Silicon oxide ceramic core and method for producing the same

Abstract

The application discloses a silica ceramic core and a preparation method thereof. The preparation method of the silica ceramic core comprises the following steps: preparing a ceramic slurry, wherein the ceramic slurry comprises ceramic particles, and the ceramic particles comprise silica and silicon nitride; preparing a ceramic matrix blank by means of light-curing 3D printing based on the ceramic slurry; pre-sintering the ceramic matrix blank to obtain a ceramic matrix; preparing an additive solution, impregnating the additive solution into the ceramic matrix, and then performing a heating reaction; and then performing sintering to obtain the silica ceramic core. The application solves the problem of easy scattering caused by the low relative refractive index of the ceramic slurry in the process of preparing the silica ceramic core by means of light-curing 3D printing of the silica ceramic, thereby avoiding the decrease of the forming precision, and the silica ceramic core is easy to demold, and the problem of the rough surface of a casted part caused by the high porosity of the ceramic core during casting is avoided.

Description

Technical Field

[0001] This invention relates to the field of ceramic core technology, specifically to a silicon oxide ceramic core and its preparation method. Background Technology

[0002] With the development of aerospace technology, the shapes of ceramic cores used for nickel-based high-temperature alloy casting are becoming increasingly complex. Traditional hot press molding can no longer meet the needs of rapid manufacturing of new hollow blades. Photopolymerization 3D printing can achieve rapid manufacturing of silicon oxide cores. However, due to the low relative refractive index of silicon oxide ceramics and photopolymerization resin, scattering is prone to occur during photopolymerization, resulting in a decrease in molding accuracy and failing to meet the high-precision requirements of core casting.

[0003] Therefore, improving the forming accuracy in the process of preparing silica ceramic cores by 3D printing has become a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing a silica ceramic core, which solves the problems of low relative refractive index and easy scattering of the ceramic slurry during the preparation of silica ceramic cores by 3D printing, thereby avoiding a decrease in molding accuracy; and ensuring that the critical exposure energy of the silica ceramic slurry is ≥173.14 mJ / cm. 2 The critical curing thickness is less than or equal to ≤356.38μm, resulting in high molding accuracy, which meets the high precision requirements of ceramic core casting. Furthermore, the prepared ceramic core has a silicon oxide content of ≥99.5% and a high porosity, making it easy to demold and avoiding the problem of uneven surface of the casting due to high porosity during ceramic core casting.

[0005] According to one aspect of the present invention, a method for preparing a silicon oxide ceramic core is provided, comprising the following steps:

[0006] A ceramic slurry is prepared, the ceramic slurry comprising ceramic particles, the ceramic particles comprising silicon oxide and silicon nitride; a ceramic matrix preform is prepared by photopolymerization 3D printing based on the ceramic slurry.

[0007] The ceramic matrix is ​​obtained by pre-sintering the ceramic matrix green body;

[0008] A solution of additives is prepared, which is then impregnated into a ceramic matrix, followed by a heating reaction.

[0009] Then, sintering is performed to obtain a silicon oxide ceramic core; preferably, the critical exposure energy of the ceramic slurry is ≥178 mJ / cm. 2 The critical curing thickness is ≥320μm, and the silicon oxide content in the prepared ceramic core is ≥99.5%.

[0010] The advantages of this invention over existing technologies lie in the fact that, by including silicon oxide and silicon nitride in the ceramic particles, specifically by introducing silicon nitride, the ceramic slurry achieves a high relative refractive index when used to prepare ceramic matrix green bodies via 3D printing. This significantly reduces scattering during photocuring, thereby achieving a high critical exposure energy of ≥178 mJ / cm² for the ceramic slurry. 2 The critical curing thickness is ≤320μm, resulting in high precision in the forming of ceramic matrix preforms.

[0011] By preparing an additive solution and impregnating it into a ceramic matrix, followed by heating, the additive is introduced into the ceramic matrix. This facilitates the reaction with silicon nitride in the ceramic matrix, converting silicon nitride into silicon oxide and increasing the silicon oxide content in the final silicon oxide ceramic core. At the same time, the additive improves the surface density of the silicon oxide ceramic core, which is beneficial for achieving a smooth surface of the casting obtained when the silicon oxide ceramic core is cast.

[0012] Furthermore, the ceramic slurry also includes a photocurable resin and a dispersant, and the ceramic slurry is formed by mixing raw materials including the ceramic particles, the photocurable resin, and the dispersant;

[0013] The mass ratio of the ceramic particles, the photocurable resin, and the dispersant is (40-55):(30-40):(2-5);

[0014] The dispersant includes one or more of Span 20, Tween 80, BYK 103, and Triton 114;

[0015] The photocurable resin includes a first polymeric monomer, a second polymeric monomer, a diluent, and a photoinitiator;

[0016] The mass ratio of the first polymerizing monomer, the second polymerizing monomer, the diluent, and the photoinitiator is (60-70):(10-30):(5-15):(0.1-5).

[0017] The beneficial effect of adopting the above technical solution is that the ceramic matrix blank prepared by 3D printing has a mesh-like pore structure; the second silicon nitride ceramic matrix slurry does not contain a pore-forming agent, which avoids the problem of carbon residue after the pore-forming agent volatilizes in the ceramic matrix, thereby helping to avoid the disordered volatilization of volatiles in the ceramic matrix during sintering, thus avoiding uneven pores on the surface of the ceramic core, and ultimately avoiding the problem of uneven surface of the metal parts prepared by casting with the ceramic core;

[0018] By using ceramic particles, UV-curable resin, and dispersant in a specific mass ratio, and with a low content of UV-curable resin, the problem of high porosity on the surface of the ceramic core after sintering can be avoided.

[0019] By using a ratio of (60-70):(10-30) for the first and second polymeric monomers, good flowability of the ceramic slurry is achieved, and sufficient strength of the silicon nitride ceramic matrix green body is ensured. Furthermore, when the content of the photocurable resin in the ceramic matrix slurry is low, the flowability and dispersion of the second silicon nitride ceramic matrix slurry are not significantly reduced. At the same time, it is beneficial to achieve uniform pore size when the first and second polymeric monomers volatilize during the sintering process, which helps to avoid problems such as difficulty in volatilization and cracks or damage to the ceramic core.

[0020] Furthermore, the mass ratio of silicon nitride to silicon oxide is (1-30):(70-99).

[0021] The beneficial effect of adopting the above technical solution is that by adding silicon nitride, the mass ratio of which to silicon oxide is (1-30):(70-99), the problems of low relative refractive index and easy scattering during 3D printing are solved, while the silicon oxide content in the finished ceramic core reaches more than 99.5%.

[0022] Furthermore, the first polymerizing monomer includes one or more of hydroxyethyl acrylate, hydroxyethyl methacrylate, and hydroxypropyl methacrylate;

[0023] The second monomer includes one or more of pentaerythritol triacrylate, triethylene glycol diacrylate, and 1,6-hexanediol diacrylate;

[0024] The diluent includes n-butanol or isopropanol.

[0025] The beneficial effects of adopting the above technical solution are that the presence of alcohol hydroxyl groups in the chemical formulas of the first and second polymerizing monomers significantly improves the dispersion effect of silicon nitride and silicon oxide in ceramic slurry; the small molecular weight of the first polymerizing monomer results in a fast curing speed during photo-initiated polymerization, and the low molecular weight after polymerization is beneficial for volatilization during subsequent sintering.

[0026] The inclusion of multiple double bond groups in the second polymer monomer is beneficial for improving the strength of the silicon nitride ceramic matrix, which in turn is beneficial for improving the forming accuracy of the ceramic matrix.

[0027] Furthermore, the additive solution includes an additive and a solvent; the additive includes one or more of silica sol, zirconium silicate, zirconium oxide, potassium oxide, and magnesium oxide; the mass fraction of the additive in the additive solution is 30-70%.

[0028] The beneficial effect of adopting the above technical solution is that after the additive solution is impregnated into the ceramic matrix, the silica sol, zirconium silicate, zirconium oxide, potassium oxide, and magnesium oxide in the ceramic additive solution can react with silicon nitride in the ceramic matrix to convert silicon nitride into silicon oxide. At the same time, it is beneficial to improve the surface density of the ceramic core. With an additive solution mass fraction of 30-70%, it is beneficial to impregnate while also achieving high surface density of the ceramic core.

[0029] Furthermore, the specific process of pre-sintering the ceramic substrate is as follows: heating from room temperature to 400-450℃ at a heating rate of 10-14.5℃ / min, and then heating from 400-450℃ to 500-650℃ at a heating rate of 5-7℃ / min; preferably, the temperature is controlled at 50-60℃ during the ceramic slurry process.

[0030] The advantage of adopting the above technical solution is that controlling the temperature of the photocurable resin to 50-60℃ helps to improve the reaction rate during photocuring.

[0031] Raising the temperature from room temperature to 400-450℃ at a rate of 10-14.5℃ / min facilitates the rapid evaporation of dispersants with small molecular weights. Although the molecular weight is small, the pores during evaporation are relatively large and open-pore, which is beneficial for the subsequent evaporation of large molecular weight polymers within these pore sizes. Furthermore, at this temperature, some large molecular weight polymers decompose. Rapid heating helps to decompose large molecular weight polymers without causing them to volatilize, thus avoiding the situation where large molecular weight polymers do not volatilize within the pores created by the volatilization of the original small molecular weight substances. This prevents problems such as closed pores, uneven pore distribution, cracks, or damage. Raising the temperature from 400-450℃ to 500-650℃ at a rate of 5-7℃ / min facilitates the volatilization of large molecular weight polymers within the pores created by the volatilization of the original small molecular weight substances after decomposition.

[0032] Furthermore, the specific process of impregnating the additive solution into the silicon nitride ceramic matrix and then carrying out the heating reaction is as follows:

[0033] The silicon nitride ceramic substrate impregnated with the additive solution is heated in stages in an air atmosphere; the temperature is increased from room temperature to 400-450℃ at a heating rate of 10-14.5℃ / min, and then increased from 400-450℃ to 780-820℃ at a heating rate of 5-7℃ / min, and held at 780-820℃ for 2-4 hours.

[0034] The advantages of adopting the above technical solution are that, by heating from room temperature to 400-450℃ at a heating rate of 10-14.5℃ / min, the moisture impregnated on the surface and inside of the ceramic matrix can be rapidly evaporated, and the additives can be quickly and uniformly adhered to the inside of the ceramic matrix. By heating from 400-450℃ to 780-820℃ at a heating rate of 5-7℃ / min and holding for 2-4 hours, the additives can react with silicon nitride in the ceramic matrix to obtain silicon oxide. At the same time, the nitrogen-containing volatiles generated in the reaction slowly evaporate, thereby avoiding the problem of uneven porosity on the surface of the ceramic matrix caused by the evaporation of nitrogen-containing volatiles.

[0035] Furthermore, the ceramic particles are prepared by granulation of silicon nitride and silicon oxide powders. The specific ceramic particle preparation process is as follows:

[0036] To prepare ceramic particle slurry, silicon nitride powder, silicon oxide powder, solvent, carbon powder, and binder are mixed in a mass ratio of (1-30):(70-99):(100-120):(30-35):(10-15).

[0037] Then, ceramic particle blanks are obtained by spray drying; preferably, the binder includes one or two of polyethylene glycol 200, polyethylene glycol 400, polypropylene glycol 200, and polypropylene glycol 400; the solvent is water.

[0038] Ceramic particles are obtained by heating a ceramic particle blank. The heating process of the ceramic particle blank is as follows: the heat treatment temperature is 300-500℃.

[0039] The beneficial effects of adopting the above technical solution are that the silicon nitride and silicon oxide powder in the ceramic particles are mixed evenly through granulation. Most importantly, it achieves high porosity inside the ceramic particles and low porosity and high density between the ceramic particles. This makes it easy for the ceramic core to break and detach from the metal casting after the molten metal is poured, without damaging the metal casting. In addition, the dense surface of the ceramic core makes the surface of the metal casting smooth.

[0040] Furthermore, the sintering temperature of the ceramic matrix is ​​1050-1150℃.

[0041] The advantage of adopting the above technical solution is that by using a sintering temperature of 1050-1150℃, the ceramic core can meet the strength requirements while facilitating the separation of the core from the metal casting after casting.

[0042] Another aspect of the present invention provides a silica ceramic core, which is prepared according to the method for preparing the silica ceramic core; preferably, the silica ceramic core has a bending strength ≥35MPa and a forming accuracy of 0.05-0.2mm.

[0043] The advantages of this invention over existing technologies lie in the fact that, by including silicon oxide and silicon nitride in the ceramic particles, specifically by introducing silicon nitride, the ceramic slurry achieves a high relative refractive index when used to prepare ceramic matrix green bodies via 3D printing. This significantly reduces scattering during photocuring, thereby achieving a critical exposure energy of ≥178 mJ / cm² for the ceramic slurry. 2 The critical curing thickness is ≤320μm, resulting in high precision in the forming of the ceramic matrix preform; and the silica content in the silica ceramic core is ≥99.5%.

[0044] The dense surface of the silica ceramic core facilitates the production of a smooth casting surface during the casting process. Furthermore, the silica ceramic core is easy to separate from the metal casting after casting, thus avoiding damage to the metal casting caused by the separation of the silica ceramic core from the metal casting. Detailed Implementation

[0045] To better understand the technical solution of the present invention, the present invention will be further described below in conjunction with specific embodiments and the specification.

[0046] Example 1:

[0047] In one aspect of this embodiment, a method for preparing a silicon oxide ceramic core is provided, comprising the following steps:

[0048] A ceramic slurry is prepared, the ceramic slurry comprising ceramic particles, a photocurable resin, and a dispersant; the ceramic particles comprising silica powder and silicon nitride powder.

[0049] The silica powder, silicon nitride powder, photocurable resin, and dispersant are mixed and dispersed evenly in a grinding equipment to obtain the ceramic slurry; the critical exposure energy of the ceramic slurry is 178 mJ / cm. 2 The critical curing thickness is 320μm.

[0050] The mass ratio of the ceramic particles, the photocurable resin, and the dispersant is 48:35:3.5; the dispersant includes Span 20 and Tween 80; the mass ratio of the silicon nitride powder to the silicon oxide powder is 10:90.

[0051] The photocurable resin comprises a first polymeric monomer, a second polymeric monomer, a diluent, and a photoinitiator; the mass ratio of the first polymeric monomer, the second polymeric monomer, the diluent, and the photoinitiator is 65:20:10:2.6.

[0052] The first polymerization monomer includes hydroxyethyl acrylate and hydroxyethyl methacrylate;

[0053] The second monomer comprises pentaerythritol triacrylate and triethylene glycol diacrylate; the diluent comprises n-butanol.

[0054] Based on the ceramic slurry, a ceramic matrix preform is prepared by photopolymerization 3D printing; the ceramic matrix preform is then pre-sintered to obtain the ceramic matrix.

[0055] The specific process of pre-sintering the ceramic substrate is as follows: heating from room temperature to 425°C at a heating rate of 12°C / min, and then heating from 425°C to 575°C at a heating rate of 6°C / min; preferably, the temperature is controlled at 55°C during the ceramic slurry process.

[0056] A solution of additives is prepared, which is then impregnated into a ceramic matrix, followed by a heating reaction.

[0057] The additive solution includes additives and solvents; the additives include silica sol, zirconium silicate, and magnesium oxide; the mass fraction of the additives in the additive solution is 50%.

[0058] The specific process of impregnating the additive solution into the silicon nitride ceramic matrix and then carrying out the heating reaction is as follows: the silicon nitride ceramic matrix impregnated with the additive solution is heated stepwise in an air atmosphere; the temperature is increased from room temperature to 425℃ at a heating rate of 12℃ / min; the temperature is increased from 425℃ to 800℃ at a heating rate of 6℃ / min, and held at that temperature for 3 hours.

[0059] Then, sintering is performed to obtain a silicon oxide ceramic core; the sintering temperature of the ceramic matrix is ​​1100℃.

[0060] In another aspect of this embodiment, a silicon oxide ceramic core is provided, which is prepared according to the method for preparing the silicon oxide ceramic core.

[0061] The prepared ceramic core has a silicon oxide content of 99.9%, a bending strength of 35 MPa, and a forming accuracy of 0.12 mm.

[0062] Example 2:

[0063] The contents that are the same as in Example 1 will not be repeated here; the different aspects of this embodiment compared to Example 1 are as follows:

[0064] In one aspect of this embodiment, a method for preparing a silicon oxide ceramic core is provided, wherein the ceramic particles are prepared by granulation of silicon nitride and silicon oxide powders. Specifically, the ceramic particle preparation process is as follows:

[0065] To prepare a ceramic particle slurry, silicon nitride powder, silicon oxide powder, solvent, carbon powder, and polypropylene glycol 200 are mixed in a mass ratio of 20:80:110:32:12; then, the mixture is spray-dried to obtain a ceramic particle green body; the solvent is water.

[0066] Ceramic particles are obtained by heating a ceramic particle blank, wherein the heating process of the ceramic particle blank is a heat treatment temperature of 400℃.

[0067] The ceramic particles, photocurable resin, and dispersant are mixed and dispersed evenly in a grinding device to obtain the ceramic slurry.

[0068] Critical exposure energy of ceramic slurry: 180 mJ / cm 2 The critical curing thickness is 315μm.

[0069] The mass ratio of the ceramic particles, the light-curing resin, and the dispersant is 53:32:4; the dispersant includes BYK 103 and Triton 114.

[0070] The mass ratio of the first monomer, the second monomer, the diluent, and the photoinitiator is 62:25:13:4;

[0071] The first monomer comprises hydroxypropyl methacrylate; the second monomer comprises triethylene glycol diacrylate and 1,6-hexanediol diacrylate; and the diluent comprises isopropanol.

[0072] The specific process of pre-sintering the ceramic substrate green body is as follows: the temperature is increased from room temperature to 430℃ at a heating rate of 13℃ / min, and then increased from 430℃ to 640℃ at a heating rate of 6.5℃ / min; the temperature is controlled at 58℃ during the ceramic slurry process.

[0073] The additives include silica sol, zirconium oxide, and potassium oxide; the mass fraction of the additives in the additive solution is 60%.

[0074] The silicon nitride ceramic matrix impregnated with the additive solution was distributedly heated in an air atmosphere; the temperature was increased from room temperature to 440℃ at a heating rate of 13.5℃ / min; the temperature was increased from 440℃ to 810℃ at a heating rate of 6.5℃ / min, and held for 2.5 hours; the sintering temperature of the ceramic matrix was 1130℃.

[0075] In another aspect of this embodiment, a silicon oxide ceramic core is provided. The prepared ceramic core has a silicon oxide content of 99.8%, a bending strength of 36 MPa, and a forming accuracy of 0.06 mm.

[0076] Example 3:

[0077] The contents that are the same as in Example 2 will not be repeated here; the differences between this embodiment and Example 2 are as follows:

[0078] In one aspect of this embodiment, a method for preparing a silicon oxide ceramic core is provided, wherein the ceramic particles are prepared by granulation of silicon nitride and silicon oxide powders. Specifically, the ceramic particle preparation process is as follows:

[0079] To prepare a ceramic particle slurry, silicon nitride powder, silicon oxide powder, solvent, carbon powder, and polyethylene glycol 200 are mixed in a mass ratio of 28:72:115:31:11; then, the mixture is spray-dried to obtain a ceramic particle green body.

[0080] Ceramic particles are obtained by heating a ceramic particle blank, wherein the heating process of the ceramic particle blank is a heat treatment temperature of 450℃.

[0081] The ceramic particles, photocurable resin, and dispersant are mixed and dispersed evenly in a grinding device to obtain the ceramic slurry.

[0082] The critical exposure energy of ceramic slurry is 181 mJ / cm. 2 The critical curing thickness is 312 μm.

[0083] The mass ratio of the ceramic particles, the photocurable resin, and the dispersant is 43:38:3; the dispersant includes Tween 80 and BYK 103.

[0084] The mass ratio of the first monomer, the second monomer, the diluent, and the photoinitiator is 78:15:8:1;

[0085] The first polymerization monomer includes hydroxyethyl acrylate and hydroxypropyl methacrylate;

[0086] The second polymerization monomer includes pentaerythritol triacrylate and 1,6-hexanediol diacrylate;

[0087] The specific process of pre-sintering the ceramic matrix green body is as follows: the temperature is increased from room temperature to 410℃ at a heating rate of 11℃ / min, and then increased from 410℃ to 580℃ at a heating rate of 5.5℃ / min.

[0088] The additives include zirconium silicate and magnesium oxide; the mass fraction of the additives in the additive solution is 40%.

[0089] The silicon nitride ceramic matrix impregnated with the additive solution was distributedly heated in air; the temperature was increased from room temperature to 410℃ at a heating rate of 11℃ / min; and then increased from 410℃ to 785℃ at a heating rate of 5.5℃ / min, and held at that temperature for 3.5 hours. The sintering temperature of the ceramic matrix was 1080℃.

[0090] In another aspect of this embodiment, a silicon oxide ceramic core is provided. The prepared ceramic core has a silicon oxide content of up to 99.6%, a bending strength of 37 MPa, and a forming accuracy of 0.1 mm.

[0091] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to the technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, the above-described features have similar functions to (but are not limited to) those disclosed in this application.

Claims

1. A method of producing a silica ceramic core, characterized by, The method comprises the following steps: Preparation of ceramic slurry, the ceramic slurry comprises ceramic particles, the ceramic particles comprise silicon oxide, silicon nitride; Based on the ceramic slurry, a ceramic matrix blank is prepared by light curing 3D printing; The ceramic matrix blank is pre-sintered to obtain a ceramic matrix; Preparation of an auxiliary solution, the auxiliary solution is impregnated into the ceramic matrix, and then a heating reaction is performed; Then sintering is performed to obtain a silicon oxide ceramic core; The auxiliary solution comprises an auxiliary agent and a solvent; the auxiliary agent comprises one or more of silica sol, zirconium silicate, zirconium oxide, potassium oxide and magnesium oxide; the mass fraction of the auxiliary agent in the auxiliary solution is 30-70%; The specific process of impregnating the auxiliary solution into the ceramic matrix and then performing a heating reaction is as follows: The ceramic matrix impregnated with the auxiliary solution is subjected to step-by-step heating in an air atmosphere; the heating rate is 10-14.5 ℃ / min from room temperature to 400-450 ℃, and then the heating rate is 5-7 ℃ / min from 400-450 ℃ to 780-820 ℃; and the temperature is kept at 780-820 ℃ for 2-4 hours.

2. The method of producing a silica ceramic core according to claim 1, characterized by, The ceramic slurry further comprises a light curing resin and a dispersing agent, and the ceramic slurry is prepared by mixing raw materials comprising the ceramic particles, the light curing resin and the dispersing agent; The mass ratio of the ceramic particles, the light curing resin and the dispersing agent is (40-55) : (40-55) : (5-15). (30-40)：(2-5)； The dispersing agent comprises one or more of Span 20, Tween 80, BIK 103 and Triton 114. The light curing resin comprises a first polymerized monomer, a second polymerized monomer, a diluent and a photoinitiator. The mass ratio of the first polymerized monomer, the second polymerized monomer, the diluent and the photoinitiator is (60-70) : (10-30) : (5-15) : (0.1-5).

3. The method of producing a silica ceramic core according to claim 1, characterized by, The mass ratio of the silicon nitride to the silicon oxide is (1-30) : (70-99).

4. The method of producing a silica ceramic core according to claim 2, characterized by, The first polymerized monomer comprises one or more of hydroxyethyl acrylate, hydroxyethyl methacrylate and hydroxypropyl methacrylate. The second polymerized monomer comprises one or more of pentaerythritol triacrylate, triethylene glycol diacrylate and 1,6-hexanediol diacrylate. The diluent comprises n-butanol or isopropyl alcohol.

5. The method of producing a silica ceramic core according to claim 1, wherein The specific process of pre-sintering the ceramic matrix blank is as follows: The heating rate is 10-14.5 ℃ / min from room temperature to 400-450 ℃, and then the heating rate is 5-7 ℃ / min from 400-450 ℃ to 500-650 ℃.

6. The method of producing a silica ceramic core according to claim 1, wherein The ceramic particles are prepared by granulating silicon nitride and silicon oxide powder, and the specific process of preparing the ceramic particles is as follows: Preparation of ceramic particle slurry, the silicon nitride powder, the silicon oxide powder, the solvent, the carbon powder and the binder are mixed in a mass ratio of (1-30) : (70-99) : (100-120) : (30-35) : (10-15); Then the ceramic particle blank is obtained by spray drying; The ceramic particle blank is subjected to heating treatment to obtain the ceramic particles, and the heating treatment process of the ceramic particle blank is that the heat treatment temperature is 300-500 ℃.

7. The method of producing a silica ceramic core according to claim 1, wherein The sintering temperature of the ceramic matrix is 1050-1150 ℃.

8. A silica ceramic core, characterized by, The silica ceramic core is prepared according to the method of any one of claims 1-7.