A shrouded single crystal blade casting wax pattern and casting method

Abstract

The application relates to a single-crystal blade casting wax mould with a crown and a casting method, wherein the wax mould comprises a blade wax mould, a selector wax mould and a pouring system wax mould, the selector wax mould is connected with the blade wax mould, the base of the pouring system wax mould is connected with the selector wax mould through a supporting part, the top surface of the supporting part is an inclined plane and forms an angle with the top surface of the base, the axis perpendicular to the top surface of the supporting part is parallel to the blade stacking axis of the blade wax mould, and the axis of the seeding section of the selector wax mould is perpendicular to the base plane. According to the scheme, the inclined top surface of the supporting part and the inclined blade stacking axis of the blade wax mould are arranged, so that the blade can be kept in the inclined arrangement during the casting forming process, the single-crystal blade orientation and the blade stacking axis deviation can be less than 10 DEG, and the formation of mixed crystals at the "low point" of the rim plate can be avoided. Meanwhile, the blade rim plate itself can form better upper-layer feeding for lower-layer feeding, the last "high point" is connected with the riser, the last solidification position is transferred to the riser, and the rim plate porosity can be avoided.

Description

Technical Field

[0001] This invention relates to the technical field of single-crystal blade preparation, and more specifically, to a wax model for casting crowned single-crystal blades and a casting method thereof. Background Technology

[0002] Turbine blades at the hot end of an aero-engine are crucial components for increasing turbine inlet temperature and improving engine performance. Currently, precision casting is the mainstream method for producing aero-engine turbine blades. The process is as follows: a special wax material is injected into a mold to obtain a blade wax model; multiple layers of refractory slurry are repeatedly coated onto the wax model surface, and the wax material is removed to obtain a mold shell; molten metal is poured into the inner cavity of the mold shell to obtain a casting; finally, the surface of the mold shell is cleaned, polished, and inspected to obtain the finished blank. However, with the continuous increase in the thrust-to-weight ratio of aero-engines, turbine blades have undergone a transformation in grain structure from equiaxed to oriented to single-crystal to adapt to the gradually increasing inlet temperature. Single-crystal blades, by eliminating grain boundaries—a weak point at high temperatures—significantly improve their heat resistance and creep resistance, and have become an indispensable core component of modern advanced aero-engines.

[0003] Crowned blades are a common type of single-crystal blade, typically composed of a tenon, inner edge plate, blade body, and outer edge plate. Because single-crystal blades require the blade stacking axis (i.e., the principal stress direction) to be close to the crystallographic direction of the single crystal to fully utilize its optimal mechanical properties, conventional crowned single-crystal blades are cast and solidified in a "birdcage" gating system with the blade stacking axis parallel to the vertical direction. However, in this case, the blade edge plate gating surface is essentially horizontal, and the upper surface of the horizontally positioned edge plate becomes the last area to solidify, making liquid phase feeding difficult and inevitably resulting in micro-porosity or shrinkage cavities. Furthermore, regardless of whether the outer edge plate is placed upwards or downwards, the tendency for porosity on the upper surface of the edge plate cannot be fundamentally eliminated because the edge plate plane is always perpendicular to the temperature gradient direction (i.e., horizontal orientation). These porosity defects severely reduce the high-cycle fatigue life and high-temperature oxidation resistance of the blade. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of existing technologies in which micro-porosity or shrinkage defects are generated on the surface of the blade during the solidification process. This invention provides a wax model and casting method for crowned single-crystal blades. The blades prepared by this method will not have micro-porosity or shrinkage defects on the surface of the blade, thereby improving the yield and reliability of the blades during use.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A crowned single-crystal blade casting wax model is provided, comprising a blade wax model, a crystal selector wax model, and a gating system wax model. The top surface of the crystal selector wax model is connected to the blade wax model. The base of the gating system wax model is connected to the crystal selector wax model via a support portion disposed on the surface of the base. The top surface of the support portion is connected to the bottom surface of the crystal selector wax model. The top surface of the support portion is an inclined plane and forms an angle with the top surface of the base. The axis Q perpendicular to the top surface of the support portion is parallel to the blade stacking axis P of the blade wax model. The crystal-leading segment axis M of the crystal selector wax model is perpendicular to the plane of the base.

[0006] The crowned single-crystal blade casting wax model in this design keeps the blade tilted during casting, allowing the solid-liquid two-phase region to smoothly cover the entire rim plate, including the lowest point, thus preventing the growth of disordered fine grains at low points due to localized overcooling. In this design, the bottom surface of the support is located on the top surface of the base.

[0007] Simultaneously, the tilted blade edge creates a height difference. During solidification, the molten metal, influenced by gravity, flows from higher to lower areas. After tilting, the area on the edge furthest from the riser (the lowest point) solidifies first from the tenon towards the lowest point through the designed rounded corners, while the area closer to the riser (the highest point) solidifies last. The edge itself forms an "upper layer feeding the lower layer." The lower layer, closer to the bottom of the casting cavity, solidifies first to form a dense layer; the upper layer, closer to the riser, remains liquid, filling the void created by shrinkage in the lower layer through gravity. This effectively establishes a "top-down" feeding direction within the edge. Directly connecting the highest point of the edge to the riser via a gating system or feeding channel ensures that the last solidified part of the edge is precisely the "highest point" connected to the riser. When the high point shrinks, the molten metal in the riser can immediately flow in, filling the volume gap. This achieves the goal of transferring the final solidification location to the riser. At this point, the solidification sequence of the entire flange and other parts of the blade is: the far end of the flange (lowest point) → the end of the flange near the riser (highest point) → the riser itself. Ultimately, all shrinkage defects are "driven" into the riser. After removing the riser, the interior of the flange becomes dense and free of looseness.

[0008] This design, using a crowned single-crystal blade casting wax model, ensures the blade remains tilted during casting through the inclined top surface of the support and the inclined blade stacking axis of the wax model. This achieves a deviation of less than 10° between the single-crystal blade orientation and the blade stacking axis. The solid-liquid two-phase region can then smoothly extend to the "low point" of the blade edge plate through the designed rounded corners, preventing the formation of impurities at the edge plate's "low point." Simultaneously, due to the blade's tilted design, the blade edge plate itself can form a better upper-layer feeding layer, and the final "high point" connects with the riser, transferring the final solidification location to the riser and preventing the edge plate from becoming porous.

[0009] Furthermore, there are multiple support parts, which are equidistantly arranged in a circle around the axis N of the base. On the plane of the base, a counterclockwise or clockwise rotation direction is defined as the positive direction around the axis N. The distance from the end of the top surface of the support part away from the positive direction to the top surface of the base is greater than the distance from the end of the top surface of the support part closer to the positive direction to the top surface of the base. With multiple support parts, each connected to a crystal selector wax model, multiple blades can be cast simultaneously, further improving the casting efficiency. Simultaneously, the inclined direction of the top surface of the support parts ensures that the orientation of the formed blades is tangential to the circumferential direction of the wax model base of the gating system. This results in a larger horizontal projection of the blades onto the base with a larger tangential span and a smaller radial span. In the field of directional solidification precision casting, the module is heated by an external graphite induction heater. The heating rate in the middle of the module is slower than that at the outside. After the module reaches the predetermined temperature, it is moved downwards and pulled on the spindle, moving the blades from the heating area of ​​the graphite induction heater to the cooling area of ​​the water-cooled copper ring. The blades, oriented tangentially to the circumferential direction of the wax pattern base in the gating system, maintain a relatively constant distance from the water-cooling ring during the pulling process, resulting in more stable radiative heat transfer conditions and a more stable temperature field.

[0010] Furthermore, the acute angle between the axis Q perpendicular to the top surface of the support and the axis N of the base is 5°-20°. When the angle is too small, looseness and pores will still exist on the blade; when the angle is too large, it easily leads to blade deformation and a reduction in the blade's temperature gradient. Experiments have shown that the blade yield is highest when the angle is between 5° and 20°. The specific angle can be adjusted according to the blade's size and material.

[0011] Furthermore, both the top and bottom surfaces of the support are circular. The rotational symmetry of the two circular end faces of the support ensures that the heat flow is vertically upward and the grain orientation is concentrated. The absence of sharp corners in the circular shape avoids stress concentration and the formation of impurities. In addition, the circular top surface of the support can perfectly match the circular crystal selector.

[0012] Furthermore, the projection of the top surface of the support onto the top surface of the base is tangent to the bottom surface of the support. The projection of the top surface of the support onto the top surface of the base is tangent to the bottom surface of the support, meaning the horizontal projection of the lowest point of the top surface of the support lies on the horizontal projection of the bottom surface of the support; that is, the perpendicular line passing through the lowest point of the top surface of the support lies on the side wall of the support. At this point, when the wax mold is demolded axially, no undercut will form in any area because every part is "visible" from directly above, and the mold core can be pulled directly upwards, avoiding undercuts.

[0013] Furthermore, the number of support parts is 6-16. Having 6-16 support parts means that 6-16 blades can be cast at once. A larger number requires a larger base, while a smaller number results in lower production efficiency per batch. Preferably, it is 6-16 support parts. The appropriate number of support parts can be selected based on the actual blade size; generally, a gating system base with 6 support parts is preferred.

[0014] Furthermore, the sprue cup of the wax model in the gating system is connected to the top of the blade wax model via a transverse runner. There are multiple transverse runners, each connected to a riser at the top of one of the blade wax models.

[0015] The present invention also provides a method for casting crowned single-crystal blades, comprising the following steps: Step 1: Prepare and assemble the wax model assembly: After the wax model assembly is assembled, it becomes the above-mentioned crowned single crystal blade casting wax model; Step 2, Shell Making: The wax mold assembly is subjected to investment casting to form a ceramic shell; Step 3: Dewaxing: The ceramic shell is heated to remove the wax mold, resulting in a ceramic shell with a cavity; Step 4, Casting: Preheat the ceramic mold shell with cavity and assemble it onto the cooling copper plate. After assembly, pour in molten metal and obtain the casting by crystal pulling through directional solidification process. Step 5, Cleaning: After the casting cools, remove the ceramic shell to obtain the casting containing the gating system, risers, and blades; Step 6: Cutting: Cut the blade casting from the gating system and remove the top riser structure to obtain a crowned single-crystal blade.

[0016] Preferably, in step four, the upper surface of the cooling copper disk has a protrusion with the same shape as the support portion. When the mold shell is assembled onto the cooling copper disk, the protrusion extends into the inner cavity of the mold shell and fits against the mold shell. The cooling copper disk is a water-cooled copper disk. The protrusion and the support portion have the same shape, so that the inner cavity formed by the support portion at the bottom of the mold shell can be smoothly fitted onto the protrusion, and a positional relationship of tight fit between the protrusion and the side wall of the inner cavity of the mold shell is achieved after fitting the protrusion. Generally, the size of the protrusion on the cooling copper disk is 0.5% smaller than the size of the support portion, so that the protrusion can smoothly extend into the mold shell. The inclined top surface of the protrusion serves as the contact surface between the molten metal and the cooling copper disk. The contact surface is planar, and the columnar crystals crystallized through the planar surface will have a more concentrated orientation, so as to obtain accurately oriented single-crystal blades.

[0017] Preferably, in step two, the investment casting shell-making process includes multiple dip coatings with refractory slurry, sprinkling with refractory sand, and drying and hardening.

[0018] The present invention discloses a method for casting crowned single-crystal blades. By setting the top surface of the inclined support portion in the wax pattern structure, the blade is inclined, which allows the solid-liquid two-phase region to spread smoothly to the "low point" of the blade edge plate, avoiding the formation of impurity crystals at the "low point" of the edge plate. At the same time, due to the inclined setting of the blade, the blade edge plate itself can form a better upper feeding lower layer, and the final "high point" connects with the riser, transferring the final solidification position to the riser and avoiding loose edge plate.

[0019] Compared with the prior art, the beneficial effects of the present invention are: This scheme's crowned single-crystal blade casting wax model and casting method, through the inclined top surface of the support and the inclined blade stacking axis of the blade wax model, ensures that the blade maintains its inclined position during the casting process, achieving the requirement that the deviation between the single-crystal blade orientation and the blade stacking axis is less than 10°. At this time, the solid-liquid two-phase region can smoothly spread to the "low point" of the blade edge plate through the designed rounded corners, avoiding the formation of impurity crystals at the "low point" of the edge plate. At the same time, due to the inclined position of the blade, the blade edge plate itself can form a better upper feeding lower layer, and the final "high point" connects with the riser, transferring the final solidification position to the riser and avoiding loose edge plate.

[0020] In a crowned single-crystal blade casting method of the present invention, the cooling copper disk uses a raised inclined top surface as the contact surface between the molten metal and the cooling copper disk. The contact surface is a plane, and the columnar crystals formed by plane crystallization will have a more concentrated orientation, so as to obtain a single-crystal blade with accurate orientation. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of a crowned single-crystal blade casting wax model according to the present invention; Figure 2 This is a schematic diagram of the base of a crowned single-crystal blade casting wax mold according to the present invention; Figure 3 This is a schematic diagram of the base of a crowned single-crystal blade casting wax mold from another angle, according to the present invention. The arrow in the diagram points in the positive direction. Figure 4 This is a flowchart of a crowned single-crystal blade casting method according to the present invention.

[0022] In the attached diagram: 1. Wax model of blade; 2. Wax model of crystal selector; 3. Base; 301. Support part; 4. Sprue cup; 5. Horizontal runner. Detailed Implementation

[0023] The present invention will be further described below with reference to specific embodiments. The accompanying drawings are for illustrative purposes only, representing schematic diagrams rather than actual physical objects, and should not be construed as limiting the scope of this patent. To better illustrate the embodiments of the present invention, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0024] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0025] Example 1 This embodiment is a first embodiment of a wax mold for casting crowned single-crystal blades, as follows: Figure 1-3 As shown, the system includes a blade wax model 1, a crystal selector wax model 2, and a gating system wax model. The top surface of the crystal selector wax model 2 is connected to the blade wax model 1. The base 3 of the gating system wax model is connected to the crystal selector wax model 2 via a support part 301 provided on the surface of the base 3. The top surface of the support part 301 is connected to the bottom surface of the crystal selector wax model 2. The top surface of the support part 301 is an inclined plane and forms an angle with the top surface of the base 3. The axis Q perpendicular to the top surface of the support part 301 is parallel to the blade stacking axis P of the blade wax model 1. The axis M of the crystal-leading section of the crystal selector wax model 2 is perpendicular to the plane of the base 3. The bottom surface of the support part 301 is located on the top surface of the base 3.

[0026] The working principle of this embodiment is as follows: In this embodiment, the crowned single-crystal blade casting wax mold keeps the blade tilted during the casting process. During the casting process, the solid-liquid two-phase region can smoothly cover the entire rim plate, including the lowest position of the rim plate, thereby avoiding the growth of messy fine grains at the low point due to local overcooling.

[0027] Simultaneously, the tilted blade edge creates a height difference. During solidification, the molten metal, influenced by gravity, flows from higher to lower areas. After tilting, the area on the edge furthest from the riser (the lowest point) solidifies first from the tenon towards the lowest point through the designed rounded corners, while the area closer to the riser (the highest point) solidifies last. The edge itself forms an "upper layer feeding the lower layer." The lower layer, closer to the bottom of the casting cavity, solidifies first to form a dense layer; the upper layer, closer to the riser, remains liquid, filling the void created by shrinkage in the lower layer through gravity. This effectively establishes a "top-down" feeding direction within the edge. Directly connecting the highest point of the edge to the riser via a gating system or feeding channel ensures that the last solidified part of the edge is precisely the "highest point" connected to the riser. When the high point shrinks, the molten metal in the riser can immediately flow in, filling the volume gap. This achieves the goal of transferring the final solidification location to the riser. At this point, the solidification sequence of the entire flange and other parts of the blade is: thin-walled section → far end of flange (lowest point) → near-rise end of flange (highest point) → riser itself. Ultimately, all shrinkage defects are "driven" into the riser. After removing the riser, the interior of the flange becomes dense and free of looseness.

[0028] The beneficial effects of this embodiment are as follows: In this embodiment, the crowned single-crystal blade casting wax model, through the inclined top surface of the support 301 and the inclined blade stacking axis of the blade wax model 1, ensures that the blade remains inclined during the casting process, achieving the requirement that the deviation between the single-crystal blade orientation and the blade stacking axis is less than 10°. At this time, the solid-liquid two-phase region can smoothly spread to the "low point" of the blade edge plate through the designed rounded corners, avoiding the formation of impurities at the "low point" of the edge plate. At the same time, due to the inclined setting of the blade, the blade edge plate itself can form a better upper feeding lower layer, and the final "high point" connects with the riser, transferring the final solidification position to the riser and avoiding loose edge plate.

[0029] Example 2 This embodiment is a second embodiment of a wax mold for casting crowned single-crystal blades, such as... Figure 1-3 As shown, this embodiment further defines the structure of the wax model based on Embodiment 1.

[0030] Specifically, there are multiple support parts 301, which are arranged equidistantly in a circle on the base 3 with the axis N of the base 3 as the center. On the plane of the base 3, the counterclockwise rotation direction with the axis N of the base 3 as the center is set as the positive direction. The distance from the end of the top surface of the support part 301 away from the positive direction to the top surface of the base 3 is greater than the distance from the end of the top surface of the support part 301 closer to the positive direction to the top surface of the base 3. Preferably, there are 6-16 support parts 301, and each support part 301 is connected to a crystal selector wax mold 2.

[0031] Specifically, the acute angle between the axis Q perpendicular to the top surface of the support 301 and the axis N of the base 3 is 5°-20°.

[0032] Specifically, both the top and bottom surfaces of the support portion 301 are circular. The projection of the top surface of the support portion 301 onto the top surface of the base 3 is tangent to the bottom surface of the support portion 301.

[0033] Specifically, the sprue cup 4 of the gating system wax model is connected to the top of the blade wax model 1 via a transverse runner 5. There are multiple transverse runners 5, and each transverse runner 5 is connected to a riser at the top of a blade wax model 1.

[0034] The beneficial effects of this embodiment are as follows: Multiple support sections 301 are provided, allowing for the simultaneous casting of multiple blades and further improving casting efficiency. Blades positioned tangentially to the circumferential direction of the wax pattern base 3 of the gating system maintain a relatively constant distance from the water-cooling ring during the pulling process, resulting in more stable radiative heat transfer and a more stable temperature field. The blade yield is highest when the angle between axis Q and axis N is between 5° and 20°. The rotational symmetry of the two circular end faces of support section 301 ensures vertical upward heat flow and concentrated grain orientation. The absence of sharp corners in the circular shape prevents stress concentration and the formation of impurities. Furthermore, the circular top surface of support section 301 perfectly matches the circular crystal selector. When the projection of the top surface of support section 301 onto the top surface of base 3 is tangent to the bottom surface of support section 301, the mold core can be directly pulled upwards, avoiding undercutting.

[0035] Example 3 This embodiment is an example of a method for casting crowned single-crystal blades, such as... Figure 4 As shown, it includes the following steps: Step 1: Preparation and assembly of wax model components: After the wax model components are assembled, a crowned single-crystal blade casting wax model is shown in Example 2; Step 2, Shell Making: The wax model assembly undergoes investment casting to form a ceramic shell; this includes multiple applications of refractory slurry, sprinkling with refractory sand, and drying and hardening. Step 3, Dewaxing: The ceramic shell is heated to remove the wax mold, resulting in a ceramic shell with a cavity; Step 4, Casting: Preheat the ceramic mold shell with cavity and assemble it onto the cooling copper plate. After assembly, pour in molten metal and obtain the casting by crystal pulling through directional solidification process. Step 5, Cleaning: After the casting cools, remove the ceramic shell to obtain the casting containing the gating system, risers, and blades; Step 6: Cutting: Cut the blade casting from the gating system and remove the top riser structure to obtain a crowned single-crystal blade.

[0036] Specifically, in step four, the upper surface of the cooling copper plate has a protrusion with the same shape as the support. When the mold shell is assembled onto the cooling copper plate, the protrusion extends into the inner cavity of the mold shell and fits against the mold shell. Generally, the size of the protrusion on the cooling copper plate is 0.5% smaller than the size of the support, so that the protrusion can smoothly extend into the mold shell.

[0037] Specifically, in step two, the investment casting shell-making process includes multiple dip coatings of refractory slurry, sprinkling of refractory sand, and drying and hardening.

[0038] The beneficial effects of this embodiment are as follows: The crowned single-crystal blade casting method of this embodiment achieves an inclined blade design by setting the top surface of the inclined support portion 301 in the wax pattern structure. This allows the solid-liquid two-phase region to smoothly spread to the "low point" of the blade edge plate, avoiding the formation of impurity crystals at the "low point" of the edge plate. Simultaneously, due to the inclined blade design, the blade edge plate itself can form a better upper-layer feeding layer, and the final "high point" connects with the riser, transferring the final solidification position to the riser and preventing the edge plate from becoming loose. The protrusion and support portion have the same shape, allowing the inner cavity formed by the support portion at the bottom of the mold shell to be smoothly fitted onto the protrusion, achieving a tight fit between the protrusion and the inner wall of the mold shell after fitting. The inclined top surface of the protrusion serves as the contact surface between the molten metal and the cooling copper disk. Since the contact surface is planar, the columnar crystals formed by planar crystallization will have a more concentrated orientation, facilitating the acquisition of accurately oriented single-crystal blades.

[0039] In the specific implementation of the above embodiments, the technical features can be combined in any non-contradictory way. For the sake of brevity, not all possible combinations of the above technical features are described. However, as long as the combination of these technical features is not contradictory, it should be considered to be within the scope of this specification.

[0040] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A wax model for casting a crowned single-crystal blade, comprising a blade wax model (1), a crystal selector wax model (2), and a gating system wax model, wherein the top surface of the crystal selector wax model (2) is connected to the blade wax model (1), characterized in that, The base (3) of the casting system wax model is connected to the crystal selector wax model (2) through a support (301) provided on the surface of the base (3). The top surface of the support (301) is connected to the bottom surface of the crystal selector wax model (2). The top surface of the support (301) is an inclined plane and forms an angle with the top surface of the base (3). The axis Q perpendicular to the top surface of the support (301) is parallel to the blade stacking axis P of the blade wax model (1). The crystal-leading segment axis M of the crystal selector wax model (2) is perpendicular to the plane of the base (3).

2. The wax model for casting a crowned single-crystal blade according to claim 1, characterized in that, There are multiple support parts (301), and the multiple support parts (301) are arranged equidistantly in a circle on the base (3) with the axis N of the base (3) as the center. On the plane of the base (3), the counterclockwise or clockwise rotation direction with the axis N of the base (3) as the center is set as the positive direction. The distance from the end of the top surface of the support part (301) away from the positive direction to the top surface of the base (3) is greater than the distance from the end of the top surface of the support part (301) close to the positive direction to the top surface of the base (3).

3. The wax model for casting a crowned single-crystal blade according to claim 2, characterized in that, The acute angle between the axis Q perpendicular to the top surface of the support (301) and the axis N of the base (3) is 5°-20°.

4. The wax model for casting a crowned single-crystal blade according to claim 3, characterized in that, The top and bottom surfaces of the support (301) are both circular.

5. The wax model for casting a crowned single-crystal blade according to claim 4, characterized in that, The projection of the top surface of the support (301) onto the top surface of the base (3) is tangent to the bottom surface of the support (301).

6. A wax model for casting a crowned single-crystal blade according to any one of claims 2-5, characterized in that, The pouring cup (4) of the wax mold of the gating system is connected to the riser at the top of the blade wax mold (1) through the transverse runner (5).

7. A wax model for casting a crowned single-crystal blade according to claim 6, characterized in that, There are multiple transverse runners (5), and each transverse runner (5) is connected to one of the blade wax molds (1).

8. A method for casting crowned single-crystal blades, characterized in that, Includes the following steps: Step 1: Prepare and assemble the wax model assembly: After assembly, the wax model assembly is a crowned single-crystal blade casting wax model as described in claim 7; Step 2, Shell Making: The wax mold assembly is subjected to investment casting to form a ceramic shell; Step 3: Dewaxing: The ceramic shell is heated to remove the wax mold, resulting in a ceramic shell with a cavity; Step 4, Casting: Preheat the ceramic mold shell with cavity and assemble it onto the cooling copper plate. After assembly, pour in molten metal and obtain the casting by crystal pulling through directional solidification process. Step 5, Cleaning: After the casting cools, remove the ceramic shell to obtain the casting containing the gating system, risers, and blades; Step 6: Cutting: Cut the blade casting from the gating system and remove the top riser structure to obtain a crowned single-crystal blade.

9. The method for casting a crowned single-crystal blade according to claim 8, characterized in that, In step four, the upper surface of the cooling copper plate is provided with a protrusion with the same shape as the support part. When the mold shell is assembled onto the cooling copper plate, the protrusion extends into the inner cavity of the mold shell and fits against the mold shell.

10. A method for casting a crowned single-crystal blade according to claim 9, characterized in that, In step two, the investment casting shell-making process includes multiple dip coatings with refractory slurry, sprinkling with refractory sand, and drying and hardening.

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