurry was subjected to vacuum degassing for 2 hours under a vacuum of 0.8 MPa and then cast and dried to obtain a ceramic green body. After the ceramic green body was demolded, it was subjected to air degreasing (degreasing for 60 hours, peak temperature 400℃) and sintering at 1840℃ for 5 hours to obtain a ceramic structure.

[0081] Comparative Example 6 The method for preparing the ceramic structure provided in this comparative example includes the following steps: 1.5 parts of citric acid and 100 parts of anhydrous ethanol were ball-milled at 300 r / min for 30 min; Then add 94 parts of silicon nitride, 3 parts of yttrium oxide and 3 parts of magnesium oxide, and continue ball milling at 300 r / min for 12 h; Add 20 parts PVB, 8 parts dioctyl phthalate and 100 parts anhydrous ethanol, and ball mill at 300 r / min for 12 h to obtain ceramic slurry; Then, the ceramic slurry was subjected to vacuum degassing for 2 hours under a vacuum of 0.8 MPa and then cast and dried to obtain a ceramic green body. After the ceramic green body was demolded, it was subjected to air degreasing (degreasing for 60 hours, peak temperature 400℃) and sintering at 1840℃ for 5 hours to obtain a ceramic structure.

[0082] Comparative Example 7 The method for preparing the ceramic structure provided in this comparative example includes the following steps: Mix 0.5 parts of polyvinyl alcohol grafted polyacrylic acid (PVA-g-PAA), 1 part of citric acid, 100 parts of anhydrous ethanol, 94 parts of silicon nitride, 3 parts of yttrium oxide and 3 parts of magnesium oxide, and ball mill at 300 r / min for 12 h. Add 20 parts PVB, 8 parts dioctyl phthalate and 100 parts anhydrous ethanol, and ball mill at 300 r / min for 12 h to obtain ceramic slurry; Then, the ceramic slurry was subjected to vacuum degassing for 2 hours under a vacuum of 0.8 MPa and then cast and dried to obtain a ceramic green body. After the ceramic green body was demolded, it was subjected to air degreasing (degreasing for 60 hours, peak temperature 400℃) and sintering at 1840℃ for 5 hours to obtain a ceramic structure.

[0083] Comparative Example 8 The method for preparing the ceramic structure provided in this comparative example includes the following steps: 4.5 parts of polyvinyl alcohol grafted polyacrylic acid (PVA-g-PAA), 6.5 parts of citric acid and 100 parts of anhydrous ethanol were ball-milled at 300 r / min for 30 min. Then add 94 parts of silicon nitride, 3 parts of yttrium oxide and 3 parts of magnesium oxide, and continue ball milling at 300 r / min for 12 h; Add 20 parts PVB, 8 parts dioctyl phthalate and 100 parts anhydrous ethanol, and ball mill at 300 r / min for 12 h to obtain ceramic slurry; Then, the ceramic slurry was subjected to vacuum degassing for 2 hours under a vacuum of 0.8 MPa and then cast and dried to obtain a ceramic green body. After the ceramic green body was demolded, it was subjected to air degreasing (degreasing for 60 hours, peak temperature 400℃) and sintering at 1840℃ for 5 hours to obtain a ceramic structure.

[0084] Comparative Example 9 The method for preparing the ceramic structure provided in this comparative example includes the following steps: Six parts of polyvinyl acetate and 50 parts of toluene were ball-milled at 300 r / min for 30 min. Then add 99.65 parts of α-alumina and 0.2 parts of magnesium oxide, and continue ball milling at 300 r / min for 6 hours; Add 1.5 parts of polypropylene and 40 parts of n-hexane, and ball mill at 300 r / min for 6 h to obtain ceramic slurry; Then, the ceramic slurry was subjected to vacuum degassing at -0.8MPa for 2 hours, then allowed to stand for aging for 12 hours and then cast into a ceramic green body; after sintering the ceramic green body, a ceramic structure was obtained. The process of grouting includes: grouting simultaneously with the inner and outer molds for 10 hours, continuing to absorb liquid for 2 hours after grout discharge, and demolding and drying for 72 hours; the process of sintering includes: heat treatment at 1720℃ for 3 hours in an air atmosphere.

[0085] Comparative Example 10 The method for preparing the ceramic structure provided in this comparative example includes the following steps: Ball mill 6 parts olive oil and 50 parts toluene at 300 r / min for 30 min; Then add 99.65 parts of α-alumina and 0.2 parts of magnesium oxide, and continue ball milling at 300 r / min for 6 hours; Add 1.5 parts of polypropylene and 40 parts of n-hexane, and ball mill at 300 r / min for 6 h to obtain ceramic slurry; Then, the ceramic slurry was subjected to vacuum degassing at -0.8MPa for 2 hours, then allowed to stand for aging for 12 hours and then cast into a ceramic green body; after sintering the ceramic green body, a ceramic structure was obtained. The process of grouting includes: grouting simultaneously with the inner and outer molds for 10 hours, continuing to absorb liquid for 2 hours after grout discharge, and demolding and drying for 72 hours; the process of sintering includes: heat treatment at 1720℃ for 3 hours in an air atmosphere.

[0086] Comparative Example 11 The method for preparing the ceramic structure provided in this comparative example includes the following steps: Mix 2 parts polyvinyl acetate, 4 parts olive oil, 50 parts toluene, 99.65 parts α-alumina and 0.2 parts magnesium oxide, and ball mill at 300 r / min for 6 h; Add 1.5 parts of polypropylene and 40 parts of n-hexane, and ball mill at 300 r / min for 6 h to obtain ceramic slurry; Then, the ceramic slurry was subjected to vacuum degassing at -0.8MPa for 2 hours, then allowed to stand for aging for 12 hours and then cast into a ceramic green body; after sintering the ceramic green body, a ceramic structure was obtained. The process of grouting includes: grouting simultaneously with the inner and outer molds for 10 hours, continuing to absorb liquid for 2 hours after grout discharge, and demolding and drying for 72 hours; the process of sintering includes: heat treatment at 1720℃ for 3 hours in an air atmosphere.

[0087] Comparative Example 12 The method for preparing the ceramic structure provided in this comparative example includes the following steps: 4.5 parts of polyvinyl acetate, 0.3 parts of olive oil and 50 parts of toluene were ball-milled at 300 r / min for 30 min; Then add 99.65 parts of α-alumina and 0.2 parts of magnesium oxide, and continue ball milling at 300 r / min for 6 hours; Add 1.5 parts of polypropylene and 40 parts of n-hexane, and ball mill at 300 r / min for 6 h to obtain ceramic slurry; Then, the ceramic slurry was subjected to vacuum degassing at -0.8MPa for 2 hours, then allowed to stand for aging for 12 hours and then cast into a ceramic green body; after sintering the ceramic green body, a ceramic structure was obtained. The process of grouting includes: grouting simultaneously with the inner and outer molds for 10 hours, continuing to absorb liquid for 2 hours after grout discharge, and demolding and drying for 72 hours; the process of sintering includes: heat treatment at 1720℃ for 3 hours in an air atmosphere.

[0088] Test case Detection method: Three-point flexural strength: The test method is GB-T 6569-2006; Thermal conductivity testing: The transient planar heat source method was used, and the equipment adopted was a Hot Disk TPS-2500-Si3N4 thermal conductivity meter. Fracture toughness: ASTM C1421-10 Standard test method for determining fracture toughness of advanced ceramics at room temperature; Viscosity: Rotational viscometer: Shanghai Pingxuan Scientific Instruments Co., Ltd., model NDJ-9S; Tensile strength: Universal testing machine (CMT6503), Meters Industries, USA; Si3N4 cast green blanks were cut into pieces with dimensions of 4mm×4mm×30mm, tensile speed was 0.5mm / min, and the strength and elongation of multiple green blank samples were tested at room temperature, and the average value was taken as the test result; Light transmittance: ISO 6872:2015 Annex D (colorimetric method); Calculation formula: TP= .

[0089] The viscosity of the ceramic slurry, the light transmittance (TP) of the ceramic structure, and the three-point flexural strength of Examples 1 and Comparative Examples 1-4 were tested, and the results are shown in Table 1.

[0090] Table 1

[0091] As shown in Table 1, compared with Example 1, Comparative Example 1 did not add any oligo-anchor point additives, and only the multi-anchor point dispersant played a dispersing role. In this case, the effective sites of the binder were significantly reduced, resulting in a significant decrease in flexural strength. Compared with Example 1, Comparative Example 2 did not add any multi-anchor point dispersant, and only the oligo-anchor point additives played a dispersing role. The dispersion effect was not as good as that of Example 1, and the viscosity, transmittance parameters, and flexural strength of the slurry were all deteriorated to varying degrees. Compared with Example 1, Comparative Example 3 omitted the pre-grinding step, resulting in uneven initial dispersion of the dispersant. A small number of particle adsorption sites were fully loaded by the multi-anchor point dispersant, causing a sharp decrease in local flexural strength. Compared with Example 1, Comparative Example 4 had different amounts of multi-anchor point dispersant and oligo-anchor point additives, and the overall dispersion effect, slurry viscosity, transmittance parameters, and flexural strength were all significantly deteriorated.

[0092] The viscosity of the ceramic slurry, the thermal conductivity of the ceramic structure, the three-point flexural strength, and the strength of the ceramic green body were tested for Examples 2 and Comparative Examples 5-8. The results are shown in Table 2. The green body demolding of Example 2 is as follows: Figure 1 As shown; the demolding of the green body in Comparative Example 5 is as follows. Figure 2 As shown.

[0093] Table 2

[0094] From Table 2, Figure 1 and Figure 2It can be seen that, compared with Example 2, Comparative Example 5 did not add oligo-anchor point additives, and only multi-anchor point dispersants played a dispersing role. At this time, the effective sites of the binder were greatly reduced, resulting in obvious reductions in flexural strength, thermal conductivity, and green strength. Furthermore, due to the lack of migration and plasticization by oligo-anchor point additives, the difficulty of green demolding increased. Compared with Example 2, Comparative Example 6 did not add multi-anchor point dispersants, and only oligo-anchor point additives played a dispersing role. The dispersion effect was not as good as that of Example 2, and the viscosity, thermal conductivity, green strength, and flexural strength of the slurry were all deteriorated to varying degrees. Compared with Example 2, Comparative Example 7 omitted the pre-grinding step, resulting in uneven initial dispersion of the dispersant. A small number of particle adsorption sites were fully loaded by the multi-anchor point dispersant, causing local flexural strength, thermal conductivity, and green strength, and a sharp decrease in the overall slurry viscosity. Compared with Example 2, Comparative Example 8 had different amounts of multi-anchor point dispersants and oligo-anchor point additives, resulting in significant deterioration in the overall dispersion effect, slurry viscosity, green strength, thermal conductivity, and flexural strength.

[0095] The viscosity of the ceramic slurry, the fracture toughness of the ceramic structure, and the three-point bending strength of Examples 3 and Comparative Examples 9-12 were tested, and the results are shown in Table 3.

[0096] Table 3

[0097] As shown in Table 3, in Comparative Example 9, compared with Example 3, no oligo-anchoring agent was added, and only the multi-anchoring dispersant played a dispersing role. In this case, the effective sites of the binder were significantly reduced, resulting in a significant decrease in flexural strength and fracture toughness. In Comparative Example 10, compared with Example 3, no multi-anchoring dispersant was added, and only the oligo-anchoring agent played a dispersing role. The dispersion effect was not as good as in Example 3, and the viscosity, flexural strength, and fracture toughness of the slurry were all deteriorated to varying degrees. In Comparative Example 11, compared with Example 3, the pre-grinding step was omitted, resulting in uneven initial dispersion of the dispersant. A small number of particle adsorption sites were fully loaded by the multi-anchoring dispersant, causing a sharp decrease in local flexural strength and fracture toughness. In Comparative Example 12, compared with Example 3, the selected multi-anchoring dispersant and oligo-anchoring agent were not in the optimal range, and the overall dispersion effect, slurry viscosity, fracture toughness, and flexural strength were all significantly deteriorated.

[0098] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for producing a ceramic structure, characterized by, Includes the following steps: S1. Premix the multi-anchor dispersant, oligo-anchor additive and solvent to obtain a composite dispersant solution; S2. The ceramic powder, sintering aid and the composite dispersant solution are subjected to a first dispersion treatment to obtain a dispersion. S3. The solution containing the binder and the dispersion are subjected to a second dispersion treatment to obtain a ceramic slurry; S4. The ceramic slurry is sequentially molded, dried, and sintered to obtain a ceramic structure. The multi-anchor dispersant includes compounds with ≥11 adsorption groups in a single molecule, and the oligo-anchor dispersant includes compounds with ≤10 adsorption groups in a single molecule; the adsorption groups include at least one of hydroxyl, amino, carboxyl, carbonyl and ether oxygen bonds.

2. The method for preparing the ceramic structure according to claim 1, characterized in that, In step S1, the multi-anchor dispersant includes at least one of block copolymer dispersants, graft copolymer dispersants, and homopolymer dispersants; Preferably, in step S1, the multi-anchor dispersant includes at least one of polyether-modified polyacrylate block, polyacrylic acid-b-polyethylene glycol, polystyrene-b-polyacrylic acid, styrene-maleic anhydride polymer, ethylene oxide-maleic anhydride copolymer, acrylate-maleic anhydride copolymer, siloxane-acrylic acid copolymer, polymethacrylate C18 alkyl ester, polyvinyl alcohol-grafted polyacrylic acid, and polyvinyl acetate.

3. The method for preparing the ceramic structure according to claim 1, characterized in that, In step S1, the mass of the multi-anchor dispersant is 0.3% to 4% of the mass of the ceramic powder.

4. The method for preparing the ceramic structure according to claim 1, characterized in that, In step S1, the oligo-anchoring agent includes natural oils and / or small molecule compounds; Preferably, in step S1, the oligo-anchoring agent includes at least one of tallow, palm oil, tributyl phosphate, glycerin, herring oil, citric acid, and olive oil.

5. The method for preparing the ceramic structure according to claim 1, characterized in that, In step S1, the mass of the oligo-anchoring agent is 0.5% to 6% of the mass of the ceramic powder; And / or, in step S1, the premixing time is 20~60 min.

6. The method for preparing the ceramic structure according to claim 1, characterized in that, Step S2 includes at least one of the following features (1) to (5); (1) The ceramic powder includes at least one of zirconium oxide, silicon nitride, aluminum oxide, aluminum nitride and beryllium oxide; (2) the specific surface area of the ceramic powder is 1-30 m 2 / g; (3) The sintering aids include at least one of yttrium nitride, yttrium oxide, lanthanum oxide, ytterbium oxide, magnesium oxide, magnesium nitride, magnesium silicon nitride, magnesium stearate, magnesium fluoride, calcium fluoride, lithium fluoride, titanium oxide, manganese oxide, nickel oxide, iron oxide, boron carbide, carbon black, iron, magnesium, boron, lithium oxide, lithium hydroxide, yttrium nitrate, aluminum nitrate, lithium carbonate, and aluminum oxide; (4) The mass of the sintering aid is 0.2% to 10% of the mass of the ceramic powder; (5) The time for the first dispersion treatment is 4~120h.

7. The method for preparing the ceramic structure according to claim 1, characterized in that, Step S3 includes at least one of the following features (1) to (3); (1) The adhesive comprises at least one of polyvinyl alcohol and its derivatives, polyolefins, cellulose and its derivatives, polyethylene glycol, polyethylene oxide, polyacrylate, amide compounds, natural polysaccharides, epoxy resins and polyurethanes; (2) The mass of the binder is 1% to 60% of the mass of the ceramic powder; (3) The second dispersion treatment time is 4~120h.

8. The method for preparing the ceramic structure according to claim 1, characterized in that, In step S3, the solution containing the binder also includes a plasticizer; the plasticizer includes at least one of ester plasticizers, polyether plasticizers, alcohol plasticizers, fatty acid and its derivative plasticizers, low molecular weight polymer plasticizers and natural oil plasticizers; the mass of the plasticizer is 30% to 80% of the mass of the binder.

9. A ceramic structure, characterized in that, The ceramic structure was prepared by any one of claims 1 to 8.

10. The ceramic structure according to claim 9, characterized in that, Includes at least one of the following features (1) to (3); (1) The ceramic structure includes a bioceramic structure, wherein the three-point bending strength of the bioceramic structure is >600 MPa and the light transmittance is >23 / 1 mm; (2) The ceramic structure includes a ceramic substrate, wherein the three-point bending strength of the ceramic substrate is >800 MPa and the thermal conductivity is >70 W / (m·K). (3) The ceramic structure includes large ceramic structural components, and the three-point bending strength of the large ceramic structural components is >350 MPa.

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