Method for forming complex and compact cavity precision casting based on 3D printing ceramic core

Abstract

The invention discloses a method for forming a complex and compact cavity precision casting based on a 3D printing ceramic core, and belongs to the technical field of precision casting. The ceramic core of the whole casting inner cavity structure is directly formed through the 3D printing technology, and the number and types of tools and cores needed during casting wax mold forming can be reduced; errors generated during splicing of the mold cores are fundamentally eliminated, the machining precision is improved, meanwhile, the machining difficulty can be reduced, particularly forming of fine structures such as narrow edges and sharp corners is facilitated, the ceramic mold core and a casting shell can form an assembly together, the inner cavity structure of a casting does not need to be manufactured during shell manufacturing, and the production cost is reduced. And the difficulty during shell manufacturing is greatly reduced, the problem of refractory material accumulation or cavity in the deep groove and narrow groove part in the shell manufacturing process is avoided, the risks of looseness and steel leakage of the deep groove and narrow groove part of the casting are reduced, and technical support is provided for achieving automatic shell manufacturing of the high-integration complex compact cavity precision casting.

Description

Technical Field

[0001] The present invention relates to the technical field of precision casting, and in particular to a method for forming a complex and compact cavity precision casting based on a 3D printed ceramic core. Background Art

[0002] Aircraft engine casings are important precision castings of cavity structures in aircraft engines. Currently, they are mainly formed in one piece using the investment casting process. Compared with segmented welding forming, they have the advantages of short manufacturing process, low machining difficulty, high strength and dimensional accuracy.

[0003] However, with the improvement of performance and life of modern advanced aircraft engines, precision casing castings are constantly developing towards functional integration, integrating many special-shaped oil pipes, mounting seat bosses and other functional components with special-shaped curved surface base structures. The inner cavity structure becomes extremely complex and compact, and many special-shaped deep and narrow groove structures are formed, which makes it difficult to form them in one piece through wax mold pressing dies, such as Figure 1-2 As shown, in order to form a complex and compact cavity structure of a highly integrated precision casing casting, the prior art usually uses a soluble core to indirectly form the inner cavity structure, and uses a soluble core that matches the inner cavity structure of the casting to form the wax mold cavity during the wax mold pressing process. After the wax mold is pressed and formed, the soluble core of the wax mold cavity is removed to obtain a complex and compact cavity wax mold of the casting.

[0004] The use of soluble core technology to form highly integrated, complex and compact cavity precision castings has the following shortcomings:

[0005] 1. The soluble core has low strength, poor stability, and is prone to cracks. It often needs to be repaired to ensure the surface quality and shape and size accuracy of the wax model, shell and casting;

[0006] 2. It is becoming increasingly difficult to use soluble core molds to press and mold the inner cavity of highly integrated, complex and compact precision castings. It often requires multiple sets of soluble core molds to be pressed and molded in sections, and then assembled and molded by positioning tooling. This is prone to assembly dislocation, which seriously affects the position and dimensional accuracy of the inner cavity of the casting;

[0007] 3. The complex and compact cavity structure of the casting still needs to be formed through the shell preparation. The shell preparation of deep, wide or narrow grooves is difficult, the shell thickness is uneven, and the heat dissipation conditions are poor if the shell is too thick, which can easily lead to looseness and crack defects in the casting. If the shell is too thin, the strength is low and it is easy to cause steel leakage and inclusion defects.

[0008] Based on this, the present invention designs a method for forming complex and compact cavity precision castings based on 3D printing ceramic cores to solve the above problems. Summary of the invention

[0009] To achieve the above object, the present invention provides the following technical solution: a method for forming a complex and compact cavity precision casting based on a 3D printed ceramic core, comprising the following steps:

[0010] S1, model design: according to the inner cavity structure of the casting, design a three-dimensional model of the ceramic core that matches the inner cavity structure of the casting;

[0011] S2, ceramic core printing: according to the three-dimensional model of the ceramic core, the ceramic core is prepared by 3D printing technology;

[0012] S3, casting wax mold pressing: placing the prepared ceramic core into the cavity of the wax mold pressing mold to press and form the casting wax mold;

[0013] S4, preparing a casting shell: coating a refractory material on a surface of the casting wax mold where the surface is not in contact with the ceramic core to prepare a casting shell, so that the casting shell is adjacent to the ceramic core, and obtaining a combination of the casting shell and the ceramic core after dewaxing;

[0014] S5, melting and pouring: pouring molten metal into the combination of the casting shell and the ceramic core, and waiting for the molten metal to cool to form a casting;

[0015] S6, casting shelling: removing the casting shell and ceramic core on the surface of the casting to obtain a rough casting.

[0016] As a further solution of the present invention, in step S1, when designing the three-dimensional model of the ceramic core, the wall thickness at different positions of the three-dimensional model is designed according to the heat dissipation conditions of the inner cavity structure of the casting.

[0017] As a further scheme of the present invention, in step S1, when designing the three-dimensional model of the ceramic core, it is necessary to consider the riser scheme of the casting. If a riser is required in the inner cavity of the casting, a riser neck is opened at the corresponding position of the three-dimensional model of the ceramic core according to the position and shape of the riser, and the riser neck passes through the inner cavity surface and the outer surface of the ceramic core.

[0018] As a further solution of the present invention, when a riser neck is opened in the three-dimensional model of the ceramic core, a film is arranged inside the riser neck of the three-dimensional model to seal the riser neck, and the film has a preset distance in the axial direction of the riser neck from one end of the riser neck for installing the riser wax mold.

[0019] As a further solution of the present invention, in step S4, before coating the refractory material on the surface of the casting wax mold, the openings at both ends of the ceramic core are closed to prevent the refractory material from entering the inner cavity of the ceramic core during the preparation of the casting shell.

[0020] As a further scheme of the present invention, in step S4, if a runner and / or riser needs to be set in the inner cavity of the casting, low-temperature wax is applied or a release agent is sprayed on the non-runner and riser positions of the inner cavity of the ceramic core, and then the riser and runner are combined in the riser neck of the ceramic core, and the ceramic core and the casting wax mold are fully coated with refractory materials. After the casting shell is prepared, the excess refractory material on the surface of the ceramic core is removed.

[0021] As a further solution of the present invention, when the surface of the ceramic core is coated with the refractory material, a shell cleaning groove is scraped out on the refractory material covering the surface of the ceramic core.

[0022] As a further solution of the present invention, in step S1, when designing the three-dimensional model of the ceramic core, reinforcing ribs are provided according to the shrinkage variation law of the ceramic core.

[0023] A casting is prepared by using the above-mentioned method for forming a complex and compact cavity precision casting based on a 3D printed ceramic core.

[0024] The present invention has the following beneficial effects:

[0025] This method uses 3D printing technology to directly form a ceramic core for the entire casting cavity structure, which can reduce the number and types of tooling and cores required for casting wax mold molding, fundamentally eliminate the errors caused by splicing between cores, and reduce the processing difficulty while improving processing accuracy. At the same time, the ceramic core has high strength, good stability, and easy positioning, which is beneficial to improving the shape and position dimensional control accuracy and stability of highly integrated complex and compact cavity precision castings, and is particularly beneficial to forming fine structures such as narrow edges and sharp corners. The ceramic core can form an assembly with the casting shell, and there is no need to make a shell for the casting cavity structure during shell preparation, which greatly reduces the difficulty of shell making, avoids the accumulation of refractory materials or voids in deep groove and narrow groove parts during shell preparation, reduces the risk of looseness and steel leakage in deep groove and narrow groove parts of castings, and provides technical support for the automated shell preparation of highly integrated complex and compact cavity precision castings.

[0026] In addition to the above-described purposes, features and advantages, the present invention has other purposes, features and advantages. The present invention will be further described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0028] Figure 1 It is a schematic diagram of a soluble core molding wax mold in the prior art.

[0029] Figure 2It is a schematic diagram of the shell structure of the prior art.

[0030] Figure 3 Schematic diagram of the process of this method.

[0031] Figure 4 Schematic diagram of the ceramic core structure in this method.

[0032] Legend:

[0033] 1. Ceramic core; 2. Casting wax mold; 3. Riser neck; 4. Thin film; 5. Reinforcement ribs. DETAILED DESCRIPTION

[0034] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below.

[0035] See also Figure 1-4 The present invention provides a technical solution: a method for forming a complex and compact cavity precision casting based on a 3D printed ceramic core, comprising the following steps:

[0036] S1, model design: according to the inner cavity structure of the casting, design a three-dimensional model of the ceramic core 1 matching the inner cavity structure of the casting;

[0037] S2, printing of ceramic core 1: preparing ceramic core 1 by 3D printing technology according to the three-dimensional model of ceramic core 1;

[0038] S3, pressing the casting wax mold 2: placing the prepared ceramic core 1 into the cavity of the wax mold pressing mold to press and form the casting wax mold 2;

[0039] S4, preparing a casting shell: coating a refractory material on the surface of the casting wax mold 2 where the surface is not in contact with the ceramic core 1 to prepare a casting shell, so that the casting shell is adjacent to the ceramic core 1, and after dewaxing, a combination of the casting shell and the ceramic core 1 is obtained;

[0040] S5, melting and pouring: pouring molten metal into the combination of the casting shell and the ceramic core 1, and waiting for the molten metal to cool to form a casting;

[0041] S6, casting shelling: removing the casting shell and the ceramic core 1 on the surface of the casting to obtain a rough casting.

[0042] The method uses 3D printing technology to prepare a ceramic core 1 that matches the inner cavity structure of the casting, which is used to form the inner cavity structure of the casting wax mold 2 during the pressing process of the casting wax mold 2. The ceramic core 1 of the entire inner cavity structure of the casting is directly formed by 3D printing, which can effectively reduce the number and types of tooling and cores required for the molding of the casting wax mold 2, thereby reducing the difficulty of operation and production cost. At the same time, the ceramic core 1 has high strength, good stability, and is easy to position, which is conducive to improving the shape and position size control accuracy and stability of highly integrated complex and compact cavity precision castings, and is particularly conducive to forming fine structures such as narrow edges and sharp corners therein;

[0043] After the casting wax mold 2 is pressed and formed, the ceramic core 1 is not removed from the casting wax mold 2, and the next step of shell preparation process is directly carried out. Since the ceramic core 1 is designed according to the inner cavity structure of the casting, after the casting wax mold 2 is formed, the ceramic core 1 is arranged in the inner cavity of the casting wax mold 2, and the part where the inner cavity of the casting wax mold 2 contacts the ceramic core 1 does not need to be shelled, which greatly reduces the difficulty of preparing the casting shell, can effectively avoid the accumulation or void of refractory materials in the deep groove and narrow groove parts during the shell preparation process, reduce the risk of looseness and steel leakage in the deep groove and narrow groove parts of the casting, and provide technical support for the realization of automated shell preparation for highly integrated, complex and compact cavity precision castings;

[0044] In the process of preparing the shell, a refractory material is coated on the surface of the casting wax mold 2 at a position not in contact with the ceramic core 1 to form a casting shell, and the casting shell is adjacent to the ceramic core 1 in the inner cavity of the casting wax mold 2, so that the casting shell and the ceramic core 1 are fixed together to form a combination of the casting shell and the ceramic core 1, and then the casting wax mold 2 in the inner cavity of the combination is removed to obtain a combination with a cavity inside, and the inner cavity of the combination is used to form a casting, and then molten metal is poured into the inner cavity of the combination, and after the molten metal is cooled, the surface casting shell and the ceramic core 1 are removed to obtain a rough casting;

[0045] The method adopts 3D printing technology to directly form the ceramic core 1 of the entire casting cavity structure, which can reduce the number and types of tooling and cores required for molding the casting wax mold 2, fundamentally eliminate the errors generated when splicing the cores, and reduce the processing difficulty while improving the processing accuracy. At the same time, the ceramic core 1 has high strength, good stability, and simple positioning, which is beneficial to improving the shape and position size control accuracy and stability of highly integrated complex and compact cavity precision castings, and is particularly beneficial to forming fine structures such as narrow edges and sharp corners. The ceramic core 1 can form an assembly together with the casting shell. When preparing the shell, there is no need to make a shell for the casting cavity structure, which greatly reduces the difficulty of shell making, avoids the accumulation of refractory materials or voids in deep groove and narrow groove parts during shell preparation, reduces the risk of looseness and steel leakage in deep groove and narrow groove parts of castings, and provides technical support for realizing automated shell preparation for highly integrated complex and compact cavity precision castings.

[0046] Specifically, in step S1, when designing the three-dimensional model of the ceramic core 1, the wall thickness at different positions of the three-dimensional model is designed according to the heat dissipation conditions of the inner cavity structure of the casting, and the wall thickness at different positions of the ceramic core 1 is controlled to control the temperature field of the molten metal during smelting and pouring in step S5, which helps to achieve accurate and orderly control of the solidification temperature field of the molten metal;

[0047] The more complex the inner cavity structure of the casting is, the more difficult it is to control the solidification temperature field of the molten metal during the smelting and pouring process. After the traditional casting shell is prepared, it is necessary to attach insulation subsidies to the surface of the casting shell according to the solidification temperature field of the molten metal during smelting and pouring to control the solidification temperature field of the molten metal. However, the shape, thickness and installation position of the insulation subsidies cannot be accurately controlled and are greatly affected by manual errors, resulting in the insulation subsidies failing to achieve the expected control effect on the solidification temperature field of the molten metal, and a high scrap rate. However, in the present method, the ceramic core 1 is used to form a mold cavity of the molded casting together with the casting shell during the smelting and pouring process, that is, the solidification temperature field of the molten metal can be directly controlled by controlling the thickness of the ceramic core 1. The ceramic core 1 is prepared by 3D printing technology. When designing a three-dimensional model of the ceramic core 1, the thickness of the ceramic core 1 at different positions can be designed according to the solidification temperature field of the molten metal, and different heat dissipation conditions can be achieved at different thickness positions, so as to accurately control the solidification temperature field of the molten metal.

[0048] For example, in the thin-walled parts of the casting, the molten metal carries less energy during pouring, and the heat is dissipated by radiation from the inside to the outside. Therefore, the molten metal in the thin-walled parts of the casting dissipates heat faster. If the heat dissipation speed of the molten metal in the thin-walled parts of the casting needs to be controlled, the traditional solution is generally to add thermal insulation subsidies on the surface of the mold shell. In the design stage of the ceramic core 1, the wall thickness of the ceramic core 1 can be differentiated. The thickness of the ceramic core 1 at the thin-walled position of the molded casting can be thicker, while the thickness of the ceramic core 1 at the thick-walled position of the molded casting can be thinner, so as to control the solidification temperature field of the molten metal. Of course, the temperature field of the molten metal in the actual pouring process is very complex, and simulation is required to obtain the wall thickness of the specific ceramic core 1 at different positions.

[0049] Specifically, in step S4, before coating the surface of the casting wax mold 2 with refractory material, the openings at both ends of the ceramic core 1 are closed to prevent the refractory material from entering the inner cavity of the ceramic core 1 during the preparation of the casting shell;

[0050] In the process of preparing the casting shell, if the inner cavity of the casting is not provided with a riser or a runner, it is not necessary to coat the ceramic core 1 with a refractory material. In this case, the openings at both ends of the ceramic core 1 can be closed to prevent the refractory material from entering the inner cavity of the ceramic core 1 during the preparation of the casting shell, so as to ensure that the heat dissipation performance of the ceramic core 1 will not be affected by the refractory material covering;

[0051] When closing the openings at both ends of the ceramic core 1, end covers or film coverings may be used.

[0052] Specifically, in step S1, when designing the three-dimensional model of the ceramic core, the riser scheme of the casting needs to be considered. If the inner cavity of the casting needs to be provided with a riser, such as Figure 4 As shown, a riser neck 3 is opened at a corresponding position of the three-dimensional model of the ceramic core 1 according to the position and shape of the riser, and the riser neck 3 passes through the inner cavity surface and the outer surface of the ceramic core 1. After the casting wax mold 2 is pressed and formed, the riser can be installed in the riser neck 3, which ensures that the riser installation position is accurate and the riser installation is simpler;

[0053] When designing a casting smelting and pouring scheme, a riser may be set in the inner cavity of the casting. In the traditional process, it is necessary to first form the casting wax mold 2 and then fix the riser wax mold at the position where the riser is required on the surface of the casting wax mold 2, and then prepare the casting shell. The riser is formed on the casting shell through the riser wax mold. During the installation of the riser wax mold, the riser wax mold needs to be positioned. If the positioning is not accurate enough, it will affect the filling of the molten metal during the subsequent smelting and pouring process. In the method, when designing the three-dimensional model of the ceramic core 1, a riser neck 3 for installing the riser wax mold is pre-opened on the three-dimensional model. After the part wax mold is formed by the ceramic core 1, the riser wax mold is directly installed in the riser neck 3 opened in the ceramic core 1, and the riser wax mold is positioned by the riser neck 3 to ensure that the final riser position is accurate, improve the consistency of the wax mold tree assembly, and reduce the difficulty of installing the riser wax mold.

[0054] Specifically, when the three-dimensional model of the ceramic core 1 opens a riser neck 3, a film sheet 4 is arranged in the riser neck 3 of the three-dimensional model to seal the riser neck 3, and the film sheet 4 has a preset distance from one end of the riser neck 3 for installing the riser wax mold in the axial direction of the riser neck 3 to prevent the wax mold material from filling the riser neck 3 when the casting wax mold 2 is formed by the ceramic core 1, and ensure that there is a position for installing the riser wax mold in the riser neck 3;

[0055] After the riser neck 3 is opened on the surface of the ceramic core 1, when the wax mold of the part is formed by the ceramic core 1, the wax mold material will enter the riser neck 3 after being squeezed and fill the entire riser neck 3. After the casting wax mold 2 is formed, the riser wax mold cannot be installed in the riser neck 3 opened by the ceramic core 1. The wax mold in the riser neck 3 needs to be cleaned before the riser wax mold can be installed. Therefore, when designing the three-dimensional model of the ceramic core 1, if the ceramic core 1 has a riser neck 3 on its surface, such as Figure 4As shown, a film sheet 4 needs to be arranged in the riser neck 3, and the film sheet 4 is used to prevent the wax mold from filling the entire riser neck 3 during the molding process of the casting wax mold 2, and a space for installing the riser wax mold flows out on one side of the riser neck 3 for installing the riser wax mold. After the casting wax mold 2 is pressed and formed, the film sheet 4 in the riser neck 3 is removed, and then the riser wax mold is installed in the riser neck 3, so as to reduce the difficulty of installing the riser wax mold in the riser neck 3;

[0056] The thickness of the film sheet 4 is designed according to the pressure of the wax model material when the casting wax model 2 is pressed, to ensure that the film sheet 4 can resist the pressure of the wax model material, and also to facilitate the removal of the film sheet 4 after the subsequent casting wax model 2 is pressed and formed.

[0057] Specifically, in step S4, if a runner and / or a riser are required to be provided in the inner cavity of the casting, low-temperature wax is coated or a release agent is sprayed on the non-runner and riser positions of the inner cavity of the ceramic core 1, and then the riser and runner are combined in the riser neck 3 of the ceramic core 1, and the ceramic core 1 and the casting wax mold 2 are fully coated with refractory materials. After the preparation of the casting shell is completed, the excess refractory material on the surface of the ceramic core 1 is removed, and by coating low-temperature wax or spraying a release agent, the refractory material can be more easily detached from the surface of the ceramic core 1 after covering the inner cavity of the ceramic core 1, so that the excess casting shell on the surface of the ceramic core 1 can be removed after the preparation of the casting shell is completed;

[0058] When designing the riser and runner of a casting, there may be a situation where the riser or runner is located in the inner cavity of the casting. At this time, the ceramic core 1 used to form the inner cavity structure of the casting needs to be connected to the riser or runner, and the surfaces of the riser and runner need to be coated with refractory materials. In the process of coating the refractory materials, first apply low-temperature wax or spray a release agent on the non-runner and riser positions of the inner cavity of the ceramic core 1. In this way, after the ceramic core 1 and the casting wax mold 2 are coated with refractory materials and dried to obtain the casting shell, the excess casting shell on the surface of the ceramic core 1 can be more easily removed to prevent the casting shell from affecting the heat dissipation of the ceramic core 1.

[0059] Optionally, when the surface of the ceramic core 1 is coated with a refractory material, a shell cleaning groove is scraped out on the refractory material covering the surface of the ceramic core 1, so as to facilitate cleaning of excess refractory material on the surface of the ceramic core 1 after the refractory material is coated on the surface of the ceramic core 1;

[0060] When the surface of the ceramic core 1 is coated with a refractory material, before the refractory material is dried and sintered, a plurality of shell cleaning grooves can be scraped out on the refractory material on the surface of the ceramic core 1 with a tool. In this way, after the subsequent casting shell preparation is completed, the shell cleaning groove divides the casting shell on the surface of the ceramic core 1 into multiple areas, and the casting shell is cleaned along the dividing lines of the shell cleaning groove, which makes cleaning easier.

[0061] Furthermore, the shell cleaning groove can be opened at the edge of the riser and the runner, so as to prevent the riser and the runner from being damaged when cleaning the casting shell on the surface of the ceramic core 1, thereby protecting the safety of the riser and the runner.

[0062] Specifically, in step S1 , when designing the three-dimensional model of the ceramic core 1 , reinforcing ribs 5 are provided according to the shrinkage variation law of the ceramic core 1 to prevent cracks from being generated during the molding and use of the ceramic core 1 .

[0063] A casting is prepared by using the above-mentioned method for forming a complex and compact cavity precision casting based on a 3D printed ceramic core.

[0064] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for forming complex and compact cavity precision castings based on 3D printing ceramic cores, characterized in that: The following steps are involved: S1, model design: according to the inner cavity structure of the casting, design a three-dimensional model of the ceramic core (1) matching the inner cavity structure of the casting; S2, printing the ceramic core (1): preparing the ceramic core (1) by using 3D printing technology according to the three-dimensional model of the ceramic core (1); S3, pressing the casting wax mold (2): placing the prepared ceramic core (1) into the mold cavity of the wax mold pressing mold, and pressing the casting wax mold (2); S4, preparing a casting shell: coating a refractory material on the surface of the casting wax mold (2) at a position not in contact with the ceramic core (1) to prepare a casting shell, so that the casting shell is adjacent to the ceramic core (1), and after dewaxing, a combination of the casting shell and the ceramic core (1) is obtained; S5, melting and pouring: pouring molten metal into the combination of the casting shell and the ceramic core (1), and waiting for the molten metal to cool to form a casting; S6, casting shelling: removing the casting shell and ceramic core (1) on the surface of the casting to obtain a rough casting.

2. A method for forming complex and compact cavity precision castings based on 3D printing ceramic cores according to claim 1, characterized in that: In step S1, when designing the three-dimensional model of the ceramic core (1), the wall thickness at different positions of the three-dimensional model is designed according to the heat dissipation conditions of the inner cavity structure of the casting.

3. The method for forming complex and compact cavity precision castings based on 3D printing ceramic cores according to claim 1, characterized in that: In step S1, when designing the three-dimensional model of the ceramic core, it is necessary to consider the riser scheme of the casting. If a riser is required in the inner cavity of the casting, a riser neck (3) is opened at a corresponding position of the three-dimensional model of the ceramic core (1) according to the position and shape of the riser. The riser neck (3) passes through the inner cavity surface and the outer surface of the ceramic core (1).

4. A method for forming complex and compact cavity precision castings based on 3D printing ceramic cores according to claim 3, characterized in that: When a riser neck (3) is opened in the three-dimensional model of the ceramic core (1), a film sheet (4) is arranged in the riser neck (3) of the three-dimensional model to seal the riser neck (3), and the film sheet (4) has a preset distance in the axial direction of the riser neck (3) from an end of the riser neck (3) for mounting the riser wax mold.

5. The method for forming complex and compact cavity precision castings based on 3D printing ceramic cores according to claim 1, characterized in that: In step S4, before coating the surface of the casting wax mold (2) with refractory material, the openings at both ends of the ceramic core (1) are closed to prevent the refractory material from entering the inner cavity of the ceramic core (1) during the preparation of the casting shell.

6. The method for forming complex and compact cavity precision castings based on 3D printing ceramic cores according to claim 3, characterized in that: In step S4, if a runner and / or a riser are required to be provided in the inner cavity of the casting, low-temperature wax is applied or a mold release agent is sprayed on the non-runner and riser positions of the inner cavity of the ceramic core (1), and then the riser and runner are combined in the riser neck (3) of the ceramic core (1), and the ceramic core (1) and the casting wax mold (2) are fully coated with refractory material. After the casting shell is prepared, the excess refractory material on the surface of the ceramic core (1) is removed.

7. A method for forming complex and compact cavity precision castings based on 3D printing ceramic cores according to claim 6, characterized in that: When the surface of the ceramic core (1) is coated with refractory material, a shell cleaning groove is scraped out on the refractory material covering the surface of the ceramic core (1).

8. The method for forming complex and compact cavity precision castings based on 3D printing ceramic cores according to claim 1, characterized in that: In step S1, when designing the three-dimensional model of the ceramic mold (1), reinforcing ribs (5) are provided according to the shrinkage variation law of the ceramic core (1) to prevent cracks from being generated during the molding and use of the ceramic core (1).

9. A casting, characterized in that: The method for forming complex and compact cavity precision castings based on 3D printing ceramic cores as described in any one of claims 1 to 8 is used for preparation.

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