CN118163212A - A method for preparing a double-wall cold ceramic core by additive-isotropic material collaboration - Google Patents

Abstract

The invention relates to a method for preparing a double-wall cold ceramic core by additive-isowood cooperation, which comprises the following steps: preparing a resin mold by adopting a photocuring 3D printing method; the resin mold is used for forming a hollow structure of the double-wall cold ceramic core; preparing a support body by adopting a photocuring 3D printing method; the support body is used for forming a framework of a first wall on the double-wall cold ceramic core after degreasing treatment, and the first wall is a wall with the thickness of more than 5 mm; assembling a resin mold and a support body in the outline mold; then, injecting the ceramic core slurry into a profile die for hot-press injection molding to form a ceramic biscuit; and (3) degreasing and sintering the ceramic biscuit in sequence to obtain the double-wall cold ceramic core. The invention realizes high-precision integrated molding of the double-wall cold ceramic core by utilizing an additive-equivalent material synergistic mode, and has the advantages of obviously reduced number of dies, obviously shortened preparation period and obviously reduced cost.

Description

A method for preparing a double-wall cold ceramic core by additive-isotropic synergistically

Technical Field

The invention relates to the technical field of precision casting of key aviation parts, and in particular to a method for preparing a double-wall cold ceramic core in a collaborative manner of additive and isotropic materials.

Background technique

The development of advanced aircraft engine manufacturing technology is an important scientific and technological highland for countries around the world to ensure national security. Among them, the high-pressure turbine blades are the components with the most demanding working environment in aircraft engines. Therefore, the optimization of the preparation process and cooling structure of high-pressure turbine blades has become a top priority for achieving high-performance aircraft engines. With the increasing temperature of the air inlet of advanced power systems used in major equipment such as aircraft engines, the preparation of efficiently cooled single-crystal high-temperature alloy blades has become an inevitable development trend for future advanced aircraft engines, and the preparation and use of double-walled cooled single-crystal high-temperature alloy blades has become an effective solution to improve the combustion efficiency of aircraft engines.

Ceramic core is a key transition component for forming the complex internal cooling channels of double-walled cooled turbine blades during precision casting. The preparation technology of double-walled cooled ceramic core has become a key technical problem that needs to be solved urgently to improve the combustion efficiency of aircraft engines.

In order to achieve efficient and high-precision preparation of double-wall cold ceramic cores, the main research process at present is to prepare double-wall cold ceramic cores by hot pressing and parting with multiple sets of metal molds and then assembling them together. However, this process has problems such as long preparation cycle, high mold design and preparation costs, large assembly errors, and low core yield. Therefore, it is urgent to find a process solution that reduces the number of molds and can achieve integrated molding of double-wall cold ceramic cores.

Summary of the invention

In view of this, the present invention provides a method for preparing a double-walled cold ceramic core by additive and isotropic materials, the main purpose of which is to achieve one-piece molding of the double-walled cold ceramic core, reduce the number of molds, and avoid the problem of large assembly errors.

In order to achieve the above object, the present invention mainly provides the following technical solutions:

On the one hand, an embodiment of the present invention provides a method for preparing a double-walled cold ceramic core by additive-isotropic material synergistically, which comprises the following steps:

A resin mold is prepared by using a photo-curing 3D printing method; the resin mold is used to form a hollow structure of a double-walled cold ceramic core;

Prepare a support body by using a photo-curing 3D printing method; the support body is used to form a skeleton of a first wall on a double-wall cold ceramic core after degreasing, and the first wall is a wall with a thickness greater than 5 mm;

Hot-pressing molding step: assembling the resin mold and the support body in the outer mold; then, injecting the ceramic core slurry into the outer mold for hot-pressing molding to form a ceramic blank;

Degreasing and sintering treatment steps: the ceramic blank is subjected to degreasing treatment and sintering treatment in sequence to obtain a double-wall cold ceramic core.

Preferably, in the step of preparing the resin mold: the photocurable molding resin is subjected to photocuring 3D printing to obtain a resin mold; wherein, in parts by weight, the photocurable molding resin includes 45-55 parts by weight of a viscosity modifier, 25-35 parts by weight of a cross-linking agent, and 5-15 parts by weight of a cross-linking initiator; preferably, the viscosity modifier, the cross-linking agent, and the cross-linking initiator are stirred at a temperature of 40-80°C for 60-360 minutes to obtain the photocurable molding resin.

Preferably, the viscosity modifier is one or more of isobornyl acrylate, ethoxylated oxyphenyl acrylate, and octadecyl acrylate; and/or the cross-linking agent is one or more of tricyclodecyl dimethanol diacrylate, propoxylated neopentyl glycol diacrylate, dipropylene glycol diacrylate, and tripropylene glycol diacrylate; and/or the cross-linking initiator is one or more of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2-hydroxy-2-methyl-1-phenylacetone-1, and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide; and/or the molecular weight of the viscosity modifier is 150-240; and/or the molecular weight of the cross-linking agent is 240-350.

Preferably, in the step of preparing the support body: the photocurable ceramic slurry is subjected to photocuring 3D printing treatment to obtain the support body; wherein, in parts by weight, the photocurable ceramic slurry includes: 25-35 parts by weight of a supporting agent, 10-20 parts by weight of a fixing agent, 5-15 parts by weight of a filler, 3-10 parts by weight of a toughening agent, 15-20 parts by weight of a crosslinking agent, 10-15 parts by weight of a shrinkage reducing agent, 2-5 parts by weight of a crosslinking initiator, and 2-5 parts by weight of a dispersant.

Preferably, in the step of preparing the support body: the supporting agent, fixing agent, filler and toughening agent are stirred and mixed for 30-90 minutes to obtain a mixed powder; after adding a shrinkage reducing agent and a crosslinking initiator to the crosslinking agent, the mixture is stirred at a temperature of 60-120°C for 30-90 minutes, and then the mixed powder is added thereto and stirred for 120-360 minutes; during the stirring process, a dispersant is added in batches, and after stirring, a light-cured ceramic slurry is obtained.

Preferably, the support agent is one or both of alumina and silica; and/or the fixing agent is one or both of zircon powder and silica; and/or the filler is one or both of zircon powder and silica; and/or the toughening agent is one or more of mullite fiber, quartz fiber and alumina fiber; and/or the cross-linking agent is ethoxylated trimethylolpropane triacrylate, propoxylated glycerol triacrylate, alkoxylated pentaerythritol tetraacrylate, dimethylolpropane tetraacrylate. One or more of acrylates; and/or the shrinkage reducing agent is one or more of polyborosilazane, polysilicone carbodiimide, and polysilsesquioxane; and/or the crosslinking agent initiator is one or more of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2-hydroxy-2-methyl-1-phenylacetone-1, and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide; and/or the dispersant is one or more of BYK-9076, BYK111, and KOS110.

Preferably, the molecular weight of the cross-linking agent is 400-500; and/or the particle size of the supporting agent is 25-75 μm; and/or the particle size of the fixing agent is 1-5 μm; and/or the particle size of the filler is 0.1-0.5 μm; and/or the diameter of the toughening agent is 10-200 nm and the length is 200-400 μm.

Preferably, in the hot injection molding step: in terms of weight percentage, the ceramic core slurry comprises 20-30% paraffin wax and 70-80% ceramic powder; preferably, the paraffin wax and ceramic powder are stirred at a temperature of 120-180°C to obtain a ceramic core slurry; preferably, the ceramic powder is silica ceramic powder; preferably, the particle size of the silica ceramic powder is 1-25 μm; and/or the parameters of the hot injection molding are set as follows: the injection temperature is 80-150°C, the mold temperature is 50-100°C, the injection pressure is 3.5-5.5Mpa, the injection time is 60-90s, and the holding time is 60-180s.

Preferably, in the degreasing and sintering steps:

The degreasing treatment comprises: heating the ceramic blank to 150-300°C at a first heating rate and keeping the temperature for 120-180 minutes; then, heating the blank to 300-400°C at a second heating rate and keeping the temperature for 60-360 minutes; then, heating the blank to 500-700°C at a third heating rate and keeping the temperature for 180-360 minutes, and then cooling the blank to room temperature at a first cooling rate to obtain a degreasing ceramic blank; preferably, the atmosphere of the degreasing treatment is air; preferably, the first heating rate is 1-3°C/min, the second heating rate is 1-2°C/min, the third heating rate is 2-5°C/min, and the first cooling rate is 1-5°C/min; and/or

The sintering process comprises: heating the degreased ceramic blank to 1000-1400°C at a fourth heating rate, keeping the temperature for 240-360 minutes, and then cooling at a second cooling rate to obtain a double-wall cold ceramic core; preferably, the sintering atmosphere is air; preferably, the fourth heating rate is 5-8°C/min; and the second cooling rate is 5-8°C/min.

On the other hand, an embodiment of the present invention provides a double-wall cold ceramic core, wherein the double-wall cold ceramic core is prepared by the preparation method of the double-wall cold ceramic core described in any one of the above items; preferably, the double-wall cold ceramic core includes a first wall with a thickness greater than 5 mm and a second wall with a thickness less than 1 mm; the double-wall cold ceramic core has a hollow structure; preferably, the hollow structure includes a gap. Here, the first wall and the second wall of the double-wall cold ceramic core of the present invention are integrally formed, non-deformed, high in precision, and the connecting portion between the first wall and the second wall is not easy to crack.

Compared with the prior art, the method of the present invention for preparing a double-walled cold ceramic core by additive-isotropic material collaboration has at least the following beneficial effects:

The embodiment of the present invention proposes a method for preparing a double-walled cold ceramic core by additive-isotropic materials, which mainly includes the following steps: the present invention first prepares a resin mold and a support body respectively by photocuring 3D printing technology; then, the resin mold and the support body are assembled in an outer metal mold, and the ceramic core slurry is injected into the outer metal mold, and hot injection molding is performed to obtain a ceramic blank wrapped with the resin mold and the support body. Finally, the ceramic blank is degreased and sintered; wherein, during the degreasing and sintering process, the resin mold is removed; and the resin part of the support body is removed to form a skeleton of the thick-walled area (first wall). It should be noted here that: the present application proposes for the first time to utilize photocuring to form a synergistic reinforcement of the resin mold and the support body, thereby avoiding the deformation of the double-walled cold ceramic core during the hot injection molding process, improving the high-precision molding of the layer-cold fine structure, and improving the deformation and cracking caused by the sintering shrinkage difference between the thick-walled area and the thin-walled area of the double-walled cold ceramic core. Specifically, the support body forms a skeleton as the thick part (first wall) on the double-walled cold ceramic core, so that when the ceramic core is subsequently hot-pressed and molded, the outer skin of the thick part skeleton is relatively thin, and is formed simultaneously with the thin wall of the ceramic core. Since the thickness difference is not large, the shrinkage is also the same during the degreasing and sintering treatment, thereby avoiding deformation and cracking problems caused by thickness differences. In addition, the above scheme of the present invention greatly reduces the number of molds in the hot-pressing and parting preparation process of the double-walled cold ceramic core that is generally applicable at this stage, and realizes the integrated removal of the resin mold, the paraffin of the core blank, and the resin in the support body, shortening the preparation cycle and reducing the preparation cost. The one-piece molding method significantly eliminates the error caused by the core assembly and significantly improves the accuracy of the core.

Furthermore, an embodiment of the present invention provides a method for preparing a double-wall cold ceramic core by additive-equal materials, and each formula component and preparation process has a synergistic effect. For example, the molecular weight of the photosensitive resin (cross-linking agent) used in the resin mold does not exceed 350, and the decomposition temperature of this type of resin is generally lower than 300°C. The molecular weight of the photosensitive resin (cross-linking agent) used in the support body is not lower than 400, and the decomposition temperature is about 500-700°C, while the decomposition temperature of the paraffin used for hot pressing is between the two. Through the designed degreasing heating rate and three-stage insulation, the sequential removal of the resin mold-paraffin in the hot pressing core blank-resin in the light-curing molding support body can be achieved, avoiding cracking and deformation caused by degreasing and flatulence. For example, the powder particle size and composition design of the support body can prevent it from shrinking during the sintering process, avoiding separation and cracking from the outer skin of the hot-pressed core on the outer side, thereby supporting the thick wall area of the double-wall cold ceramic core. In addition, the supporting agent plays the role of skeleton; the fixing agent plays the role of fixing and bonding the skeleton; the filler plays the role of strengthening the skeleton and adjusting the porosity; the toughening agent plays the role of toughening the support body; the cross-linking agent plays the role of 3D printing curing and cross-linking; the shrinkage reducing agent plays the role of controlling and reducing the sintering shrinkage of the support body; the cross-linking initiator plays the role of assisting cross-linking and curing; and the dispersant plays the role of ensuring the uniform dispersion of the slurry.

The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a flow chart of a preparation method of a double-walled cold ceramic core provided by an embodiment of the present invention;

FIG. 2 is a physical picture of a double-walled cold ceramic core prepared in Example 1 of the present invention.

Detailed ways

In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation methods, structures, features and effects of the present invention application are described in detail below in conjunction with the accompanying drawings and preferred embodiments. In the following description, different "one embodiment" or "embodiment" does not necessarily refer to the same embodiment. In addition, specific features, structures, or characteristics in one or more embodiments may be combined in any suitable form.

The design concept of the present invention is as follows: the present invention utilizes photocuring 3D printing technology, first prefabricates a resin mold through photocuring resin, and then prepares a support body of a thick-walled area of a double-walled cold ceramic core through photocuring 3D printing technology, and installs the resin mold and the support body in a metal shape mold through cooperation, and finally prepares a ceramic blank wrapped with the resin mold and the support body through hot injection molding. Finally, the ceramic blank wrapped with the resin mold and the support body is degreased and sintered (in this process, the resin mold can be removed, and the resin component in the support body can be removed to form a supporting skeleton). This process scheme not only solves the forming problem of the complex layer cold structure of the double-walled cold ceramic core, but also solves the problem of insufficient strength of the resin mold during hot pressing. The present invention controls the molecular weight of the photosensitive resin and combines the degreasing process to realize the sequential removal of the resin in the resin mold-the paraffin in the injection core blank-the photocuring support body, prevents the formation of removal cracking defects, and realizes efficient and low-cost one-piece molding of double-walled cold ceramic core products.

On the one hand, an embodiment of the present invention provides a method for preparing a double-walled cold ceramic core by additive-isotropic material synergistically, which comprises the following steps:

A resin mold is prepared by adopting a light-curing 3D printing method; the resin mold is used to form a hollow structure of a double-wall cold ceramic core.

In this step: a photocurable molding resin is subjected to a photocurable 3D printing process to obtain a resin mold; wherein, in parts by weight, the photocurable molding resin includes 45-55 parts by weight of a viscosity modifier, 25-35 parts by weight of a crosslinking agent, and 5-15 parts by weight of a crosslinking initiator.

Preferably, the viscosity modifier, the crosslinking agent and the crosslinking initiator are stirred at a temperature of 40-80° C. for 60-360 minutes to obtain the light-curable molding resin.

The viscosity modifier is one or more of isobornyl acrylate, ethoxylated oxyphenyl acrylate, and octadecyl acrylate. The crosslinking agent is one or more of tricyclodecyl dimethanol diacrylate, propoxylated neopentyl glycol diacrylate, dipropylene glycol diacrylate, and tripropylene glycol diacrylate. The molecular weight of the viscosity modifier is 150-240. The molecular weight of the crosslinking agent is 240-350. The crosslinking initiator is one or more of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2-hydroxy-2-methyl-1-phenylacetone-1, and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide.

A support body is prepared by using a photo-curing 3D printing method; the support body is used to form a skeleton of a first wall on a double-wall cold ceramic core after degreasing, and the first wall is a wall with a thickness greater than 5 mm.

Wherein, in this step: the photocurable ceramic slurry is subjected to photocuring 3D printing treatment to obtain a support body; wherein, in parts by weight, the photocurable ceramic slurry includes: 25-35 parts by weight of a supporting agent, 10-20 parts by weight of a fixing agent, 5-15 parts by weight of a filler, 3-10 parts by weight of a toughening agent, 15-20 parts by weight of a crosslinking agent, 10-15 parts by weight of a shrinkage reducing agent, 2-5 parts by weight of a crosslinking initiator, and 2-5 parts by weight of a dispersant.

The supporting agent, fixing agent, filler and toughening agent are stirred and mixed for 30-90 minutes to obtain a mixed powder; after adding a shrinkage reducing agent and a crosslinking initiator to the crosslinking agent, the mixture is stirred at a temperature of 60-120° C. for 30-90 minutes, and then the mixed powder is added thereto and stirred for 120-360 minutes; during the stirring process, a dispersant is added in batches, and after stirring, a light-cured ceramic slurry is obtained.

Wherein, the supporting agent is one or two of alumina and silica; and/or the fixing agent is one or two of zircon powder and silica; and/or the filler is one or two of zircon powder and silica; and/or the toughening agent is one or more of mullite fiber, quartz fiber and alumina fiber; and/or the cross-linking agent is ethoxylated trimethylolpropane triacrylate, propoxylated glycerol triacrylate, alkoxylated pentaerythritol tetraacrylate, dimethylolpropane tetraacrylate One or more of acrylates; and/or the shrinkage reducing agent is one or more of polyborosilazane, polysilicone carbodiimide, and polysilsesquioxane; and/or the crosslinking agent initiator is one or more of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2-hydroxy-2-methyl-1-phenylacetone-1, and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide; and/or the dispersant is one or more of BYK-9076, BYK111, and KOS110.

Wherein, the molecular weight of the cross-linking agent is 400-500; and/or the particle size of the supporting agent is 25-75 μm; and/or the particle size of the fixing agent is 1-5 μm; and/or the particle size of the filler is 0.1-0.5 μm; and/or the diameter of the toughening agent is 10-200 nm and the length is 200-400 μm.

Hot-pressing molding step: assembling the resin mold and the support body in the outer mold; then, injecting the ceramic core slurry into the outer mold for hot-pressing molding to form a ceramic blank.

The ceramic core slurry comprises paraffin wax and silicon dioxide ceramic powder; preferably, the paraffin wax and silicon dioxide ceramic powder are stirred at a temperature of 120-180°C to obtain the ceramic core slurry. The silicon dioxide ceramic powder is silicon dioxide, or the main component of the silicon dioxide ceramic powder is silicon dioxide, and preferably conventional additives (the main components of the additives are Al ₂ O ₃ and ZrSiO ₄ ) are also contained.

Degreasing and sintering treatment steps: the ceramic blank is subjected to degreasing treatment and sintering treatment in sequence to obtain a double-wall cold ceramic core.

The degreasing treatment comprises: heating the ceramic blank to 150-300°C at a first heating rate and keeping the temperature for 120-180 minutes; then, heating the blank to 300-400°C at a second heating rate and keeping the temperature for 60-360 minutes; subsequently, heating the blank to 500-700°C at a third heating rate and keeping the temperature for 180-360 minutes, and then cooling the blank to room temperature at a first cooling rate to obtain a degreasing ceramic blank; preferably, the atmosphere for the degreasing treatment is air; preferably, the first heating rate is 1-3°C/min, the second heating rate is 1-2°C/min, the third heating rate is 2-5°C/min, and the first cooling rate is 1-5°C/min.

The sintering process comprises: heating the degreased ceramic blank to 1000-1400°C at a fourth heating rate, keeping the temperature for 240-360 minutes, and then cooling at a second cooling rate to obtain a hot-pressed double-wall cold ceramic core; preferably, the sintering atmosphere is air; preferably, the fourth heating rate is 5-8°C/min; and the second cooling rate is 5-8°C/min.

On the other hand, an embodiment of the present invention provides a double-wall cold ceramic core, wherein the double-wall cold ceramic core is prepared by the preparation method of the hot injection double-wall cold ceramic core described in any one of the above items; preferably, the double-wall cold ceramic core comprises a first wall with a thickness greater than 5 mm and a second wall with a thickness less than 1 mm. The double-wall cold ceramic core has a hollow structure; the hollow structure comprises a void (see void 3 in FIG. 2 , which is formed by half-enclosing the first wall 1 and/or the second wall 2).

What needs to be explained about the above-mentioned scheme of the present invention is:

(1) The embodiment of the present invention provides a method for preparing a double-walled cold ceramic core by additive-isotropic materials. It proposes for the first time to use the synergistic reinforcement of the photocuring resin mold and the support body to avoid deformation of the double-walled cold ceramic core during hot injection molding, improve the high-precision molding of the layered cold fine structure, and improve the deformation and cracking caused by the sintering shrinkage difference between the thick wall area and the thin wall area of the double-walled cold ceramic core. Specifically, the support body forms the skeleton of the thick part (first wall) on the double-walled cold ceramic core, so that during the subsequent hot injection molding of the ceramic core, the outer skin of the thick part skeleton is relatively thin and is formed at the same time as the thin wall of the ceramic core. Since the thickness difference is not large, the shrinkage is also the same during the degreasing and sintering process, thereby avoiding the deformation and cracking problems caused by the thickness difference.

(2) The embodiment of the present invention provides a method for preparing a double-walled cold ceramic core by additive-isotropic materials, which greatly reduces the number of molds in the hot pressing and parting molding process for preparing double-walled cold ceramic cores that is currently commonly used, and realizes the integrated removal of the wax in the resin mold, the core blank, and the resin in the support body, shortening the preparation cycle and reducing the preparation cost. The integrated molding method significantly eliminates the error caused by the core assembly and significantly improves the accuracy of the core.

(3) The embodiment of the present invention provides a method for preparing a double-wall cold ceramic core by additive-isotropic materials, and each formula component and preparation process has a synergistic effect. For example, the molecular weight of the photosensitive resin used in the resin mold is not more than 350, and the decomposition temperature of this type of resin is generally lower than 300°C. The molecular weight of the photosensitive resin used in the support body is not less than 400, and the decomposition temperature is about 500-700°C, while the decomposition temperature of the paraffin used for hot pressing is between the two. Through the designed degreasing heating rate and three-stage insulation, the sequential removal of the resin mold-hot pressing core blank-photocuring molding support body can be achieved, avoiding cracking and deformation caused by degreasing and swelling. For example, the powder particle size and composition design of the support body can prevent it from shrinking during the sintering process, avoiding separation and cracking from the outer skin of the hot pressing core on the outer side, thereby supporting the thick wall area of the double-wall cold ceramic core.

The present invention is further described below by means of specific experimental examples:

Example 1

This embodiment provides a method for preparing a double-walled cold ceramic core by additive-isotropic material collaboration, which mainly includes the following steps:

A resin mold was prepared, and a viscosity modifier, a cross-linking agent, and a cross-linking initiator were mechanically stirred at a temperature of 60° C. for 120 minutes to obtain a light-cured molding resin. A double-wall cold ceramic core resin mold was prepared from the light-cured molding resin using a light-cured 3D printing device.

Among them, the viscosity modifier is 55 parts by weight, the crosslinking agent is 35 parts by weight, and the crosslinking initiator is 10 parts by weight. Among them, the viscosity modifier is isobornyl acrylate with a molecular weight of 208. The crosslinking agent is a mixture of tricyclodecyl dimethanol diacrylate with a molecular weight of 304 and propoxylated neopentyl glycol diacrylate with a molecular weight of 328 in a mass ratio of 3:1. The crosslinking initiator is 2,4,6-trimethylbenzoyl-diphenylphosphine oxide.

A support body is prepared by using a photo-curing 3D printing method; the support body is used to form a skeleton of a first wall on a double-wall cold ceramic core after degreasing, and the first wall is a wall with a thickness greater than 5 mm.

In this step, the supporting agent, fixing agent, filler and toughening agent are mechanically stirred for 60 minutes to obtain a mixed powder; after adding a shrinkage reducing agent and a cross-linking initiator to the cross-linking agent and stirring at 90°C for 90 minutes, the mixed powder is added thereto and mechanically stirred for 120 minutes. During the stirring process, dispersants are successively added to prepare a light-cured ceramic slurry, and a double-walled cold ceramic core support body is cured and formed using a light-curing 3D printing device.

Among them, there are 35 parts by weight of supporting agent, 15 parts by weight of fixing agent, 5 parts by weight of filler, 10 parts by weight of toughening agent, 15 parts by weight of crosslinking agent, 10 parts by weight of shrinkage reducing agent, 5 parts by weight of crosslinking initiator and 5 parts by weight of dispersant.

Among them, the supporting agent is silica with a particle size of 45μm; the fixing agent is zircon powder with a particle size of 1μm; the filler is zircon powder with a particle size of 0.5μm; the toughening agent is mullite fiber with a diameter of 100nm and a length of 200μm; the cross-linking agent is ethoxylated trimethylolpropane triacrylate with a molecular weight of 428; the shrinkage reducing agent is polyborosilazane; the cross-linking initiator is 2-hydroxy-2-methyl-1-phenylacetone-1; the dispersant is a mixed solution of BYK-9076 and BYK111 (the volume ratio of BYK-9076 and BYK111 is 1:1).

Hot-pressing molding step: assembling the resin mold and the support body in the outer mold; then, injecting the ceramic core slurry into the outer mold for hot-pressing molding to form a ceramic blank.

The resin molding mold and the support body are assembled and installed in the outer metal mold for double-wall cold ceramic core molding for standby use. The ceramic core slurry is injected into the outer metal mold with the resin mold and the support body installed inside by hot injection equipment to obtain a ceramic blank with the resin mold wrapped by the ceramic slurry. The injection temperature is 100°C, the mold temperature is 80°C, the injection pressure is 3.5Mpa, the injection time is 90s, and the holding time is 180s.

The preparation steps of the ceramic core slurry are as follows: paraffin wax and silicon dioxide ceramic powder are stirred at a temperature of 160° C. to obtain the ceramic core slurry. In the ceramic core slurry, the mass proportion of paraffin wax is 20%, the mass proportion of silicon dioxide ceramic powder is 80%, the silicon dioxide ceramic powder is SiO ₂ , and the particle size of the silicon dioxide ceramic powder is 1 micron.

Degreasing and sintering treatment steps: the ceramic blank is subjected to degreasing treatment and sintering treatment in sequence to obtain a double-wall cold ceramic core.

The degreasing treatment is as follows: the ceramic green body is heated to 200°C in air at a heating rate of 1°C/min, and kept warm for 120 minutes; then heated to 350°C at a heating rate of 2°C/min, and kept warm for 60 minutes; then heated to 600°C at a heating rate of 4°C/min, and kept warm for 180 minutes; finally, cooled to room temperature at a heating rate of 3°C/min.

The sintering parameters are as follows: in air, the degreased ceramic blank is heated to 1200°C at a heating rate of 5°C/min, kept at this temperature for 360 minutes, and then cooled at a cooling rate of 5°C/min to obtain a double-walled cold ceramic core.

The actual picture of the double-wall cold ceramic core prepared in this embodiment is shown in Figure 2. As shown in Figure 2, the double-wall cold ceramic core includes a first wall 1 with a thickness greater than 5 mm and a second wall 2 with a thickness less than 1 mm. The double-wall cold ceramic core has a hollow structure; the hollow structure includes a gap 3, which is formed by half-enclosing the first wall 1 and/or the second wall 2.

Example 2

This embodiment provides a method for preparing a double-walled cold ceramic core by additive-isotropic material collaboration, which mainly includes the following steps:

A resin mold was prepared, and a viscosity modifier, a cross-linking agent, and a cross-linking initiator were mechanically stirred at a temperature of 80° C. for 60 minutes to obtain a light-cured molding resin. A double-wall cold ceramic core resin mold was prepared from the light-cured molding resin using a light-cured 3D printing device.

Among them, the viscosity modifier is 50 parts by weight, the crosslinking agent is 35 parts by weight, and the crosslinking initiator is 15 parts by weight. Among them, the viscosity modifier is ethoxylated oxyphenyl acrylate with a molecular weight of 236. The crosslinking agent is a mixture of dipropylene glycol diacrylate with a molecular weight of 242 and tripropylene glycol diacrylate with a molecular weight of 300 in a mass ratio of 4:3. The crosslinking initiator is bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide.

A support body is prepared by using a photo-curing 3D printing method; the support body is used to form a skeleton of a first wall on a double-wall cold ceramic core after degreasing, and the first wall is a wall with a thickness greater than 5 mm.

In this step, the supporting agent, fixing agent, filler and toughening agent are mechanically stirred for 90 minutes to obtain a mixed powder. After adding a shrinkage reducing agent and a crosslinking initiator to the crosslinking agent and stirring at 120°C for 30 minutes, the mixed powder is added thereto and mechanically stirred for 180 minutes. During the stirring process, a dispersant is added successively to prepare a light-cured ceramic slurry, and a double-walled cold ceramic core support is cured and formed using a light-curing 3D printing device.

Among them, there are 25 parts by weight of supporting agent, 20 parts by weight of fixing agent, 10 parts by weight of filler, 10 parts by weight of toughening agent, 20 parts by weight of crosslinking agent, 15 parts by weight of shrinkage reducing agent, 2 parts by weight of crosslinking initiator and 3 parts by weight of dispersant.

Among them, the supporting agent is alumina with a particle size of 75μm; the fixing agent is silica powder with a particle size of 5μm; the filler is silica powder with a particle size of 0.1μm; the toughening agent is alumina fiber with a diameter of 10nm and a length of 300μm; the cross-linking agent is dimethylolpropane tetraacrylate with a molecular weight of 438; the shrinkage reducing agent is polysilicon carbodiimide; the cross-linking agent initiator is bis(2,4,6-trimethylbenzoyl); and the dispersant is KOS110.

Hot injection molding step: assemble the resin mold and the support body in the outer mold; then, inject the ceramic core slurry into the outer mold for hot injection molding to form a ceramic blank. The injection temperature is 80°C, the mold temperature is 70°C, the injection pressure is 4Mpa, the injection time is 80s, and the holding time is 100s.

The resin forming mold and the support body are assembled and installed in the outer metal mold for double-wall cold ceramic core forming for standby use. The ceramic core slurry is injected into the outer metal mold with the resin mold and the support body installed inside by hot injection equipment to obtain a ceramic blank with the resin mold wrapped by the ceramic slurry.

The paraffin wax and silicon dioxide ceramic powder are stirred at a temperature of 180° C. to obtain a ceramic core slurry. In the ceramic core slurry, the mass fraction of the paraffin wax is 25%, and the mass fraction of the silicon dioxide ceramic powder is 75%. The silicon dioxide ceramic powder is SiO ₂ . The particle size of the silicon dioxide ceramic powder is 25 microns.

Degreasing and sintering treatment steps: the ceramic blank is subjected to degreasing treatment and sintering treatment in sequence to obtain a double-wall cold ceramic core.

The degreasing treatment is as follows: the ceramic green body is heated to 300°C at a heating rate of 3°C/min in air, and kept warm for 180 minutes; then heated to 400°C at a heating rate of 2°C/min, and kept warm for 180 minutes; then heated to 700°C at a heating rate of 5°C/min, and kept warm for 300 minutes; finally, cooled to room temperature at a cooling rate of 1°C/min.

The sintering parameters are as follows: in air, the degreased ceramic blank is heated to 1400°C at a heating rate of 8°C/min, kept at that temperature for 300 minutes, and then cooled at a cooling rate of 8°C/min to obtain a double-walled cold ceramic core.

Example 3

This embodiment provides a method for preparing a double-walled cold ceramic core by additive-isotropic material collaboration, which mainly includes the following steps:

A resin mold was prepared, and a viscosity modifier, a cross-linking agent, and a cross-linking initiator were mechanically stirred at a temperature of 60° C. for 300 minutes to obtain a light-cured molding resin. A double-wall cold ceramic core resin mold was prepared from the light-cured molding resin using a light-cured 3D printing device.

Among them, the viscosity modifier is 55 parts by weight, the crosslinking agent is 35 parts by weight, and the crosslinking initiator is 10 parts by weight. Among them, the viscosity modifier is octadecyl acrylate with a molecular weight of 215. The crosslinking agent is a mixture of tricyclodecyl dimethanol diacrylate with a molecular weight of 304 and dipropylene glycol diacrylate with a molecular weight of 242 in a mass ratio of 4:1. The crosslinking initiator is 2,4,6-trimethylbenzoyl-diphenylphosphine oxide.

A support body is prepared by using a photo-curing 3D printing method; the support body is used to form a skeleton of a first wall on a double-wall cold ceramic core after degreasing, and the first wall is a wall with a thickness greater than 5 mm.

In this step, the supporting agent, fixing agent, filler and toughening agent are mechanically stirred for 60 minutes to obtain a mixed powder. After adding a shrinkage reducing agent and a crosslinking initiator to the crosslinking agent and stirring at 100°C for 60 minutes, the mixed powder is added thereto and mechanically stirred for 140 minutes. During the stirring process, a dispersant is added successively to prepare a light-cured ceramic slurry, and a double-walled cold ceramic core support is cured and formed using a light-curing 3D printing device.

Among them, there are 35 parts by weight of supporting agent, 10 parts by weight of fixing agent, 10 parts by weight of filling agent, 5 parts by weight of toughening agent, 20 parts by weight of crosslinking agent, 10 parts by weight of shrinkage reducing agent, 5 parts by weight of crosslinking initiator and 5 parts by weight of dispersant.

Among them, the supporting agent is alumina with a particle size of 55μm; the fixing agent is silica powder with a particle size of 4μm; the filler is silica powder with a particle size of 0.5μm; the toughening agent is alumina fiber with a diameter of 100nm and a length of 200μm; the cross-linking agent is propoxylated glycerol triacrylate with a molecular weight of 454; the shrinkage reducing agent is polyborosilazane; the cross-linking agent initiator is 2,4,6-trimethylbenzoyl-diphenylphosphine oxide; and the dispersant is BYK-9076.

Hot injection molding step: assemble the resin mold and the support body in the outer mold; then, inject the ceramic core slurry into the outer mold for hot injection molding to form a ceramic blank. The injection temperature is 120°C, the mold temperature is 80°C, the injection pressure is 5Mpa, the injection time is 90s, and the holding time is 120s.

The resin forming mold and the support body are assembled and installed in the outer metal mold for double-wall cold ceramic core forming for standby use. The ceramic core slurry is injected into the outer metal mold with the resin mold and the support body installed inside by hot injection equipment to obtain a ceramic blank with the resin mold wrapped by the ceramic slurry.

The paraffin wax and silicon dioxide ceramic powder are stirred at a temperature of 120°C to obtain a ceramic core slurry; wherein, in the ceramic core slurry, the mass fraction of the paraffin wax is 27%, and the mass fraction of the silicon dioxide ceramic powder is 73%; the component of the silicon dioxide ceramic powder is silicon dioxide. The particle size of the silicon dioxide ceramic powder is 10 microns.

Degreasing and sintering treatment steps: the ceramic blank is subjected to degreasing treatment and sintering treatment in sequence to obtain a double-wall cold ceramic core.

The degreasing treatment is as follows: the ceramic green body is heated to 280°C in air at a heating rate of 1°C/min, and kept warm for 160 minutes; then heated to 350°C at a heating rate of 2°C/min, and kept warm for 360 minutes; then heated to 600°C at a heating rate of 4°C/min, and kept warm for 360 minutes; finally, cooled to room temperature at a cooling rate of 5°C/min.

The sintering parameters are as follows: in air, the degreased ceramic blank is heated to 1200°C at a heating rate of 5°C/min, kept at this temperature for 360 minutes, and then cooled at a cooling rate of 6°C/min to obtain a double-walled cold ceramic core.

Example 4

This embodiment provides a method for preparing a double-walled cold ceramic core by additive-isotropic material collaboration, which mainly includes the following steps:

A resin mold was prepared, and a viscosity modifier, a cross-linking agent, and a cross-linking initiator were mechanically stirred at a temperature of 40° C. for 360 minutes to obtain a light-cured molding resin. A double-wall cold ceramic core resin mold was prepared from the light-cured molding resin using a light-cured 3D printing device.

Among them, the viscosity modifier is 50 parts by weight, the crosslinking agent is 35 parts by weight, and the crosslinking initiator is 15 parts by weight. Among them, the viscosity modifier is isobornyl acrylate with a molecular weight of 208. The crosslinking agent is a mixture of propoxylated neopentyl glycol diacrylate with a molecular weight of 328 and tripropylene glycol diacrylate with a molecular weight of 300 in a mass ratio of 3:2. The crosslinking initiator is 2,4,6-trimethylbenzoyl-diphenylphosphine oxide.

A support body is prepared by using a photo-curing 3D printing method; the support body is used to form a skeleton of a first wall on a double-wall cold ceramic core after degreasing, and the first wall is a wall with a thickness greater than 5 mm.

In this step, the supporting agent, fixing agent, filler and toughening agent are mechanically stirred for 80 minutes to obtain a mixed powder. After adding a shrinkage reducing agent and a crosslinking initiator to the crosslinking agent and stirring at 120°C for 30 minutes, the mixed powder is added thereto and mechanically stirred for 270 minutes. During the stirring process, a dispersant is added successively to prepare a light-cured ceramic slurry, and a double-walled cold ceramic core support is cured and formed using a light-curing 3D printing device.

Among them, there are 25 parts by weight of supporting agent, 20 parts by weight of fixing agent, 15 parts by weight of filler, 5 parts by weight of toughening agent, 15 parts by weight of crosslinking agent, 10 parts by weight of shrinkage reducing agent, 5 parts by weight of crosslinking initiator and 5 parts by weight of dispersant.

Among them, the supporting agent is silica with a particle size of 25 μm; the fixing agent is silica powder with a particle size of 1 μm; the filler is silica powder with a particle size of 0.3 μm; the toughening agent is quartz fiber with a diameter of 200 nm and a length of 400 μm; the cross-linking agent is alkoxylated pentaerythritol tetraacrylate with a molecular weight of 438; the shrinkage reducing agent is polysilsesquioxane; the cross-linking agent initiator is bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide; and the dispersant is BYK111.

Hot injection molding step: assemble the resin mold and the support body in the outer mold; then, inject the ceramic core slurry into the outer mold for hot injection molding to form a ceramic blank. The injection temperature is 120°C, the mold temperature is 80°C, the injection pressure is 4Mpa, the injection time is 80s, and the holding time is 100s.

The resin forming mold and the support body are assembled and installed in the outer metal mold for double-wall cold ceramic core forming for standby use. The ceramic core slurry is injected into the outer metal mold with the resin mold and the support body installed inside by hot injection equipment to obtain a ceramic blank with the ceramic slurry covering the resin mold.

The paraffin wax and silicon dioxide ceramic powder are stirred at a temperature of 180°C to obtain a ceramic core slurry. In the ceramic core slurry, the mass fraction of the paraffin wax is 23%, and the mass fraction of the silicon dioxide ceramic powder is 77%. The ceramic powder is silicon dioxide. The particle size of the silicon dioxide ceramic powder is 20 microns.

Degreasing and sintering treatment steps: the ceramic blank is subjected to degreasing treatment and sintering treatment in sequence to obtain a double-wall cold ceramic core.

The degreasing treatment is as follows: the ceramic green body is heated to 150°C at a heating rate of 3°C/min in air and kept warm for 180 minutes; then heated to 400°C at a heating rate of 1°C/min and kept warm for 300 minutes; then heated to 700°C at a heating rate of 5°C/min and kept warm for 180 minutes; finally, cooled to room temperature at a cooling rate of 3°C/min.

The sintering parameters are as follows: in air, the degreased ceramic blank is heated to 1250°C at a heating rate of 8°C/min, kept at this temperature for 270 minutes, and then cooled at a cooling rate of 7°C/min to obtain a double-walled cold ceramic core.

Comparative Example 1

Comparative Example 1 prepares a double-wall cold ceramic core. The difference between Comparative Example 1 and Example 1 is that the viscosity regulator (isobornyl acrylate with a molecular weight of 208) in the raw material for preparing the resin mold is replaced with ethoxylated trimethylolpropane triacrylate with a molecular weight of 428; the rest of the formula, preparation process, degreasing and sintering process are exactly the same as Example 1.

Comparative Example 2

Comparative Example 2: A double-wall cold ceramic core is prepared. The difference between this comparative example and Example 2 is that the particle size of the supporting agent is changed to 5 μm; the rest of the formula, preparation process, degreasing and sintering process are completely consistent with Example 2.

Comparative Example 3

Comparative Example 3 prepares a double-wall cold ceramic core. The difference between this comparative example and Example 2 is that the degreasing process is changed to heating the temperature to 400°C at a heating rate of 5°C/min, keeping it warm for 360 minutes, and then cooling it to room temperature at a cooling rate of 1°C/min; the rest of the formula, preparation process, degreasing and sintering process are exactly the same as Example 2.

Comparative Example 4

This comparative example provides a method for preparing a double-wall cold ceramic core by additive-isotropic synergistically, which mainly comprises the following steps:

Prepare the double-wall cold ceramic core parting mold: respectively mold the two sides of the double-wall cold core, the thin-wall area of the trailing edge, and the thick trunk part, and set and prepare three sets of metal shape molds.

Hot injection molding steps: Use hot injection equipment to inject the ceramic core slurry into three sets of metal shape molds to obtain ceramic core parting blanks. Among them, the injection temperature is 100℃, the mold temperature is 80℃, the injection pressure is 3.5Mpa, the injection time is 90s, and the holding time is 180s.

The preparation steps of the ceramic core slurry are as follows: paraffin wax and ceramic powder are stirred at a temperature of 160° C. to obtain the ceramic core slurry. In the ceramic core slurry, the mass fraction of paraffin wax is 20%, the mass fraction of ceramic powder is 80%, and the composition of the ceramic powder is silicon dioxide.

Degreasing and sintering treatment steps: the ceramic blank is subjected to degreasing treatment and sintering treatment in sequence to obtain a double-wall cold ceramic core.

The degreasing treatment is as follows: the ceramic green body is heated to 200°C in air at a heating rate of 1°C/min, and kept warm for 120 minutes; then heated to 350°C at a heating rate of 2°C/min, and kept warm for 60 minutes; then heated to 600°C at a heating rate of 4°C/min, and kept warm for 180 minutes; finally, cooled to room temperature at a heating rate of 3°C/min.

The sintering parameters are as follows: in air, the degreased ceramic blank is heated to 1200°C at a heating rate of 5°C/min, kept at this temperature for 360 minutes, and then cooled at a cooling rate of 5°C/min to obtain a double-walled cold ceramic core.

The steps of assembling the ceramic core parting sintered body are as follows: the trailing edge parting is bonded to the core trunk parting with ceramic glue, and then the thin-walled areas on both sides of the core are bonded one by one with purchased quartz ceramic tubes to obtain a double-walled cold ceramic core formed by multiple sets of molds.

The test data of the strength, solubility and dimensional accuracy of the double-walled cold ceramic core of the resin molds prepared in the above Examples 1-2 and Comparative Examples 1-3 are shown in Table 1.

Table 1

From the above examples, comparative examples and the data in Table 1, it can be seen that:

(1) Compared with Comparative Example 4, the scheme of the embodiment of the present invention greatly reduces the number of molds in the hot pressing and parting process for preparing double-walled cold ceramic cores that are generally applicable at this stage, realizes the integrated removal of the paraffin of the resin mold, the core blank, and the resin in the support body, shortens the preparation cycle and reduces the preparation cost. The one-piece molding method significantly eliminates the errors caused by the core assembly and significantly improves the accuracy of the core. In addition, the scheme of the embodiment of the present invention can significantly solve the cracking and deformation problems caused by the shrinkage and deformation inconsistency of thick and thin areas, and the prepared core has high strength, few defects, few cracks, and high precision.

(2) Comparative Examples 1-3 illustrate that the present invention is a mutually coupled design of ceramic particle size, resin composition design (especially resin molecular weight) and degreasing process, none of which can be missing. Otherwise, problems such as surface cracking or delamination of the support body and the surface layer are likely to occur, resulting in reduced accuracy and strength.

The scheme of the present invention clearly defines the molecular weight of the resin (such as the viscosity regulator) in order to couple it with the degreasing and sintering parameters and control the order of resin decomposition and degreasing.

The powder particle size of the present invention is designed as follows: the particle size of the support body is larger than the particle size of the outer skin, which reduces the shrinkage of the support body during sintering and avoids cracking of the skin and the support body. In addition, the powders of the supporting agent, curing agent, and filler in the support body are coarse and fine, which avoids the problem of too low strength of the support body and difficulty in sintering.

The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention still falls within the scope of the technical solution of the present invention.

Claims (10)

1. A method for preparing a double-wall cold ceramic core by additive-isotropic material synergistically, characterized in that it comprises the following steps: A resin mold is prepared by using a light-curing 3D printing method; the resin mold is used to form a hollow structure of a double-wall cold ceramic core; Prepare a support body by using a photo-curing 3D printing method; the support body is used to form a skeleton of a first wall on a double-wall cold ceramic core after degreasing, and the first wall is a wall with a thickness greater than 5 mm; Hot-pressing molding step: assembling the resin mold and the support body in the outer mold; then, injecting the ceramic core slurry into the outer mold for hot-pressing molding to form a ceramic blank; Degreasing and sintering treatment steps: the ceramic blank is subjected to degreasing treatment and sintering treatment in sequence to obtain a double-wall cold ceramic core. 2. The method for preparing a double-wall cold ceramic core by additive-isotropic materials according to claim 1, characterized in that in the step of preparing the resin mold: Performing a photocurable 3D printing process on a photocurable molding resin to obtain a resin mold; wherein, in parts by weight, the photocurable molding resin comprises 45-55 parts by weight of a viscosity modifier, 25-35 parts by weight of a crosslinking agent, and 5-15 parts by weight of a crosslinking initiator; Preferably, the viscosity modifier, the crosslinking agent and the crosslinking initiator are stirred at a temperature of 40-80° C. for 60-360 minutes to obtain the light-curable molding resin. 3. The method for preparing a double-wall cold ceramic core by additive-isotropic material synergistically according to claim 2, characterized in that: The viscosity modifier is one or more of isobornyl acrylate, ethoxylated oxyphenyl acrylate, and octadecyl acrylate; and/or The cross-linking agent is one or more of tricyclodecyl dimethanol diacrylate, propoxylated neopentyl glycol diacrylate, dipropylene glycol diacrylate, and tripropylene glycol diacrylate; and/or The crosslinking initiator is one or more of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2-hydroxy-2-methyl-1-phenylacetone-1, and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide; and/or The molecular weight of the viscosity modifier is 150-240; and/or The molecular weight of the cross-linking agent is 240-350. 4. The method for preparing a double-wall cold ceramic core by additive-isotropic materials according to claim 1, characterized in that in the step of preparing the support body: The photocurable ceramic slurry is subjected to photocuring 3D printing treatment to obtain a support body; wherein, the photocurable ceramic slurry includes, in parts by weight: 25-35 parts by weight of a supporting agent, 10-20 parts by weight of a fixing agent, 5-15 parts by weight of a filler, 3-10 parts by weight of a toughening agent, 15-20 parts by weight of a crosslinking agent, 10-15 parts by weight of a shrinkage reducing agent, 2-5 parts by weight of a crosslinking initiator, and 2-5 parts by weight of a dispersant. 5. The method for preparing a double-wall cold ceramic core by additive-isotropic materials according to claim 4, characterized in that in the step of preparing the support body: The supporting agent, fixing agent, filler and toughening agent are stirred and mixed for 30-90 minutes to obtain a mixed powder; After adding a shrinkage reducing agent and a crosslinking initiator to the crosslinking agent, stirring is performed at a temperature of 60-120° C. for 30-90 minutes, and then the mixed powder is added thereto and stirred for 120-360 minutes; during the stirring process, a dispersant is added in batches, and after stirring, a light-cured ceramic slurry is obtained. 6. The method for preparing a double-walled cold ceramic core by additive-isotropic materials according to claim 4, characterized in that: The supporting agent is one or both of alumina and silica; and/or The fixing agent is one or both of zircon powder and silicon dioxide; and/or The filler is one or both of zircon powder and silicon dioxide; and/or The toughening agent is one or more of mullite fiber, quartz fiber, and alumina fiber; and/or The cross-linking agent is one or more of ethoxylated trimethylolpropane triacrylate, propoxylated glycerol triacrylate, alkoxylated pentaerythritol tetraacrylate, and dimethylolpropane tetraacrylate; and/or The shrinkage reducing agent is one or more of polyborosilazane, polysilicone carbodiimide, and polysilsesquioxane; and/or The crosslinking agent initiator is one or more of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2-hydroxy-2-methyl-1-phenylacetone-1, and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide; and/or The dispersant is one or more of BYK-9076, BYK111, and KOS110. 7. The method for preparing a double-wall cold ceramic core by additive-isotropic material synergistically according to claim 4, characterized in that the molecular weight of the cross-linking agent is 400-500; and/or The particle size of the supporting agent is 25-75 μm; and/or The particle size of the fixing agent is 1-5 μm; and/or The particle size of the filler is 0.1-0.5 μm; and/or The toughening agent has a diameter of 10-200 nm and a length of 200-400 μm. 8. The method for preparing a double-wall cold ceramic core by additive-isotropic material synergistically according to any one of claims 1 to 7, characterized in that in the hot injection molding step: In terms of weight percentage, the ceramic core slurry comprises 20-30% paraffin wax and 70-80% ceramic powder; preferably, the paraffin wax and the ceramic powder are stirred at a temperature of 120-180° C. to obtain the ceramic core slurry; preferably, the ceramic powder is silicon dioxide ceramic powder; preferably, the particle size of the silicon dioxide ceramic powder is 1-25 μm; and/or The parameters of the hot injection molding are set as follows: injection temperature is 80-150°C, mold temperature is 50-100°C, injection pressure is 3.5-5.5Mpa, injection time is 60-90s, and holding time is 60-180s. 9. The method for preparing a double-wall cold ceramic core by additive-isotropic materials according to any one of claims 1 to 8, characterized in that in the degreasing and sintering steps: The degreasing treatment comprises: heating the ceramic blank to 150-300°C at a first heating rate and keeping the temperature for 120-180 minutes; then, heating the blank to 300-400°C at a second heating rate and keeping the temperature for 60-360 minutes; then, heating the blank to 500-700°C at a third heating rate and keeping the temperature for 180-360 minutes, and then cooling the blank to room temperature at a first cooling rate to obtain a degreasing ceramic blank; preferably, the atmosphere of the degreasing treatment is air; preferably, the first heating rate is 1-3°C/min, the second heating rate is 1-2°C/min, the third heating rate is 2-5°C/min, and the first cooling rate is 1-5°C/min; and/or The sintering process comprises: heating the degreased ceramic blank to 1000-1400°C at a fourth heating rate, keeping the temperature for 240-360 minutes, and then cooling at a second cooling rate to obtain a double-wall cold ceramic core; preferably, the sintering atmosphere is air; preferably, the fourth heating rate is 5-8°C/min; and the second cooling rate is 5-8°C/min. 10. A double-walled cold ceramic core, characterized in that the double-walled cold ceramic core is prepared by the preparation method of the double-walled cold ceramic core described in any one of claims 1 to 9; preferably, the double-walled cold ceramic core comprises a first wall with a thickness greater than 5 mm and a second wall with a thickness less than 1 mm; the double-walled cold ceramic core has a hollow structure; preferably, the hollow structure comprises voids.