Hollow turbine blade directional solidification device with cooperation of local heating and partition cooling

Abstract

The invention relates to the technical field of hollow turbine blade casting, in particular to a hollow turbine blade directional solidification device with synergy of local heating and partitioned cooling, which is characterized in that an electromagnetic auxiliary heating assembly is arranged below a heat insulation plate and can perform local or point-shaped heating or heat preservation on the outer wall of a mold shell; the multi-stage partition cooling assembly is arranged in the cooling cavity, the structure of the mold shell is arranged in a partition mode, the directional solidification effect is achieved, the defects of looseness, freckles and the like are overcome, and the product percent of pass is increased.

Description

Technical Field

[0001] This invention relates to the field of hollow turbine blade casting technology, and more specifically to a directional solidification device for hollow turbine blades that combines local heating and zoned cooling. Background Technology

[0002] Hollow single-crystal turbine blades are core hot-end components of aero-engines, and their internal quality directly determines the engine's performance and lifespan. During the blade casting process, directional solidification methods are used to obtain unidirectionally grown columnar crystals or even single crystals, essentially eliminating transverse grain boundaries perpendicular to the principal stress axis and reducing defects such as segregation, porosity, and the presence of grain boundary carbides. Compared to castings obtained through conventional casting methods, the high-temperature strength, creep resistance, endurance, and thermal fatigue performance of the blades are significantly improved, resulting in a marked improvement in impact toughness and hot strength, and a substantial enhancement of the blades' unidirectional mechanical properties.

[0003] However, the current mainstream directional solidification / single crystal solidification technology has the following drawbacks: 1) A single cooling mechanism cannot cope with the differentiated heat dissipation requirements brought about by the complex wall thickness structure of the blade, resulting in microporousness in the thick parts of the blade and thermal cracking in the thin-walled parts; 2) The temperature gradient and cooling rate during the solidification process cannot be precisely controlled in real time, and the generation of defects such as impurities and freckles is random; thus, the product qualification rate is low and the production cost is increased.

[0004] Therefore, this application is submitted. Summary of the Invention

[0005] The purpose of this invention is to provide a directional solidification device for hollow turbine blades that combines local heating and zoned cooling. By locally heating the outer wall of the mold shell and zoned cooling, the heating process maintains the axial heat dominance inside the mold shell to avoid impurities, and achieves differentiated cooling between the thick and thin parts of the blade during solidification, thus solving the problems existing in the prior art.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following solution: A directional solidification device for hollow turbine blades that combines localized heating and zoned cooling is characterized by comprising a furnace body, within which are provided a heating zone, a cooling zone, and a heat insulation plate located between the heating zone and the cooling zone. Below the heat insulation plate is an electromagnetic auxiliary heating component that maintains a preset distance from the outer wall of the mold shell. The electromagnetic auxiliary heating component provides localized or point-like heating to the outer wall of the mold shell during its lifting and lowering process. Below the heat insulation plate is an independently temperature-controlled multi-stage zoned cooling component. Multiple temperature sensors are pre-embedded in the outer wall of the mold shell, and the multi-stage zoned cooling component adjusts the cooling temperature based on the real-time temperature values ​​of the outer wall of the mold shell monitored by the temperature sensors.

[0007] Furthermore, the electromagnetic auxiliary heating assembly includes an annular plate fixed to the inner wall of the furnace body. The inner wall of the annular plate has a plurality of hydraulic rods arranged in a ring and a high-frequency heating coil located at the extension end of the hydraulic rods. The horizontal extension and retraction of the hydraulic rods maintains a preset distance between the high-frequency heating coil and the outer wall of the mold shell for auxiliary heating.

[0008] Furthermore, the telescopic end of the hydraulic rod is provided with an L-shaped rod, and the end of the L-shaped rod away from the hydraulic rod is provided with a position sensor for monitoring the outer wall of the mold shell. The hydraulic rod telescopically moves according to the monitoring position of the position sensor to maintain a preset distance between the high-frequency heating coil and the outside of the mold shell.

[0009] Furthermore, the multi-level partitioned cooling assembly is located in the cooling jacket below the heat insulation plate. Inside the cooling jacket, there are horizontally arranged fan-shaped cooling plates that perform segmented cooling along the vertical axis. Each layer of fan-shaped cooling plates is arranged in a ring on the inner wall of the cooling jacket, and the arc surface of the fan-shaped ring cooling plate faces the outer wall of the mold shell.

[0010] Furthermore, the cooling temperature of the fan-shaped cooling plate decreases gradually from top to bottom, and it has vertically serpentine cooling channels inside, which are filled with coolant.

[0011] Furthermore, the liquid inlet at the bottom of the cooling channel is connected to the liquid inlet of the coolant via a branch pipe and an annular pipe to form a liquid inlet pipeline; The outlet at the top of the cooling pipe is connected to the coolant recovery port via branch pipe two and ring pipe two, forming a recovery pipeline.

[0012] Furthermore, the first branch pipe is equipped with a heat exchanger for adjusting the cooling temperature, and the first branch pipe and the second branch pipe respectively pass through the connecting block located between the water cooling jacket and the fan-shaped cooling plate.

[0013] Furthermore, ceramic fiber plates for heat insulation are placed between adjacent fan-shaped cooling plates in each layer.

[0014] Furthermore, the mold shell is configured from the inside out as a surface layer, a functional layer, and a back layer. The surface layer directly forms the outer cavity of the hollow turbine blade casting. The functional layer is divided into zones according to the thermal management requirements of the corresponding blade part, including a heat-conducting zone for the thick part of the blade, a heat-insulating zone for the thin-walled part of the blade, and a transition zone between the two. A temperature sensor for real-time monitoring of the mold shell temperature is embedded on the outside of the functional layer.

[0015] Furthermore, the dry basis raw material components of each layer, by weight percentage, are as follows: The surface layer consists of 100 wt% alumina; The thermally conductive zone consists of 55%~70 wt% alumina, with the balance being boron nitride; The transition zone consists of 60%–80 wt% alumina, with the balance being boron nitride; The insulation zone consists of 50%~70 wt% alumina, with the balance being polymethyl methacrylate microspheres; The backing layer consists of 100 wt% aluminosilicate.

[0016] The beneficial effects of this invention are as follows: Firstly, an electromagnetic auxiliary heating component is installed below the heat insulation plate, which can locally or point-like heat or heat preservation of the outer wall of the mold shell, and compensate for the heating of the outer wall of the mold shell, which can effectively reduce radial heat loss; thereby ensuring that the solidification interface grows strictly vertically from bottom to top, eliminating the driving force for the nucleation of impurity crystals, and reducing the generation of impurity crystal defects.

[0017] Secondly, the multi-level zoned cooling components generate an extremely strong cooling effect at the bottom of the mold shell, making its temperature much lower than the melting point of the alloy, while the melt at the top is still kept at a high temperature by the heater. The huge temperature difference creates an ultra-high axial temperature gradient from the high-temperature zone to the low-temperature zone within the mold shell, which is the physical basis for directional solidification and suppressing defects such as porosity and freckles, and ensures that the solidification process proceeds quickly and smoothly from the bottom to the top.

[0018] Thirdly, by dividing the mold shell structure into sections, the content of high thermal conductivity phase is increased in the mold shell areas corresponding to the thicker parts of the blades, allowing the inner surface layer to maintain good chemical stability and not react with the molten metal; at the same time, the outer area has extremely high thermal conductivity, which can quickly dissipate heat from the hot spots. In the mold shell areas corresponding to the thin-walled parts, the content of polymethyl methacrylate microspheres is increased, slowing down heat dissipation and preventing the molten metal from solidifying prematurely, which could lead to incomplete casting or cold shut. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 For the present invention Figure 1 A magnified schematic diagram of the structure of circle A in the middle; Figure 3 A top view schematic diagram of the assembly structure of the electromagnetic auxiliary heating component inside the furnace body; Figure 4 A top view schematic diagram of the assembly structure of the multi-level zoned cooling components within the furnace body; Figure 5 This is a schematic diagram of the cross-sectional structure of the mold shell.

[0020] Reference numerals: 1-Furnace body, 10-Heating zone, 11-Cooling zone, 12-Insulation plate, 2-Mold shell, 20-Surface layer, 21-Functional layer, 210-Heat conduction zone, 211-Superheated zone, 222-Insulation zone, 22-Back layer, 23-Temperature sensor, 3-Multi-level zoned cooling assembly, 30-Water cooling jacket, 31-Fan-shaped cooling plate, 310-Cooling channel, 32-Connecting block, 33-Annular pipe one, 34-Annular pipe two, 35-Branch pipe one, 350-Heat exchanger, 36-Branch pipe two, 37-Liquid inlet, 38-Recovery port, 39-Ceramic fiber plate, 4-Electromagnetic auxiliary heating assembly, 40-Annular plate, 41-Hydraulic rod, 42-High frequency heating coil, 43-Position sensor, 44-L-shaped rod, 5-Lifting platform. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0022] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of the invention.

[0023] At the same time, it should be understood that, for ease of description, the dimensions of the various parts shown in the accompanying drawings are not drawn according to actual scale.

[0024] Furthermore, for clarity and brevity, descriptions of well-known structures, functions, and configurations may have been omitted. Those skilled in the art will recognize that various changes and modifications can be made to the examples described herein without departing from the spirit and scope of this disclosure.

[0025] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0026] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0027] Example 1 Embodiment 1 of the present invention is a directional solidification device for hollow turbine blades that combines local heating and zoned cooling. It includes a furnace body 1, a heating zone 10, a cooling zone 11, and a heat insulation plate 12 located between the heating zone 10 and the cooling zone 11. An electromagnetic auxiliary heating component 4 is provided below the heat insulation plate 12, which maintains a preset distance from the outer wall of the mold shell 2. The electromagnetic auxiliary heating component 4 performs local or point heating on the outer wall of the mold shell 2 during the lifting and lowering process of the mold shell 2. A multi-level zoned cooling component 3 with independent temperature control is provided below the heat insulation plate 12. Multiple temperature sensors 23 are pre-embedded in the outer wall of the mold shell 2. The multi-level zoned cooling component 3 adjusts the cooling temperature according to the temperature value of the outer wall of the mold shell 2 monitored in real time by the temperature sensors 23.

[0028] Reference Figure 1 The furnace body 1 of the directional solidification apparatus of the present invention is divided into a heating zone 10 and a cooling zone 11 from top to bottom. A heat insulation plate 12 is provided between the two to block the heat of the heating zone 10. The mold shell 2 is lifted into the heating zone 10 by a lifting platform 5 and heated to a temperature much higher than the melting point of the alloy (e.g., above 1500°C) for final preheating to ensure uniform temperature of the shell and core and to avoid excessive cooling when the molten metal is injected. The molten ultra-high temperature nickel-based superalloy liquid with precisely controlled composition is poured into the preheated ceramic mold shell 2. At this time, the molten metal fills the cavity and gating system inside the mold shell 2.

[0029] After casting, the mold shell 2 and the cast molten metal are lowered into the cooling chamber by the lifting platform 5. During the descent, the electromagnetic auxiliary heating component 4 located below the heat insulation plate 12 provides localized or point-like heating or heat preservation to the outer wall of the mold shell 2, thus compensating for the radial heat loss. This ensures that the solidification interface grows strictly vertically from bottom to top, eliminating the driving force for impurity crystal nucleation and reducing the generation of impurity crystal defects. Furthermore, when the temperature at a certain location is detected by the temperature sensor 23 embedded in the outer wall of the mold shell 2 and falls below a preset value, the corresponding electromagnetic auxiliary heating component 4 will be activated to provide point-to-point heating to compensate for the heat loss at that location.

[0030] As the mold shell 2 and its internal molten metal descend to the cooling zone 11, the multi-stage zoned cooling assembly 3 generates an extremely strong cooling effect at the bottom of the mold shell 2, keeping its temperature far below the alloy's melting point. Meanwhile, the melt at the top remains at a high temperature thanks to the heater. This significant temperature difference establishes an ultra-high axial temperature gradient within the mold shell 2, pointing from the high-temperature zone to the low-temperature zone. This provides the physical basis for directional solidification and the suppression of defects such as porosity and freckles, ensuring a rapid and stable solidification process from bottom to top. Furthermore, based on the temperature sensor 23 on the outer wall of the mold shell 2, the area at the bottom of the mold shell 2 corresponding to the thicker parts of the blades is subjected to intense cooling to accelerate heat dissipation; while cooling is reduced for thin-walled areas to prevent excessive cooling, achieving localized differentiated cooling and reducing casting defects during directional solidification.

[0031] It should be noted that the temperature monitoring of temperature sensor 23, the temperature control of electromagnetic auxiliary heating component 4, and the cooling temperature control of multi-level zoned cooling component 3 are all implemented by external controllers, which are existing technologies and will not be described in detail here.

[0032] In some preferred embodiments, the electromagnetic auxiliary heating assembly 4 includes an annular plate 40 fixedly connected to the inner wall of the furnace body 1. The inner wall of the annular plate 40 is arranged with a plurality of hydraulic rods 41 and a high-frequency heating coil 42 located at the telescopic end of the hydraulic rods 41. The horizontal telescopic movement of the hydraulic rods 41 allows the high-frequency heating coil 42 to maintain a preset distance from the outer wall of the mold shell 2 for auxiliary heating.

[0033] Reference Figure 3 Multiple hydraulic rods 41 are installed on the inner wall of the annular plate 40. The telescopic ends of the hydraulic rods 41 are equipped with L-shaped rods 44. A position sensor 43 is installed at the end of the L-shaped rod 44 furthest from the hydraulic rod 41 to monitor the outer wall of the mold shell 2. The hydraulic rods 41 extend and retract according to the position monitored by the position sensor 43, maintaining a preset distance between the high-frequency heating coil 42 and the outside of the mold shell 2. The number of position sensors 43 is consistent with the number of high-frequency heating coils 42. They are used to monitor whether the distance between the outer wall of the mold shell 2 and the position sensor 43 is within the preset distance. If it is not within the preset distance, the hydraulic rods 41 will move up and down, driving the high-frequency heating coil 42 to move within the preset distance. The specific temperature value of the high-frequency heating coil 42 is then adaptively adjusted according to the temperature monitored by the temperature sensor 23 to ensure point-to-point heating. The center of the position sensor 43 coincides with the center of the high-frequency heating coil 42. Heat insulation is applied to the hydraulic rods 41, L-shaped rods 44, and position sensors 43; this is a standard technical operation and will not be described in detail here.

[0034] Example 2 Embodiment 2 of the present invention is implemented based on Embodiment 1. The multi-level partitioned cooling component 3 is located in the cooling sleeve below the heat insulation plate 12. Inside the cooling sleeve, there are horizontally arranged fan-shaped cooling plates 31 that perform segmented cooling along the vertical axis. Each fan-shaped cooling plate 31 is arranged in a ring on the inner wall of the cooling sleeve, and the arc surface of the fan-shaped ring cooling plate faces the outer wall of the mold shell 2.

[0035] Reference Figure 1 , Figure 2 and Figure 4The multi-level partitioned cooling component 3 performs segmented cooling along the vertical axis, with the top fan-shaped cooling plate 31 being the strong cooling zone, the middle layer being the medium cooling zone, and the bottom layer being the weak cooling zone. This creates a huge temperature difference between the melt at the top and the bottom of the mold shell 2, establishing an ultra-high axial temperature gradient from the high-temperature zone to the low-temperature zone within the mold shell 2. This enables directional solidification and suppresses defects such as porosity and freckles, ensuring that the solidification process proceeds quickly and smoothly from the bottom to the top. At the same time, the specific cooling temperature of each fan-shaped cooling plate 31 can be adjusted according to the temperature monitoring of the mold shell 2, and the cooling effect can be strengthened or reduced according to the thickness of the blade and the thin-walled part.

[0036] Furthermore, the cooling temperature of the fan-shaped cooling plate 31 decreases progressively from top to bottom, and it has vertically arranged serpentine cooling channels 310 inside, which are filled with coolant. This progressive arrangement includes a first stage, a second stage, and several stages, with the horizontal length of the fan-shaped cooling plate 31 gradually shortening in each stage. The first stage's fan-shaped cooling plate 31 is closer to the center of the mold shell 2, and this process continues step by step. In each stage, at least one layer of fan-shaped cooling plates 31 of the same specifications is horizontally arranged in a ring inside the water-cooling ring and fixed in place. For example... Figure 2 The same specification fan-shaped cooling plate 31 has two layers. In actual application, the same specification fan-shaped cooling plate 31 can be set according to the specific situation, which will not be elaborated here.

[0037] In some preferred embodiments, the liquid inlet 37 at the bottom of the cooling channel 310 is connected to the liquid inlet 37 of the coolant via a branch pipe 35 and an annular pipe 33 to form a liquid inlet pipe. The outlet at the top of the cooling channel 310 is connected to the coolant recovery port 38 via branch pipe 36 and annular pipe 34, forming a recovery pipeline. The cooling channel 310 is arranged in a vertical serpentine pattern, which allows it to evenly cover the entire fan-shaped cooling plate 31, ensuring that the coolant fills the cooling channel 310. The fan-shaped cooling plate 31 can be made of metal, with the cooling plate body and the cooling channel 310 located inside it formed by milling. The cooling channel 310 ensures sufficient heat exchange between the coolant and the metal wall of the fan-shaped cooling plate 31; at the same time, the vertical serpentine arrangement can greatly disturb the flow of the coolant, break the laminar boundary layer, enhance heat transfer, and improve cooling efficiency.

[0038] In addition, inlets and outlets are respectively provided at the top and bottom of the cooling channel 310, connecting the inlet pipe and the return pipe respectively, so as to replace the coolant in the cooling channel 310 in a timely manner. At the same time, each branch pipe 1 35 and branch pipe 2 36 is equipped with a valve to independently control the inlet and return of coolant in each fan-shaped cooling plate 31. This is existing technology and will not be described in detail here.

[0039] Meanwhile, the branch pipe 35 is equipped with a heat exchanger 350 for adjusting the cooling temperature. Branch pipe 35 and branch pipe 36 respectively pass through the connecting block 32 located between the water-cooled jacket 30 and the fan-shaped cooling plate 31. The heat exchanger 350 can be controlled by an external controller. Based on the temperature monitored by the temperature sensor 23 in the outer wall of the mold shell 2, the heat exchanger 350 can be started by the external controller. This is a prior art technique, ensuring that the cooling temperature of the corresponding area meets the temperature of the outer wall of the mold shell 2, thereby enhancing the cooling effect.

[0040] Specifically, a ceramic fiber plate 39 for heat insulation is provided between adjacent fan-shaped cooling plates 31 in each layer. The ceramic fiber plate 39 has extremely low thermal conductivity, which isolates the heat transfer between adjacent fan-shaped cooling plates 31 in the horizontal direction, allowing each fan-shaped cooling plate 31 to adjust the cooling intensity individually. The cooling flow rate can be increased in one area and decreased in another area, realizing zoned control and differentiated cooling.

[0041] Example 3 The preparation process of the mold shell 2 in this embodiment is as follows: first, the slurry is prepared, and then it is realized through 3D printing technology, degreasing, sintering and post-processing.

[0042] The final mold shell 2 is configured from the inside out as a surface layer 20, a functional layer 21, and a back layer 22. The surface layer 20 directly forms the outer cavity of the hollow turbine blade casting. The functional layer 21 is divided into sections according to the thermal management requirements of the corresponding blade part, including a heat-conducting area 210 corresponding to the thick part of the blade, a heat-insulating area 222 corresponding to the thin-walled part of the blade, and a transition area between the two. A temperature sensor 23 for real-time monitoring of the temperature of the mold shell 2 is embedded on the outside of the functional layer 21.

[0043] Reference Figure 5 By dividing the mold shell 2 into sections, the surface layer 20 becomes the inner surface of the mold shell 2, providing chemical stability to the entire mold shell 2 and ensuring that it does not react with the high-temperature alloy liquid, thus guaranteeing the surface quality of the blades. The functional layer 21 is divided into a heat-conducting zone 210, a transition zone, and a heat-insulating zone 222. The heat-conducting zone 210 corresponds to the thicker parts of the blade, providing high thermal conductivity to quickly remove heat from the thicker parts and suppress porosity. The transition zone can mitigate thermal stress between the heat-conducting zone 210 and the heat-insulating zone 222, preventing interlayer delamination. The heat-insulating zone 222 insulates the thin-walled parts of the blade, preventing overcooling and thermal cracking. The back layer 22 is located on the outermost layer of the mold shell 2, i.e., the outer wall part, mainly providing mechanical strength and overall structural support, ensuring that the mold shell 2 has sufficient strength during handling, firing, and casting, and will not crack or deform. The sectioned mold shell 2 can achieve synchronous solidification of all blades, allowing all blades to complete directional solidification at the same time, avoiding the obstruction of subsequent feeding by blades that solidify first.

[0044] Specifically, by weight percentage, the dry basis raw material components of each layer are as follows: The surface layer 20 includes 100wt% alumina, which must be of high purity to ensure that it does not react with the high-temperature alloy liquid; The thermally conductive zone 210 comprises 55%~70 wt% alumina, with the balance being boron nitride. The use of boron nitride can improve chemical stability. The transition zone consists of 60%~80 wt% alumina, with the balance being boron nitride, wherein the proportion of boron nitride changes gradually from the inside to the outside. The heat insulation zone 222 comprises 50%~70 wt% alumina, with the balance being polymethyl methacrylate microspheres; The backing layer 22 comprises 100 wt% aluminosilicate, using inexpensive refractory materials, and primarily provides structural support.

[0045] For each section of the functional layer 21 in the mold shell 2, the extrusion ratio of different slurries is adjusted in real time through the multi-channel system of the 3D printing equipment. For example, when the print head is printing the thick part of the blade, it will extrude a slurry with a high boron nitride content; while when it moves to the thin-walled part of the blade, it will automatically switch to a slurry with a high porosity content.

[0046] By partitioning the structure of mold shell 2, the content of a high thermal conductivity phase is increased in the mold shell 2 region corresponding to the thicker parts of the blade, allowing the inner surface layer 20 to maintain good chemical stability and not react with the molten metal; at the same time, the outer region has extremely high thermal conductivity, which can quickly dissipate heat from the hot spot. In the mold shell 2 region corresponding to the thin-walled parts, the content of polymethyl methacrylate microspheres is increased, slowing down heat dissipation and preventing the molten metal from solidifying prematurely, which could lead to incomplete casting or cold shut.

[0047] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A directional solidification device for hollow turbine blades that combines localized heating and zoned cooling, characterized in that, The furnace body (1) includes a heating zone (10), a cooling zone (11), and a heat insulation plate (12) located between the heating zone (10) and the cooling zone (11). An electromagnetic auxiliary heating component (4) with a preset distance from the outer wall of the mold shell (2) is provided below the heat insulation plate (12). The electromagnetic auxiliary heating component (4) heats the outer wall of the mold shell (2) locally or in a point manner during the lifting and lowering of the mold shell (2). A multi-level partitioned cooling component (3) with independent temperature control is provided below the heat insulation plate (12). Multiple temperature sensors (23) are embedded in the outer wall of the mold shell (2). The multi-level partitioned cooling component (3) adjusts the cooling temperature according to the temperature value of the outer wall of the mold shell (2) monitored in real time by the temperature sensors (23).

2. The hollow turbine blade directional solidification device with coordinated local heating and zoned cooling according to claim 1, characterized in that, The electromagnetic auxiliary heating assembly (4) includes an annular plate (40) fixed to the inner wall of the furnace body (1). The inner wall of the annular plate (40) is arranged with multiple hydraulic rods (41) and a high-frequency heating coil (42) located at the extension end of the hydraulic rods (41). The horizontal extension and retraction of the hydraulic rods (41) allows the high-frequency heating coil (42) to maintain a preset distance from the outer wall of the mold shell (2) for auxiliary heating.

3. The hollow turbine blade directional solidification device with coordinated local heating and zoned cooling according to claim 2, characterized in that, The telescopic end of the hydraulic rod (41) is provided with an L-shaped rod (44). The end of the L-shaped rod (44) away from the hydraulic rod (41) is provided with a position sensor (43) for monitoring the outer wall of the mold shell (2). The hydraulic rod (41) telescopically moves according to the monitoring position of the position sensor (43) so that the high-frequency heating coil (42) and the outside of the mold shell (2) maintain a preset distance.

4. The hollow turbine blade directional solidification device with coordinated local heating and zoned cooling according to claim 2, characterized in that, The multi-level partitioned cooling assembly (3) is located in the cooling sleeve below the heat insulation plate (12). Inside the cooling sleeve, there are horizontally arranged fan-shaped cooling plates (31) that are segmented and cooled along the vertical axis. Each fan-shaped cooling plate (31) is arranged in a ring on the inner wall of the cooling sleeve, and the arc surface of the fan-shaped ring cooling plate faces the outer wall of the mold shell (2).

5. The hollow turbine blade directional solidification device with coordinated local heating and zoned cooling according to claim 4, characterized in that, The cooling temperature of the fan-shaped cooling plate (31) decreases gradually from top to bottom, and its interior is provided with vertically arranged serpentine cooling channels (310), which are filled with coolant.

6. The hollow turbine blade directional solidification device with coordinated local heating and zoned cooling according to claim 5, characterized in that, The liquid inlet (37) at the bottom of the cooling channel (310) is connected to the liquid inlet (37) of the coolant via a branch pipe (35) and an annular pipe (33) to form a liquid inlet pipe. The outlet at the top of the cooling pipe is connected to the coolant recovery port (38) via branch pipe two (36) and ring pipe two (34) to form a recovery pipe.

7. The hollow turbine blade directional solidification device with coordinated local heating and zoned cooling according to claim 6, characterized in that, The first branch pipe (35) is equipped with a heat exchanger (350) for adjusting the cooling temperature. The first branch pipe (35) and the second branch pipe (36) pass through the connecting block (32) located between the water cooling jacket (30) and the fan-shaped cooling plate (31), respectively.

8. The hollow turbine blade directional solidification device with coordinated local heating and zoned cooling according to claim 6, characterized in that, Ceramic fiberboard (39) for heat insulation is provided between adjacent fan-shaped cooling plates (31) on each layer.

9. The directional solidification device for hollow turbine blades that combines local heating and zoned cooling according to claim 7, characterized in that, The mold shell (2) is configured from the inside out as a surface layer (20), a functional layer (21) and a back layer (22), wherein the surface layer (20) directly constitutes the outer cavity of the hollow turbine blade casting; The functional layer (21) is divided into zones according to the thermal management requirements of the corresponding blade parts, including the heat conduction zone (210) corresponding to the thick part of the blade, the heat insulation zone (222) corresponding to the thin wall part of the blade, and the transition zone between the two; the temperature sensor (23) for real-time monitoring of the temperature of the mold shell (2) is embedded in the outside of the functional layer (21).

10. The directional solidification device for hollow turbine blades combining local heating and zoned cooling according to claim 9, characterized in that, By weight percentage, the dry basis raw material components of each layer are as follows: The surface layer (20) comprises 100 wt% alumina; The thermally conductive zone (210) comprises 55%~70 wt% alumina, with the balance being boron nitride; The transition zone consists of 60%–80 wt% alumina, with the balance being boron nitride; The heat insulation zone (222) consists of 50%~70 wt% alumina, with the balance being polymethyl methacrylate microspheres; The backing layer (22) comprises 100 wt% aluminosilicate.

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