A high-throughput method for the production of thin-walled castings

Abstract

The present application relates to the technical field of investment casting, in particular to a high-flux preparation method of thin-wall castings. The corundum plate with pre-pasted wax paper can form thin-wall cavities on both sides of the corundum plate, which is twice the number of low-melting-point metal sheets, and can double the efficiency. The corundum plate is beneficial to slurry hanging and sand spraying, and micro-cracks are not easy to appear during the shell preparation stage, and the metal liquid composition will not be contaminated. The molten metal liquid is subjected to super-temperature treatment and then poured into the shell, the super-temperature treatment can improve the fluidity of the molten metal liquid, improve the filling capacity, and the qualified rate is high, and the dendritic structure can also be refined to a certain extent.

Description

Technical Field

[0001] This invention relates to the field of investment casting technology, and specifically to a high-throughput method for preparing thin-walled castings. Background Technology

[0002] Investment casting is commonly used to produce high-temperature alloy precision castings, especially in the production of geometrically complex aerospace precision castings such as turbine blades for aircraft engines. The process involves coating a low-melting-point mold with a refractory material, drying and hardening it, then dewaxing and firing it to form a ceramic shell. Finally, molten alloy is poured into the shell, cooled, and the shell is removed to obtain the casting.

[0003] In the prior art, paraffin wax is usually used as a casting mold to prepare the mold shell. For example, Chinese patent CN201610245308.1 discloses a method for preparing a thin-walled sample of single crystal high-temperature alloy by precision casting. Although the surface state of the prepared thin-walled sample is consistent with the surface state of the actual thin-walled position of the air-cooled turbine blade, paraffin wax is very easy to deform during the preparation process, and the size of the casting is highly dependent on the mold, making it inconvenient to adjust the thickness and shape of the thin-walled sample as needed. To overcome the drawbacks of paraffin wax's easy deformation and high dependence on molds, existing technologies use low-melting-point metal sheets in the investment casting process. For example, Chinese patent CN202010660614.8 discloses a method for preparing ultra-thin-walled castings. However, this method has the following drawbacks: (1) A single low-melting-point metal sheet can only form a single thin-walled cavity, resulting in low efficiency; (2) During the shell-making process, the coating step requires spraying slurry onto the surface of the mold. Since the metal sheet is thin, the sidewalls are prone to uneven slurry application or even failure to completely coat the slurry during the slurry application and sand application. This leads to micro-cracks inside the shell, which in turn causes the shell to crack during the baking or pouring stages. After the molten metal is poured, it is easy for it to leak into the furnace cavity, thereby damaging the directional solidification equipment; (3) Metal residue is likely to contaminate the molten metal composition, limiting its practical application. Therefore, it is difficult to efficiently obtain high-quality thin-walled castings using existing investment casting components. Summary of the Invention

[0004] This invention provides a high-throughput preparation method for thin-walled castings. The invention uses a corundum plate with pre-attached wax paper to form thin-walled cavities on both sides of the corundum plate, which is twice as efficient as the same number of low-melting-point metal sheets. The corundum plate is also beneficial for slurry coating and sand pouring, and is less prone to micro-cracks during the shell-making stage, and will not contaminate the composition of the molten metal.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0006] This invention provides a high-throughput preparation method for thin-walled castings, comprising the following steps:

[0007] A casting mold assembly is provided, comprising a central support column, a gating system connected to the top of the central support column, a spiral crystal selector and a base connected to the bottom of the central support column, and an outer frame for fixing the gating system and the base; a plurality of corundum plates pre-attached with wax paper are fixedly connected to the side wall of the central support column; the spiral crystal selector comprises a spiral segment and a crystal-guiding segment connected sequentially from top to bottom; the top of the spiral segment is connected to the bottom of the central support column; the bottom of the crystal-guiding segment is connected to the base;

[0008] The investment molding assembly is sequentially subjected to wax impregnation, coating, sand application, drying, dewaxing, and firing to obtain the mold shell;

[0009] After the molten metal is subjected to overheating treatment, it is poured into the mold shell. After the molten metal solidifies in a specific direction, the shell is cleaned to obtain a thin-walled casting.

[0010] Preferably, the gating system includes a gating riser and a transition structure connected sequentially from top to bottom; the transition structure is connected to the central support column.

[0011] Preferably, the thickness of the corundum plate is 1 to 5 mm.

[0012] Preferably, the thickness of the waxed paper is 0.2 to 1 mm.

[0013] Preferably, each of the corundum plates is connected to the central support column via a slot.

[0014] Preferably, the temperature of the overheating treatment is 1600-1800℃, and the holding time is 5-30 minutes.

[0015] Preferably, the molten metal liquid is composed of a nickel-based single-crystal high-temperature alloy.

[0016] Preferably, the pouring temperature is 1480–1550°C.

[0017] Preferably, the directional solidification includes: after the shell containing molten metal is left to stand for 5 to 10 minutes, the shell is pulled out from the hot zone to the cold zone of the directional solidification equipment at a certain pulling speed to achieve directional solidification.

[0018] Preferably, the pulling speed is 3 to 6 mm / min.

[0019] This invention provides a high-throughput method for preparing thin-walled castings. The method uses a wax paper adhered to the surface of a corundum plate as a module, fixed to the side wall of a central support column. Due to the high strength of the corundum plate, the ductility of the adhered wax paper is ensured, thereby improving the surface finish of the thin-walled casting. This solves the problems of difficult mold design and manufacturing, high cost, and easy deformation of unsupported wax paper in traditional methods for preparing thin-walled castings. Furthermore, this invention allows for precise control of the dimensions of the thin-walled casting by controlling the shape and thickness of the wax paper, making it suitable for mass production of thin-walled castings and overcoming the low efficiency problem of traditional methods. Compared with existing methods for preparing thin-walled castings using low-melting-point metal sheets, this invention uses corundum plates pre-attached with wax paper, which improves efficiency. Wax paper can be attached to both sides of a single corundum plate, allowing for twice the number of cavities compared to metal sheets, thus doubling the efficiency. The pre-attached wax paper corundum plate is thicker, which facilitates slurry application and sand casting, reducing the likelihood of micro-cracks during the shell-making stage. The ceramic plate does not require demolding, solving the problem of incomplete removal of low-melting-point metal sheets during dewaxing and firing, providing a good foundation for subsequent molten metal pouring and directional solidification. Furthermore, the use of wax paper to construct the cavities offers advantages over low-melting-point metal sheets, including more thorough demolding, no low-melting-point metal residue during shell-making, and no contamination of the molten metal. The resulting thin-walled castings also have complete ceramic cavities and a high shell-forming rate.

[0020] This invention involves subjecting the molten metal to overheat treatment before pouring it into the mold shell. Overheat treatment can improve the fluidity of the molten metal, enhance the filling capacity, and result in a high yield rate. It can also refine the dendritic structure to a certain extent. Attached Figure Description

[0021] Figure 1 A schematic diagram of the casting mold assembly provided by the present invention; Figure 1 In the middle, 1 is the gating system riser, 2 is the transition structure of the gating system, 3 is the outer frame, 4 is the wax paper, 5 is the central support column, 6 is the corundum plate, 7 is the spiral section of the spiral crystal selector, 8 is the crystal pulling section of the spiral crystal selector, and 9 is the base.

[0022] Figure 2 This is a partial structural wireframe diagram of the casting mold assembly provided by the present invention;

[0023] Figure 3 This is an image of the casting assembly in Example 1;

[0024] Figure 4 A top view of the shell prepared in Example 1;

[0025] Figure 5 The front view of the shell prepared in Example 1;

[0026] Figure 6The image shows the cross-sectional microstructure of a 0.4 mm thick nickel-based single-crystal superalloy thin-walled casting prepared in Example 1 under an optical microscope.

[0027] Figure 7 The image shows the longitudinal section microstructure of a 1.0 mm thick nickel-based single-crystal superalloy thin-walled casting prepared in Example 1 under an optical microscope. Detailed Implementation

[0028] This invention provides a high-throughput preparation method for thin-walled castings, comprising the following steps:

[0029] A casting mold assembly is provided, comprising a central support column, a gating system connected to the top of the central support column, a spiral crystal selector and a base connected to the bottom of the central support column, and an outer frame for fixing the gating system and the base; a plurality of corundum plates pre-attached with wax paper are fixedly connected to the side wall of the central support column; the spiral crystal selector comprises a spiral segment and a crystal-guiding segment connected sequentially from top to bottom; the top of the spiral segment is connected to the bottom of the central support column; the bottom of the crystal-guiding segment is connected to the base;

[0030] The investment molding assembly is sequentially subjected to wax impregnation, coating, sand application, drying, dewaxing, and firing to obtain the mold shell;

[0031] After the molten metal is subjected to overheating treatment, it is poured into the mold shell. After the molten metal solidifies in a specific direction, the shell is cleaned to obtain a thin-walled casting.

[0032] This invention provides an investment casting assembly. In this invention, the investment casting assembly includes a central support column, a gating system connected to the top of the central support column, a spiral crystal selector and a base connected to the bottom of the central support column, and an outer frame for fixing the gating system and the base; a plurality of corundum plates pre-attached with wax paper are fixedly connected to the side wall of the central support column; the spiral crystal selector includes a spiral segment and a crystal-guiding segment connected sequentially from top to bottom; the top of the spiral segment is connected to the bottom of the central support column; the bottom of the crystal-guiding segment is connected to the base.

[0033] In this invention, the central support column, gating system, spiral crystal selector, base, and outer frame are preferably integrally formed by 3D printing; the material of the central support column, gating system, spiral crystal selector, base, and outer frame is preferably PSB powder (starch-based biodegradable material). This invention uses 3D printing technology to prepare the investment molding assembly consisting of the central support column, gating system, spiral crystal selector, base, and outer frame, eliminating the high cost of custom wax molds and reducing production costs.

[0034] The investment casting assembly provided by this invention includes a central support column for fixing and connecting pre-attached wax paper corundum plates. In this invention, a plurality of pre-attached wax paper corundum plates are fixedly connected to the side wall of the central support column. In this invention, when there are multiple pre-attached wax paper corundum plates, they are preferably evenly distributed on the outer side of the central support column. In this invention, each corundum plate is preferably connected to the central support column via a slot, specifically preferably: a number of grooves equal to the number of pre-attached wax paper corundum plates are pre-reserved on the outer periphery of the side wall of the central support column, the length and width of the grooves matching the height and thickness of the pre-attached wax paper corundum plates, and the depth of the grooves being sufficient to allow the pre-attached wax paper corundum plates to be inserted and fixed. In this invention, the longitudinal axis of the pre-attached wax paper corundum plate is preferably parallel to the central axis of the central support column. This invention does not have special requirements for the specific dimensions of the central support column; they can be determined according to the dimensions of the required thin-walled casting. In this invention, the thickness of the corundum plate is preferably 1-5 mm, more preferably 4 mm; the thickness of the wax paper is preferably 0.2-1 mm, more preferably 0.4-0.8 mm. In this invention, wax paper is preferably adhered to both sides of the corundum plate. In this invention, after molten metal is poured into the cavity formed by dewaxing, a thin-walled casting is obtained. This invention controls the forming quality of the thin-walled casting by controlling the shape and size of the wax paper. The fact that wax paper can be adhered to both sides of the corundum plate further improves production efficiency.

[0035] The investment casting assembly provided by this invention includes a gating system connected to the top of the central support column. In this invention, the gating system preferably includes a riser and a transition structure connected sequentially from top to bottom; the transition structure is connected to the central support column. As an embodiment of this invention, the transition structure consists of multiple transition unit plates; the upper part of each pre-attached wax paper corundum plate is held by two transition unit plates. In this invention, the transition structure is used to assist the central support column in fixing the pre-attached wax paper corundum plate in a slot, such as... Figure 2 As shown, to facilitate observation of the corundum plate's position, the transition structure is represented by a frame diagram and the solid is hidden. It can be seen that the internal corundum plate is fixed within the transition structure. After subsequent dewaxing, the transition structure forms a cavity for injecting molten metal, which helps improve the filling effect. In this invention, the diameter of the bottom of the gating system is preferably larger than the diameter of the central support column. This invention does not have special requirements for the specific structure of the gating system's gating system; a gating system structure well-known to those skilled in the art can be used.

[0036] The investment casting assembly provided by this invention includes a spiral crystal selector connected to the bottom end of the central support column. In this invention, the spiral crystal selector can better ensure the integrity of the single crystal in the thin-walled casting, resulting in a single-crystal thin-walled casting that meets the requirements. This invention does not impose any special limitations on the specific structure of the spiral crystal selector; any spiral crystal selector well-known to those skilled in the art can be used. In this invention, the spiral crystal selector includes a spiral segment and a crystal-drawing segment connected sequentially from top to bottom; the top end of the spiral segment is connected to the bottom of the central support column; and the bottom of the crystal-drawing segment is connected to a base. In this invention, when obtaining a single-crystal thin-walled casting, the spiral segment diameter of the spiral crystal selector is preferably 5 mm, and the spiral segment has preferably 1.5 turns; the crystal-drawing segment diameter of the spiral crystal selector is preferably 7 mm, and the length is preferably 30 mm.

[0037] The casting mold assembly provided by this invention includes a base connected to the bottom support of the spiral crystal selector. The base supports the entire casting mold module and is connected to the spiral crystal selector and the outer frame. In this invention, the height of the base is preferably 5 mm, and the diameter is preferably 72 mm.

[0038] The investment casting assembly provided by this invention includes an outer frame that secures the gating system and the base. Preferably, the outer frame includes components that are fixedly connected to the base and extend to both sides that are fixedly connected to the gating system and riser. In this invention, the base and the outer frame are used to securely support other structures within the investment casting assembly.

[0039] As an embodiment of the present invention, the casting assembly provided by the present invention is as follows: Figure 1 As shown, the system includes a central support column, a gating system connected to the top of the central support column, a spiral crystal selector and a base connected to the bottom of the central support column, and an outer frame for fixing the gating system and the base. Several corundum plates pre-attached with wax paper are fixedly connected to the side walls of the central support column. The spiral crystal selector includes a spiral segment and a crystal-guiding segment connected sequentially from top to bottom. The top of the spiral segment is connected to the bottom of the central support column. The bottom of the crystal-guiding segment is connected to the base. The gating system includes a riser and a transition structure connected sequentially from top to bottom. The outer frame is connected to both sides of the base, and the outer frame extends to both sides of the riser and the gating system.

[0040] After obtaining the investment mold assembly, the present invention sequentially performs wax impregnation, coating, sand application, drying, dewaxing, and firing to obtain a mold shell. The present invention does not have special requirements for the specific methods of wax impregnation, coating, sand application, drying, dewaxing, and firing; processes well-known to those skilled in the art can be used. The present invention preferably uses a traditional ceramic mold shell manufacturing process to produce a ceramic mold shell from the investment mold assembly. In the present invention, wax impregnation can solve the problems of low strength, low density, and poor surface roughness in investment mold assemblies prepared by rapid prototyping methods. In a specific embodiment of the present invention, a first coating is preferably applied, using zircon powder + cobalt aluminate + silica sol, followed by a first sanding process with 120# zircon sand, and then a first drying process. A second coating is then applied, using fused silica powder + silica sol, followed by a second sanding process with 46# corundum sand, and then a second drying process. A third coating is then applied, using fused silica powder + silica sol, followed by a third sanding process with 35S mullite sand, and then a third drying process. A fourth coating is then applied, using EC95 powder + silica sol, followed by a fourth sanding process and then a fourth drying process. Subsequent layers are the same as the fourth layer, and the coating, sanding, and drying steps are repeated until a coating of suitable thickness is obtained. In this invention, the total number of coating layers is preferably eight, and the eighth layer is only coated, without sanding. In this invention, the dewaxing and firing processes are performed using a common shell-making method to obtain a shell with sufficient strength.

[0041] After obtaining the mold shell, the present invention involves superheating the molten metal and then pouring it into the mold shell. After the molten metal solidifies directionally, the shell is cleaned to obtain a thin-walled casting. In the present invention, the composition of the molten metal is preferably a nickel-based single-crystal high-temperature alloy. In the present invention, the preferred method for preparing the molten metal is to perform vacuum melting of the master alloy to obtain the molten metal. In the present invention, the vacuum melting preferably includes: placing the master alloy in a magnesium oxide ceramic crucible and melting it under vacuum conditions using a medium-frequency induction heating device to obtain the molten metal.

[0042] In this invention, the temperature of the overheating treatment is preferably 1600-1800℃, and the holding time is preferably 5-30 min.

[0043] In this invention, the casting temperature is preferably 1480–1550°C, more preferably 1520–1550°C. In this invention, the casting is preferably performed under vacuum conditions, using a three-stage vacuum system consisting of a mechanical pump, a Roots pump, and an oil diffusion pump to obtain the required vacuum environment. The vacuum level is preferably 6 × 10⁻⁶. -2 Below Pa.

[0044] In this invention, the directional solidification preferably includes: after the shell containing molten metal has been left to stand for 5-10 minutes, the shell is pulled out from the hot zone to the cold zone of the directional solidification equipment at a certain pulling rate to achieve directional solidification. In this invention, the hot zone is preferably the hot zone of a holding furnace; the cold zone is preferably a lower-cavity cold zone. In this invention, the pulling rate is preferably 3-6 mm / min, more preferably 4-6 mm / min. In this invention, the casting and directional solidification are preferably carried out in a directional solidification equipment, preferably a 2 kg dual-zone graphite resistance-heated Bridgman high-gradient directional solidification furnace. Preferably, after directional solidification, cooling is performed before shell cleaning.

[0045] The present invention does not impose any special limitations on the specific shell cleaning process. Any shell cleaning process known to those skilled in the art can be used, as long as excessive stress is avoided as much as possible.

[0046] The high-throughput preparation method for thin-walled castings provided by this invention overcomes the obstacle of traditional production processes that rely on expensive molds for preparing single-crystal thin-walled castings, significantly reducing costs. Furthermore, the size and shape of the thin-walled castings can be precisely controlled according to the size and shape of the wax paper. This invention allows adjustment of the number of thin-walled castings by increasing or decreasing the number of corundum plates with pre-attached wax paper in the investment casting module, and control of the size and shape of the wax paper through stacking. Multiple thin-walled castings of different sizes and shapes can be successfully prepared in a single experiment, greatly improving production efficiency.

[0047] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0048] Example 1

[0049] PSB powder is used to create a model through 3D printing, such as... Figure 1 As shown, it consists of a central support column, a gating system, a spiral crystal selector, a base, and an outer frame. Four corundum plates, each 100mm long, 20mm wide, and 1mm thick, are inserted into the side wall grooves of the central support column. Wax paper, each 100mm long, 20mm wide, and 0.4mm, 0.6mm, 0.8mm, and 1.0mm thick, is pre-attached to the sides of each of the four corundum plates. These are then assembled with the model to form a casting mold assembly, as shown. Figure 3 As shown;

[0050] The investment molding assembly is sequentially subjected to wax impregnation, coating, sand application, drying, dewaxing, and firing to obtain a mold shell. The top and front views of the mold shell are shown below. Figure 4 , 5 As shown;

[0051] The vacuum melting, overheating treatment, inverted casting, and directional drawing process of nickel-based single-crystal superalloys were completed using a 2 kg dual-zone graphite resistance-heated Bridgman high-gradient directional solidification furnace. The DD403 master alloy with the composition shown in Table 1 was vacuum melted. The resulting DD403 alloy liquid was then overheated and poured into the mold shell at a vacuum degree of 1.8 × 10⁻⁶. -2 Pa, the overheating temperature is 1600℃, the holding time is 20min, the pouring temperature is 1520℃, the DD403 alloy liquid is left to stand in the mold shell for 10min, the mold shell is pulled out at a uniform speed of 6mm / min, after the directional solidification is completed, the mold shell is cleaned to obtain a nickel-based single crystal high temperature alloy thin-walled casting.

[0052] Table 1. Chemical composition (mass percentage) of DD403 master alloy

[0053]

[0054] Figure 6 This is a cross-sectional microstructure image of a 0.4 mm thick nickel-based single-crystal superalloy thin-walled casting observed under an optical microscope. Figure 7 This is a cross-sectional microstructure image of a 1.0 mm thick nickel-based single-crystal superalloy thin-walled casting, observed under an optical microscope. Figures 6-7 It can be seen that the dendrites of the thin-walled sample are arranged in a regular manner, and there are no obvious solidification defects in the microstructure, that is, the single crystal integrity is good.

[0055] Compared with Chinese patent CN201610245308.1, this invention does not require high-value-added molds, which is beneficial for repeated modifications to the structure of thin-walled castings without excessive mold design and manufacturing costs. Compared with Chinese patents CN201210136757.4, CN202010222079.8 and CN202010258519.5, this invention, in terms of structural design, can meet the requirement of using only one seed crystal to prepare several single-crystal thin-walled castings, and can optimize the primary orientation deviation of single-crystal thin-walled castings by decomposing the orientation deviation in three-dimensional space into orientation deviations in the thickness and width directions on two two-dimensional planes, and the degree of deviation is reduced after decomposition.

[0056] Example 2

[0057] PSB powder is used to create a model through 3D printing, such as... Figure 1As shown, it consists of a central support column, a gating system, a spiral crystal selector, a base, and an outer frame. Four corundum plates, each 100mm long, 20mm wide, and 4mm thick, are inserted into the side wall grooves of the central support column. Wax paper, each 100mm long, 20mm wide, and 0.2mm thick, is pre-attached to both sides of the corundum plates. The corundum plates with the wax paper attached are then assembled with the model to form a casting mold assembly.

[0058] The investment molding assembly is sequentially subjected to wax impregnation, coating, sand application, drying, dewaxing, and firing to obtain the mold shell;

[0059] The vacuum melting, overheating treatment, inverted casting, and directional drawing processes of nickel-based single-crystal superalloys were completed using a 2 kg dual-zone graphite resistance-heated Bridgman high-gradient directional solidification furnace. The DD403 master alloy with the composition shown in Table 1 was vacuum melted. The resulting DD403 alloy liquid was then overheated and poured into the mold shell at a vacuum degree of 2.1 × 10⁻⁶. -2 Pa, the overheating temperature is 1800℃, the holding time is 5min, the pouring temperature is 1480℃, the DD403 alloy liquid is left to stand in the shell for 5min, the shell is pulled out at a uniform speed of 6mm / min, the shell after directional solidification is cleaned to obtain a nickel-based single crystal high temperature alloy thin-walled casting.

[0060] Compared to the method used in Chinese Patent CN202010660614.8 to form cavities for preparing thin-walled castings using low-melting-point metal sheets, this invention utilizes corundum plates pre-attached with wax paper, resulting in better wettability and improved filling capacity. Furthermore, the same number of corundum plates can have wax paper attached to both sides, and the number of cavities formed is twice that of low-melting-point metal sheets. This invention can double the production efficiency of thin-walled castings, achieving relatively high production efficiency and meeting the process requirements of high-throughput experiments.

[0061] Example 3

[0062] The preparation method is basically the same as that in Example 1, except that the temperature of the overheating treatment is adjusted to 1700°C.

[0063] Example 4

[0064] The preparation method is basically the same as that in Example 1, except that the temperature of the overheating treatment is adjusted to 1800°C.

[0065] Test case

[0066] The viscosity values ​​of the DD403 alloy liquid after the above-mentioned overheat treatment were tested in Examples 1 and 3-4. As the overheat treatment temperature increased from 1600℃ to 1800℃, the viscosity value of the DD403 alloy liquid decreased from 46.4 mPa·s to 34.1 mPa·s, which enhanced the fluidity of the alloy liquid and further improved the filling capacity of thin-walled castings.

[0067] The degree of dendrite spacing refinement of the 0.8 mm thick nickel-based single-crystal superalloy thin-walled castings prepared in Examples 1 and 3-4 is shown in Table 2.

[0068] Table 2 Dendrite spacing at different overheating temperatures

[0069]

[0070] As can be seen from Table 2, overtemperature treatment can refine the dendritic structure to a certain extent.

[0071] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A high-throughput preparation method for thin-walled castings, comprising the following steps: A casting mold assembly is provided, comprising a central support column, a gating system connected to the top of the central support column, a spiral crystal selector and a base connected to the bottom of the central support column, and an outer frame for fixing the gating system and the base; a plurality of corundum plates pre-attached with wax paper are fixedly connected to the side wall of the central support column; the spiral crystal selector comprises a spiral segment and a crystal-guiding segment connected sequentially from top to bottom; the top of the spiral segment is connected to the bottom of the central support column; the bottom of the crystal-guiding segment is connected to the base; The investment molding assembly is sequentially subjected to wax impregnation, coating, sand application, drying, dewaxing, and firing to obtain the mold shell; After the molten metal is subjected to overheating treatment, it is poured into the mold shell. After the molten metal solidifies in a specific direction, the shell is cleaned to obtain a thin-walled casting. The thickness of the corundum plate is 1~5mm; The thickness of the waxed paper is 0.2~1mm; The temperature for the overheating treatment is 1600~1800℃, and the holding time is 5~30min.

2. The high-throughput preparation method according to claim 1, characterized in that, The gating system includes a gating riser and a transition structure connected sequentially from top to bottom; the transition structure is connected to the central support column.

3. The high-throughput preparation method according to claim 1, characterized in that, Each of the corundum plates is connected to the central support column via a slot.

4. The high-throughput preparation method according to claim 1, characterized in that, The molten metal liquid is composed of a nickel-based single-crystal high-temperature alloy.

5. The high-throughput preparation method according to claim 4, characterized in that, The pouring temperature is 1480~1550℃.

6. The high-throughput preparation method according to claim 1, characterized in that, The directional solidification includes: after the mold shell filled with molten metal is left to stand for 5 to 10 minutes, the mold shell is pulled out from the hot zone to the cold zone of the directional solidification equipment at a certain pulling speed to achieve directional solidification.

7. The high-throughput preparation method according to claim 6, characterized in that, The pulling speed is 3~6 mm / min.

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