Process for the production of a turbine blade based on a dot matrix topology of photocured ceramic cores

Abstract

The application relates to a preparation process of a lattice topology turbine blade based on a light-cured ceramic core, which comprises the following steps: parameterized modeling of the lattice topology is carried out to improve the cooling efficiency of the turbine blade, a three-dimensional digital model of the lattice topology which is symbiotic with the shape of the inner cavity of the turbine blade is generated, and an initial design model of the turbine blade is obtained; simulation and checking are carried out to obtain an optimized model of the turbine blade, reverse structure design is carried out to obtain a ceramic core model; a ceramic core test piece is prepared by adopting a light-cured 3D printing technology, and a turbine blade test piece with the lattice topology is further prepared; the turbine blade test piece is detected, the digital model of the lattice topology is optimized and finalized according to the detection data, and a final model of the turbine blade is obtained; and the turbine blade with the lattice topology is prepared based on the final model. Through the lattice topology optimization design and forming process innovation, the turbine blade cooling efficiency is improved.

Description

Technical Field

[0001] This invention relates to a photopolymer additive manufacturing technology and a precision casting technology, and in particular to a process for preparing turbine blades with a lattice topology structure based on a photopolymer ceramic core. Background Technology

[0002] With the increasing demand for energy and power from modern industry, improving the performance of gas turbines and aero engines has become an important research direction. As a key component of engines, the performance of single-crystal turbine blades directly affects the efficiency and reliability of the engine. Therefore, it is urgent to improve the cooling efficiency of single-crystal turbine blades to enable them to operate stably under high temperature and high pressure environments.

[0003] In existing cooling technologies, the internal cooling structure of turbine blades has evolved from traditional structures such as serpentine channels, turbulence columns, and film cooling holes to complex layered cooling structures, and from single-layer walls to double-layer walls. The complex internal cavity cooling structure of turbine blades relies on the structural design of ceramic cores.

[0004] In conventional technologies, ceramic cores are manufactured through hot press molding and die forming. Limited by traditional forming processes, the highest-efficiency blade cavity currently available has a double-walled cooling structure with a cooling efficiency of 0.6-0.7, reaching its ceiling. Traditional forming processes struggle to manufacture ceramic cores with complex internal three-dimensional interconnected channels (especially lattice topologies), limiting innovation in cooling structures and failing to meet next-generation design requirements.

[0005] Photopolymer additive manufacturing of ceramic cores is a novel, high-precision forming technology that overcomes the technical bottlenecks of traditional processes for fabricating complex internal cavity structures. The forming process requires no tooling or molds; the 3D digital model directly drives the printing process, allowing for rapid design iteration and making it suitable for small-batch, customized production. Photopolymer additive manufacturing of ceramic cores can create arbitrarily complex 3D structures, including internally closed holes, suspended structures, freeform surfaces (such as Gyroids), and lattice topologies.

[0006] Compared to traditional hot-pressing processes, photopolymerization additive manufacturing technology has turned the innovative design of the "lattice topology" of ceramic cores from concept to reality, thereby improving the cooling efficiency of single-crystal turbine blades and enhancing the technological level of next-generation aero-engines.

[0007] Currently, domestic and international research mainly focuses on the preparation of ceramic materials with simple lattice structures. There are no reports on the preparation of ceramic cores with lattice topology structures using photopolymerization additive manufacturing technology. Existing technologies cannot efficiently prepare turbine blades with lattice topology cooling structures, thus limiting the further improvement of turbine blade cooling efficiency. Summary of the Invention

[0008] In view of this, the present invention provides a process for fabricating turbine blades with a lattice topology structure based on a photocurable ceramic core, the main purpose of which is to improve the cooling efficiency of turbine blades.

[0009] To achieve the above objectives, the present invention mainly provides the following technical solutions:

[0010] On one hand, embodiments of the present invention provide a fabrication process for a lattice topology turbine blade based on a photocurable ceramic core, comprising the following steps:

[0011] Step 1): With the goal of improving the cooling efficiency of turbine blades, parametric modeling and computational fluid dynamics optimization of the lattice topology are performed to generate a digital model of the three-dimensional lattice topology that is symbiotic with the internal cavity shape of the turbine blade, and to obtain the initial design model of the turbine blade with the lattice topology.

[0012] Step 2): Simulate and verify the initial design model of the turbine blade to obtain an optimized turbine blade model that meets the preset cooling performance and structural strength thresholds;

[0013] Step 3): Based on the turbine blade optimization model, reverse structure design is performed to obtain a ceramic core model; based on the ceramic core model, a ceramic core specimen with a lattice topology is prepared using photopolymerization 3D printing technology.

[0014] Step 4): Based on the ceramic core specimen with lattice topology, a turbine blade specimen with lattice topology is prepared;

[0015] Step 5): The turbine blade specimen with the lattice topology is tested, and the test data is compared with the simulation results in Step 2). Based on the comparison results, the digital model of the three-dimensional lattice topology structure that is symbiotic with the inner cavity shape of the turbine blade is finally optimized and finalized to obtain the final model of the turbine blade.

[0016] Step 6): Based on the final model of the turbine blade, reverse structure design is performed to obtain an optimized ceramic core model; based on the optimized ceramic core model, a ceramic core is fabricated using photopolymerization 3D printing technology; based on the ceramic core, a turbine blade with a lattice topology structure is fabricated.

[0017] Preferably, in step 1):

[0018] When performing parametric modeling of the lattice topology, dense lattice elements are used for a defined region of the turbine blade, and the element angles and rod diameters are optimized. Preferably, the defined region includes one or more parts of the turbine blade's leading edge, blade body, tip, and trailing edge. Preferably, the dense lattice elements include any one or more of Gyroid surfaces, octahedrons, and truss lattice structures. And / or

[0019] Rapid parametric modeling of lattice topology structures is achieved through a two-stage control approach: first selecting the topology, then adjusting the parameters. This allows for the acquisition of geometric variants with different relative densities and mechanical and thermal properties under the same lattice topology. The influence on pore flow velocity is then analyzed by calculating lattice flow heat transfer performance. The heat transfer coefficient ratio is linked to the pump power ratio using Reynolds analogy, allowing for the calculation of heat transfer effects and flow resistance for different lattice topologies, thereby achieving computational fluid dynamics optimization. Preferably, the two-stage control approach involves: selecting optimal lattice topology units according to an efficient cooling model, and then optimizing the heat transfer effect and flow resistance of the lattice topology by adjusting the rod diameter and unit angle, thus completing the fluid dynamics optimization.

[0020] Preferably, step 2) includes:

[0021] Step 21): Based on the initial design model of the turbine blade, construct a parametric lattice topology 3D model library;

[0022] Step 22): Based on the parameterized lattice topology 3D model library, perform coupled fluid dynamics and structural mechanics simulation to obtain simulation data; preferably, the simulation data includes flow field distribution data, heat transfer coefficient data and structural stress field data;

[0023] Step 23): Based on the simulation data, with the optimization objectives of maximizing cooling efficiency and minimizing maximum flow resistance, perform multiple rounds of iterative optimization on the unit configuration, rod diameter and angle of the lattice topology in the initial design model of the turbine blade to obtain a turbine blade optimization model that meets the preset cooling performance and structural strength thresholds.

[0024] Preferably, in step 21): the porosity of the lattice structure is controlled, different types of truss lattices are defined as cooling structures to construct a dataset, two nodes, four nodes, and six nodes are added in the cubic unit cell to generate the required truss lattice structure, and multiple configuration combinations are achieved by controlling the number of rods and the lattice topology, and a three-dimensional model database of the lattice topology is systematically constructed.

[0025] Preferably, in step 22), fluid dynamics and structural mechanics coupled simulation is performed using Fluent software;

[0026] Preferably, in step 23), the flow resistance refers to the flow resistance to heat flow.

[0027] Preferably, in step 23), the preset cooling performance includes: comprehensive cooling efficiency ≥ 0.8; the structural strength threshold includes: tensile strength ≥ 0.8; more preferably, the comprehensive cooling efficiency refers to the dimensionless temperature calculation of the surface of the metal substrate (e.g., turbine blade substrate), and the calculation formula is as follows:

[0028] ;

[0029] Among them, T g Mainstream gas temperature; T m T represents the actual surface temperature of the cooled metal wall (e.g., turbine blade substrate). c,in Coolant inlet temperature;

[0030] Preferably, in step 3):

[0031] Based on the turbine blade optimization model, a 3D modeling software is used for inverse structural design to create a 3D model of the ceramic core; and / or

[0032] The lattice units of the lattice topology structure on the ceramic core model are tetrahedral or octahedral, with an included angle of 30-60° and a rod diameter of 0.5-1mm.

[0033] Preferably, in step 3):

[0034] The ceramic core model is imported into a photopolymer additive manufacturing system, and the ceramic core slurry is subjected to photopolymer 3D printing to obtain a green blank. The green blank is then degreased and sintered to obtain a ceramic core specimen with a lattice topology.

[0035] Preferably, in step 3),

[0036] By volume fraction, the ceramic core slurry comprises 35%-45% liquid solvent and 55%-65% solid powder; wherein the liquid solvent comprises: 79-90 parts by volume of photosensitive resin, 5-20 parts by volume of photoinitiator, and 5-10 parts by volume of dispersant; wherein the solid powder comprises: 70-90 parts by weight of skeleton powder and 10-30 parts by weight of mineralizer.

[0037] Preferably, the particle size of the skeleton powder is 20-85 μm;

[0038] Preferably, the particle size of the mineralizer is 0.1-5 μm;

[0039] Preferably, the photosensitive resin is one or more of trimethylolpropane triacrylate, trimethylpropane triacrylate, tripropylene glycol diacrylate, and 1,6-hexanediol diacrylate.

[0040] Preferably, the photoinitiator is one or more of 2-hydroxy-2-methyl-1-phenylacetone-1, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide;

[0041] Preferably, the dispersant is one or more of sodium hexametaphosphate, sodium polyacrylate, ammonium polyacrylate, and polyvinylpyrrolidone;

[0042] Preferably, the skeleton powder is silicon dioxide and / or molten glass powder;

[0043] Preferably, the mineralizing agent is silicon dioxide and / or chromium silicate.

[0044] Preferably, in step 3):

[0045] The process parameters for the photopolymerization printing process are as follows: printing layer thickness is 50-200μm, and laser power is 3-45mW / cm². 2 The scanning speed is 800-2000 mm / s; and / or

[0046] The degreasing process includes: heating the raw blank from room temperature to 230-350°C at a heating rate of 1-2°C / min in an air atmosphere, and holding it at 230-350°C for 240-360 min; then heating it to 450-630°C at a heating rate of 0.5-1.5°C / min, and holding it at 450-630°C for 360-720 min; then cooling it back to room temperature at a cooling rate of 1-3°C / min; and / or

[0047] The sintering process includes: in a protective atmosphere with a gas pressure of 0.1-0.3 MPa, heating the degreased green blank from room temperature to 1000-1100℃ at a heating rate of 3-8℃ / min, and holding it at 1000-1100℃ for 360-720 min; then heating it to 1150-1300℃ at a heating rate of 1-2℃ / min, and holding it at 1150-1300℃ for 240-480 min; then cooling it to 450-500℃ at a cooling rate of 2-5℃ / min, and after furnace cooling, obtaining a ceramic core specimen with a lattice topology.

[0048] Preferably, in step 4):

[0049] The ceramic core specimen with lattice topology is pressed into a wax pattern to prepare a shell; the shell is then cast; the cast part is then deshelled and decored to obtain a turbine blade casting; the turbine blade casting is then heat-treated and polished to obtain a turbine blade specimen with lattice topology.

[0050] Preferably, the turbine blade specimen with a lattice topology is a single-crystal turbine blade.

[0051] Preferably, in step 5):

[0052] The tests performed on the turbine blade specimen with the lattice topology include cooling effect testing, tensile strength testing, and relative density testing.

[0053] Preferably, in step 5):

[0054] Based on the comparison results, the digital model of the three-dimensional lattice topology is finally optimized and finalized.

[0055] Preferably, based on the performance test data of the turbine blade specimen, the lattice topology with the best performance is selected for model finalization;

[0056] Preferably, the performance test data includes cold effect test data, tensile strength test data, and relative density test data.

[0057] Compared with the prior art, the fabrication process of the turbine blade based on the lattice topology structure of the photocurable ceramic core of the present invention has at least the following beneficial effects:

[0058] This invention provides a fabrication process for a turbine blade with a lattice topology structure based on a photopolymerized ceramic core, comprising the following steps: Step 1): To improve the cooling efficiency of the turbine blade, parametric modeling and computational fluid dynamics optimization of the lattice topology structure are performed to generate a digital model of a three-dimensional lattice topology structure that is symbiotic with the internal cavity shape of the turbine blade, thereby obtaining an initial design model of the turbine blade with the lattice topology structure; Step 2): The initial design model of the turbine blade is simulated and verified to obtain an optimized model of the turbine blade that meets preset cooling performance and structural strength thresholds; Step 3): Based on the optimized model of the turbine blade, inverse structural design is performed to obtain a ceramic core model; Based on the ceramic core model, a turbine blade with a lattice topology structure is fabricated using photopolymerized 3D printing technology. Step 4): Based on the ceramic core specimen with lattice topology, prepare a turbine blade specimen with lattice topology; Step 5): Test the turbine blade specimen with lattice topology, and compare the test data with the simulation results in Step 2); based on the comparison results, perform final optimization and shaping of the digital model of the three-dimensional lattice topology structure used to coexist with the internal cavity shape of the turbine blade, and obtain the final model of the turbine blade; Step 6): Based on the final model of the turbine blade, perform reverse structure design to obtain the ceramic core optimization model; based on the ceramic core optimization model, use photopolymer 3D printing technology to prepare the ceramic core; based on the ceramic core, prepare the turbine blade with lattice topology. The above scheme is explained as follows: This invention pioneers a new generation of rapid verification and shaping technology route for complex internal cavity turbine blades based on photopolymer additive ceramic cores. This route breaks through the capability and cycle bottlenecks of traditional mold manufacturing, realizing the "design as manufacturing" of high-performance single-crystal blade lattice topology structures. By combining digital model design optimization with photopolymer additive manufacturing processes, the cycle time from conceptual design to qualified casting of the blade's internal cavity has been shortened by orders of magnitude. This not only achieves a leap in blade cooling performance but also establishes an agile development process from digital models to prototypes, laying the foundation for rapid iteration and performance leaps in next-generation high-performance blades. Furthermore, the lattice topology provides a surface area far exceeding that of traditional turbulence columns, significantly enhancing convective heat transfer between the cooling airflow and the blade wall. The complex, three-dimensionally interconnected flow channels effectively disrupt the laminar boundary layer of the cooling air, promoting turbulence and significantly improving the heat transfer coefficient. The lattice structure enables uniform distribution of the cooling medium in three-dimensional space, avoiding localized overheating and effectively reducing the overall temperature gradient and thermal stress of the blade. While ensuring cooling performance, the lattice structure itself is a highly efficient and lightweight structure, contributing to reduced blade weight. In addition, a well-designed lattice structure maintains good structural stiffness and strength, preventing deformation or failure of the blade during casting and service.

[0059] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0060] Figure 1 This is a schematic diagram of the fabrication process of a turbine blade with a lattice topology structure based on a photocurable ceramic core.

[0061] Figure 2 This is a schematic diagram of the fabrication process for photocurable ceramic cores.

[0062] Figure 3 Figure 1 shows the design drawing of the photocurable ceramic core model; Figure 2 shows the design drawing of the photocurable ceramic core model in Example 1; Figure 3 shows the design drawing of the photocurable ceramic core model in Example 2; Figure 4 shows the design drawing of the photocurable ceramic core model in Example 3.

[0063] Figure 4 Figure 1 shows an enlarged view of the unit cells of the lattice topology structure; Figure 2 shows an enlarged view of the unit cells of the lattice topology structure in Example 3; Figure 3 shows an enlarged view of the unit cells of the lattice topology structure in Example 1; Figure 4 shows an enlarged view of the unit cells of the lattice topology structure in Example 2.

[0064] Figure 5 Figure 1 shows a physical image of a ceramic core specimen with a lattice topology structure; Figure 2 shows a physical image of a ceramic core specimen with a lattice topology structure in Example 1; Figure 3 shows a physical image of a ceramic core specimen with a lattice topology structure in Example 2; Figure 4 shows a physical image of a ceramic core specimen with a lattice topology structure in Example 3.

[0065] Figure 6 This is a front view of the turbine blade with a lattice topology in Example 1;

[0066] Figure 7 Figure 1 is a top view of the inner cavity of a turbine blade with a lattice topology structure; Figure 2 is a top view of the inner cavity of a turbine blade with a lattice topology structure in Example 1; Figure 3 is a top view of the inner cavity of a turbine blade with a lattice topology structure in Example 2; Figure 4 is a top view of the inner cavity of a turbine blade with a lattice topology structure prepared in Example 3. Detailed Implementation

[0067] To further illustrate the technical means and effects adopted by the present invention to achieve the intended purpose, the specific embodiments, structures, features, and effects according to the present invention will be described in detail below with reference to the accompanying drawings and preferred embodiments. In the following description, different "embodiments" or "embodiments" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0068] This invention provides a fabrication process for turbine blades with a lattice topology structure based on a photocurable ceramic core. Through optimized design of the lattice topology and innovative forming process, the cooling efficiency of single-crystal blades is improved. The main solutions of this invention are as follows:

[0069] On one hand, embodiments of the present invention provide a fabrication process for turbine blades with a lattice topology structure based on a photocurable ceramic core, such as... Figure 1 and Figure 2 As shown, it includes the following steps:

[0070] Step 1): With the goal of improving the cooling efficiency of turbine blades, parametric modeling and computational fluid dynamics optimization of the lattice topology are performed to generate a digital model of the three-dimensional lattice topology that is symbiotic with the internal cavity shape of the turbine blade, and the initial design model of the turbine blade with the lattice topology is obtained.

[0071] Specifically, in this step, with the goal of improving the cooling efficiency of the turbine blades, parametric modeling and computational fluid dynamics optimization of the lattice topology are performed. For regions with high heat transfer requirements (including one or more parts of the turbine blade's leading edge, blade body, tip, and trailing edge), dense lattice elements with high specific surface area (such as Gyroid surfaces, octahedrons, and truss lattice structures) are used. The element angles and rod diameters are optimized to ultimately generate a three-dimensional lattice topology digital model that conforms to the blade's internal shape and has precise geometric definitions, thus obtaining the initial design model of the turbine blade. Preferably, in regions other than those with high heat transfer requirements, conventional film cooling structures are used to improve cooling efficiency.

[0072] Regarding the "parametric modeling and computational fluid dynamics optimization of lattice topologies," the following explanation is provided: Rapid parametric modeling of lattice topologies is achieved through a two-stage control approach: "topology selection followed by parameter adjustment." This yields geometric variants of the same lattice topology with different relative densities and mechanical-thermal properties. Then, by calculating the lattice flow heat transfer performance, the impact on pore flow velocity is analyzed. Using Reynolds analogy, the heat transfer coefficient ratio is linked to the pump power ratio, and the heat transfer effect and flow resistance of different lattice topologies are calculated, thereby achieving computational fluid dynamics optimization. Preferably, the two-stage control approach of "topology selection followed by parameter adjustment" refers to: selecting optimal lattice topology units according to an efficient cooling model, and then optimizing the heat transfer effect and flow resistance of the lattice topology by adjusting the rod diameter and unit angle, thus completing the fluid dynamics optimization.

[0073] Step 2): Simulate and verify the initial design model of the turbine blade to obtain an optimized turbine blade model that meets preset cooling performance and structural strength thresholds. Step 2): includes:

[0074] Step 21): Based on the initial design model of the turbine blade, construct a parametric lattice topology 3D model library;

[0075] In this step: control the porosity of the lattice structure, define different types of truss lattices as cooling structures to construct a dataset, add two nodes, four nodes, and six nodes in the small cubic unit cell to generate the required truss lattice structure, and achieve multiple configuration combinations by controlling the number of members and the topology, and systematically construct a 3D model database of lattice topology.

[0076] Step 22): Based on the parameterized lattice topology 3D model library, perform coupled fluid dynamics and structural mechanics simulation to obtain simulation data; preferably, the simulation data includes flow field distribution data, heat transfer coefficient data and structural stress field data;

[0077] Specifically, in this step, relevant data is extracted in Fluent software, a typical computational domain model of inlet section—test section—outlet section is set up, and coupled fluid dynamics and structural mechanics simulations are performed. Matlab and Tecplot are used for post-processing of the simulation data. The simulation data includes flow field distribution data, heat transfer coefficient data, and structural stress field data. By comparing the drag, Nusselt number ratio, and comprehensive heat transfer factor at different Reynolds numbers, the lattice topology parameters with good heat transfer effect, acceptable flow resistance, and the best overall heat transfer performance are obtained.

[0078] Step 23): Based on the simulation data, with the optimization objectives of maximizing cooling efficiency and minimizing maximum flow resistance, perform multiple rounds of iterative optimization on the unit configuration, rod diameter and angle of the lattice topology in the initial design model of the turbine blade to obtain a turbine blade optimization model that meets the preset cooling performance and structural strength thresholds.

[0079] This step is performed in Fluent software.

[0080] The preset cooling performance includes: overall cooling efficiency ≥ 0.8; the structural strength threshold includes: tensile strength ≥ 0.8; more preferably, the overall cooling efficiency refers to the dimensionless temperature calculation of the surface of the metal substrate (turbine blade substrate), and the calculation formula is as follows:

[0081] ;

[0082] Among them, T g Mainstream gas temperature; T m T: The actual surface temperature of the cooled metal wall (e.g., blade substrate); c,in Coolant inlet temperature;

[0083] Step 3): Based on the turbine blade optimization model, reverse structure design is performed to obtain a ceramic core model with a lattice topology; based on the ceramic core model with the lattice topology, a ceramic core specimen is prepared using photopolymerization 3D printing technology.

[0084] The "reverse structure design" is explained as follows: A ceramic core is placed inside the blade cavity to form the complex cooling flow channels within the blade. The shape of the ceramic core directly corresponds to the shape of the internal cavity of the blade, and is the opposite of the shape of the external solid structure of the blade. Therefore, the external solid structure of the blade is the positive structure, and the ceramic core is the reverse structure of the blade.

[0085] Among these methods, 3D modeling software is used for reverse structural design to create ceramic core models.

[0086] The lattice units of the lattice topology structure on the ceramic core model are tetrahedral or octahedral, with an included angle of 30-60° and a rod diameter of 0.5-1mm.

[0087] The ceramic core model is imported into a photopolymer additive manufacturing system, and the ceramic core slurry is subjected to photopolymer 3D printing to obtain a green blank; the green blank is then degreased and sintered to obtain a ceramic core specimen.

[0088] By volume fraction, the ceramic core slurry comprises 35%-45% liquid solvent and 55%-65% solid powder; wherein the liquid solvent comprises: 79-90 parts by volume of photosensitive resin, 5-20 parts by volume of photoinitiator, and 5-10 parts by volume of dispersant; wherein the solid powder comprises: 70-90 parts by weight of skeleton powder and 10-30 parts by weight of mineralizer; preferably, the particle size of the skeleton powder is 20-85 μm; preferably, the particle size of the mineralizer is 0.1-5 μm. The photosensitive resin is one or more of trimethylolpropane triacrylate, trimethylpropane triacrylate, tripropylene glycol diacrylate, and 1,6-hexanediol diacrylate; preferably, the photoinitiator is one or more of 2-hydroxy-2-methyl-1-phenylacetone-1, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide; preferably, the dispersant is one or more of sodium hexametaphosphate, sodium polyacrylate, ammonium polyacrylate, and polyvinylpyrrolidone; preferably, the framework powder is silica and / or fused glass powder. The mineralizing agent is silica and / or chromium silicate.

[0089] The process parameters for the photopolymerization printing process are as follows: printing layer thickness is 50-200μm, and laser power is 3-45mW / cm². 2 The scanning speed is 800-2000 mm / s.

[0090] The degreasing process includes: heating the raw blank from room temperature to 230-350°C at a heating rate of 1-2°C / min in an air atmosphere, and holding it at 230-350°C for 240-360min; then heating it to 450-630°C at a heating rate of 0.5-1.5°C / min, and holding it at 450-630°C for 360-720min; and then cooling it back to room temperature at a cooling rate of 1-3°C / min.

[0091] The sintering process includes: in a protective atmosphere with a gas pressure of 0.1-0.3 MPa, heating the degreased green blank from room temperature to 1000-1100℃ at a heating rate of 3-8℃ / min, and holding it at 1000-1100℃ for 360-720 min; then heating it to 1150-1300℃ at a heating rate of 1-2℃ / min, and holding it at 1150-1300℃ for 240-480 min; then cooling it to 500℃ at a cooling rate of 2-5℃ / min, and after furnace cooling, obtaining a ceramic core specimen with a lattice topology.

[0092] Step 4): Based on the ceramic core specimen with lattice topology, a turbine blade specimen with lattice topology is prepared.

[0093] The ceramic core specimen is pressed into a wax mold, and then successively undergoes shell preparation, single crystal blade precision casting, shell removal-core removal, heat treatment, and polishing to obtain the turbine blade specimen.

[0094] Step 5): Test the turbine blade specimen with the lattice topology (including cold effect test, tensile strength test, and relative density test), and compare the test data with the simulation results in Step 2); based on the comparison results, perform final optimization and shaping of the digital model of the three-dimensional lattice topology structure that is symbiotic with the internal cavity shape of the turbine blade to obtain the final model of the turbine blade.

[0095] Step 6): Based on the final model of the turbine blade, reverse structure design is performed to obtain an optimized ceramic core model; based on the optimized ceramic core model, a ceramic core is fabricated using photopolymerization 3D printing technology; based on the ceramic core, a turbine blade with a lattice topology structure is fabricated.

[0096] The inventiveness of the above-mentioned solution of the present invention is mainly reflected in the following three aspects:

[0097] 1) Revolutionary Improvement in Cooling Efficiency: The lattice topology provides a significantly larger specific surface area than traditional turbulence columns, greatly enhancing convective heat transfer between the cooling airflow and the blade wall. The complex, three-dimensionally interconnected flow channels effectively disrupt the laminar boundary layer of the cooling air, promoting turbulence and significantly improving the heat transfer coefficient. The lattice structure enables uniform distribution of the cooling medium in three-dimensional space, avoiding localized overheating and effectively reducing the overall temperature gradient and thermal stress of the blade.

[0098] 2) Design Iteration and Rapid Verification: A new generation of rapid verification and finalization technology for complex internal cavity turbine blades based on photopolymer additive ceramic cores has been pioneered. This approach breaks through the capability and cycle bottlenecks of traditional mold manufacturing, realizing "design as manufacturing" for innovative cooling structures such as high-performance single-crystal blade lattice topology. Through the combination of digital model design optimization and photopolymer additive manufacturing processes, the cycle from conceptual design to qualified casting of the blade internal cavity has been shortened by orders of magnitude. This not only achieves a leap in blade cooling effect but also establishes an agile development process from digital model to prototype, laying the foundation for rapid iteration and performance leaps in the next generation of high-performance blades.

[0099] 3) Synergistic improvement in lightweight and strength: While ensuring cooling performance, the lattice structure itself is an efficient lightweight structure, which helps to reduce the weight of the blades. In addition, a reasonable lattice design can maintain good structural stiffness and strength, preventing the blades from deforming or failing during casting and service.

[0100] The present invention will be further illustrated below with specific embodiments:

[0101] Example 1

[0102] This embodiment provides a fabrication process for a lattice topology turbine blade based on a photocurable ceramic core, which mainly includes the following steps:

[0103] Step 1): With the goal of improving the cooling efficiency of turbine blades, parametric modeling and computational fluid dynamics optimization of the lattice topology are performed to generate a digital model of the three-dimensional lattice topology that is symbiotic with the internal cavity shape of the turbine blade. This yields an initial design model of the turbine blade with the lattice topology (a truss lattice structure unit is set in the turbine blade body, the unit cell is divided into 8 small cubes, each cube defines 27 nodes, the defined nodes are connected to construct an orthogonal anisotropic symmetric truss lattice structure unit, multiple nodes are added in the small cube unit cell to generate a truss lattice structure unit, and multiple rod diameters are filled to generate a digital model of the three-dimensional lattice topology that is symbiotic with the internal cavity shape of the turbine blade).

[0104] Specifically, by controlling the lattice porosity to 0.7, multiple nodes were added within a small cubic unit cell to generate a truss lattice structure. This structure was then filled with multiple rod diameters to create a digital model of a three-dimensional lattice topology that coexists with the internal shape of the turbine blade, thus obtaining an initial design model of the turbine blade with this lattice topology. Relevant data were extracted using Fluent, and post-processing was performed using Matlab and Tecplot. The heat transfer coefficient Nu / Nu0 was calculated to be 5.2 and the flow resistance coefficient f / f0 to be 48 for different lattice topologies, completing the fluid dynamics calculations.

[0105] Step 2): Simulate and verify the initial design model of the turbine blade to obtain an optimized turbine blade model that meets the preset cooling efficiency index of 0.82 and tensile strength index of 860MPa.

[0106] Specifically, lattice elements are set in the blade body of the turbine blade. By controlling the number of rods (2-6) and the topological structure (2-6 node elements), multiple configuration combinations are achieved to perform coupled simulations of fluid dynamics and structural mechanics for different structures, obtaining flow field distribution data and heat transfer coefficient data. A typical computational domain model of inlet section—test section—outlet section is set up. By comparing the drag, Nusselt number ratio, and comprehensive heat transfer factor at different Reynolds numbers, a turbine blade optimization model with six nodes and a 3-bar lattice structure that meets the preset cooling performance and structural strength thresholds is obtained.

[0107] Step 3): Based on the turbine blade optimization model, perform inverse structure design to obtain the ceramic core model (wherein, Figure 3 Figure a in the figure is the design drawing of the photopolymer ceramic core model in Example 1; based on the ceramic core model, a ceramic core specimen with a lattice topology was prepared by photopolymer 3D printing technology.

[0108] In this step, based on the turbine blade optimization model, tetrahedral lattice topology units are used ( Figure 4 Figure b in the figure is an enlarged view of the unit cell of the lattice topology structure in Example 1. The included angle of the unit bar diameter is 45° and the bar diameter is 0.8 mm. A three-dimensional lattice topology ceramic core model was designed. Based on the above ceramic core model, ceramic core specimens were prepared using the following method:

[0109] 480g of silica powder with a particle size of 40μm and 120g of zirconium silicate powder with a particle size of 3μm were stirred uniformly at 300rpm for 120min using a mechanical stirrer to obtain a solid powder. 480g of trimethylpropane triacrylate, 72g of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, and 48g of sodium hexametaphosphate were stirred at 35℃ for 30min to obtain a liquid solvent. The solid powder was added to the liquid solvent to obtain a mixture; the mixture was then placed in a ball mill and stirred at 380rpm for 240min to obtain a ceramic core slurry.

[0110] A ceramic core blank was obtained by photopolymerization of a ceramic 3D printer. The printing parameters included a layer thickness of 100 μm and a laser power of 20 mW / cm². 2 The scanning rate is 1500 mm / s.

[0111] The ceramic core blank was degreased and sintered to obtain a ceramic core specimen with a lattice topology. Figure 5 Figure a in the figure is a physical image of the ceramic core specimen with a lattice topology structure of Example 1.

[0112] The degreasing treatment conditions are as follows: In an air atmosphere, the photocured preform is heated from room temperature to 300℃ at a heating rate of 1℃ / min and held at 300℃ for 360min; then heated to 550℃ at a heating rate of 0.5℃ / min and held at 550℃ for 720min; and then cooled to room temperature at a cooling rate of 1℃ / min.

[0113] The sintering conditions were as follows: in an Ar protective atmosphere with a gas pressure of 0.2 MPa, the degreased green body was heated from room temperature to 1000℃ at a heating rate of 5℃ / min and held at 1000℃ for 480 min; then heated to 1200℃ at a heating rate of 1.5℃ / min and held at 1200℃ for 480 min; then cooled to 500℃ at a cooling rate of 3℃ / min and cooled in the furnace to obtain a ceramic core specimen with a lattice topology.

[0114] Step 4): Combine the ceramic core specimen with the lattice topology with the wax model to prepare the shell. Use DD5 single crystal material, 2.7 kg, upper zone temperature 1470℃, lower zone temperature 1520℃, pouring temperature 1520℃, standing time 5 min, and pulling rate 4 mm / min for casting. After core removal, heat treatment and polishing, the turbine blade specimen with the lattice topology is finally obtained.

[0115] Step 5): The cooling effect, tensile strength and relative density of the turbine blade specimen with the lattice topology are tested, and the test data are compared with the simulation results in Step 2). Based on the comparison results, the digital model of the three-dimensional lattice topology structure coexisting with the inner cavity shape of the turbine blade is finally optimized and finalized to obtain the final model of the turbine blade.

[0116] Step 6): Based on the final model of the turbine blade, reverse structure design is performed to obtain an optimized ceramic core model; based on the optimized ceramic core model, a ceramic core is fabricated using photopolymerization 3D printing technology; based on the ceramic core, a turbine blade with a lattice topology structure is fabricated. Figure 6 This is a front view of the turbine blade with a lattice topology in Example 1; Figure 7 Figure a in the figure is a top view of the inner cavity of the turbine blade with the lattice topology structure in Example 1.

[0117] The reverse structure design, photopolymerization 3D printing process parameters, sintering and degreasing treatment parameters in this step are described in step 3; the process parameters for the step of preparing turbine blades based on ceramic cores are described in step 4.

[0118] Example 2

[0119] This embodiment provides a fabrication process for a lattice topology turbine blade based on a photocurable ceramic core, which mainly includes the following steps:

[0120] Step 1): With the goal of improving the cooling efficiency of turbine blades, parametric modeling and computational fluid dynamics optimization of the lattice topology are performed to generate a digital model of the three-dimensional lattice topology that is symbiotic with the internal cavity shape of the turbine blade. This yields an initial design model of the turbine blade with the lattice topology (a truss lattice structure unit is set in the turbine blade body, the unit cell is divided into 8 small cubes, each cube defines 27 nodes, the defined nodes are connected to construct an orthogonal anisotropic symmetric truss lattice, multiple nodes are added in the small cube unit cell to generate the truss lattice structure, and multiple rod diameters are filled to generate a digital model of the three-dimensional lattice topology that is symbiotic with the internal cavity shape of the turbine blade).

[0121] Specifically, by controlling the lattice porosity to 0.7, multiple nodes were added within a small cubic unit cell to generate a truss lattice structure. This structure was then filled with multiple rod diameters to create a digital model of a three-dimensional lattice topology that coexists with the internal shape of the turbine blade, thus obtaining an initial design model of the turbine blade with this lattice topology. Relevant data were extracted using Fluent, and post-processing was performed using Matlab and Tecplot. The heat transfer coefficient Nu / Nu0 was calculated to be 4.7 and the flow resistance coefficient f / f0 to be 43 for different lattice topologies, completing the fluid dynamics calculations.

[0122] Step 2): Simulate and verify the initial design model of the turbine blade to obtain an optimized turbine blade model that meets the preset cooling efficiency index of 0.82 and tensile strength index of 860MPa (a turbine blade optimized model that meets the preset cooling performance and structural strength thresholds and is filled with a 3-bar lattice structure).

[0123] Specifically, by controlling the number of rods (2-6) and the topology (2-6 node elements), multiple configuration combinations are achieved to perform coupled simulations of fluid dynamics and structural mechanics for different structures, obtaining flow field distribution data and heat transfer coefficient data; a typical computational domain model of inlet section—test section—outlet section is set up. By comparing the drag, Nusselt number ratio, and comprehensive heat transfer factor at different Reynolds numbers, four nodes that meet the preset cooling performance and structural strength thresholds are obtained, filling a turbine blade optimization model with a 3-bar lattice structure.

[0124] Step 3): Based on the turbine blade optimization model, perform inverse structure design to obtain the ceramic core model (wherein, Figure 3 Figure b in the figure is the design diagram of the photopolymer ceramic core model in Example 2); based on the ceramic core model, a ceramic core specimen with a lattice topology was prepared by using photopolymer 3D printing technology.

[0125] Among them, based on the turbine blade optimization model, tetrahedral lattice topology unit is adopted ( Figure 4 Figure c in the figure is an enlarged view of the unit of the lattice topology structure in Example 2. The included angle of the unit rod diameter is 30° and the rod diameter is 1mm. A three-dimensional ceramic digital model of the lattice topology structure is designed.

[0126] In this process, 540g of silica powder with a particle size of 60μm and 600g of zirconium silicate powder with a particle size of 5μm were stirred uniformly at 300rpm for 120min using a mechanical stirrer to obtain a solid powder. 540g of trimethylpropane triacrylate, 30g of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, and 30g of sodium hexametaphosphate were stirred at 35℃ for 30min to obtain a liquid solvent. The solid powder was added to the liquid solvent to obtain a mixture. The mixture was then placed in a ball mill and stirred at 380rpm for 240min to obtain a ceramic core slurry.

[0127] Among them, a photopolymer ceramic 3D printer was used to photopolymerize ceramic core slurry onto a lattice topology ceramic core to prepare a photopolymerized lattice topology ceramic core blank. The printing parameters included: a printing layer thickness of 150μm and a power of 30mW / cm². 2 The scanning rate is 2000 mm / s.

[0128] In this process, the photocurable ceramic core blank is degreased and sintered to obtain a photocurable additive manufacturing ceramic core.

[0129] The degreasing treatment conditions are as follows: In an air atmosphere, the photocured preform is heated from room temperature to 300℃ at a heating rate of 1.5℃ / min and held at 300℃ for 300min; then heated to 550℃ at a heating rate of 1℃ / min and held at 550℃ for 480min; and then cooled to room temperature at a cooling rate of 2℃ / min.

[0130] The sintering conditions were as follows: In an Ar protective atmosphere with a gas pressure of 0.1 MPa, the degreased green body was heated from room temperature to 1000℃ at a heating rate of 3℃ / min and held at 1000℃ for 720 min; then heated to 1200℃ at a heating rate of 1℃ / min and held at 1200℃ for 480 min; finally cooled to 500℃ at a cooling rate of 2℃ / min, and cooled in the furnace to obtain a ceramic core specimen with a lattice topology. Figure 5 Figure b in the figure is a physical image of the ceramic core specimen with a lattice topology structure of Example 2.

[0131] Step 4): Combine the ceramic core specimen with the lattice topology with the wax model to prepare the shell. Use DD5 single crystal material, 3.5 kg, upper zone temperature 1470℃, lower zone temperature 1520℃, pouring temperature 1520℃, standing time 5 min, and pulling rate 4 mm / min for casting. After core removal, heat treatment and polishing, the lattice topology single crystal turbine blade is finally obtained.

[0132] Step 5): The cooling effect, tensile strength and relative density of the turbine blade specimen with the lattice topology are tested, and the test data are compared with the simulation results in Step 2). Based on the comparison results, the digital model of the three-dimensional lattice topology structure coexisting with the inner cavity shape of the turbine blade is finally optimized and finalized to obtain the final model of the turbine blade.

[0133] Step 6): Based on the final model of the turbine blade, reverse structure design is performed to obtain an optimized ceramic core model; based on the optimized ceramic core model, a ceramic core is fabricated using photopolymerization 3D printing technology; based on the ceramic core, a turbine blade with a lattice topology structure is fabricated. Figure 7 Figure b in the figure is a top view of the inner cavity of the turbine blade with the lattice topology structure in Example 2.

[0134] The reverse structure design, photopolymerization 3D printing process parameters, sintering and degreasing treatment parameters in this step are described in step 3; the process parameters for the step of preparing turbine blades based on ceramic cores are described in step 4.

[0135] Example 3

[0136] This embodiment provides a fabrication process for a lattice topology turbine blade based on a photocurable ceramic core, which mainly includes the following steps:

[0137] Step 1): With the goal of improving the cooling efficiency of turbine blades, parametric modeling and computational fluid dynamics optimization of the lattice topology are performed to generate a digital model of the three-dimensional lattice topology that is symbiotic with the internal cavity shape of the turbine blade. This yields an initial design model of the turbine blade with the lattice topology (a truss lattice structure unit is set in the turbine blade body, the unit cell is divided into 8 small cubes, each cube defines 27 nodes, the defined nodes are connected to construct an orthogonal anisotropic symmetric truss lattice, multiple nodes are added in the small cube unit cell to generate the truss lattice structure, and multiple rod diameters are filled to generate a digital model of the three-dimensional lattice topology that is symbiotic with the internal cavity shape of the turbine blade).

[0138] By controlling the lattice porosity to 0.7, multiple nodes were added within a small cubic unit cell to generate a truss lattice structure. A digital model of a three-dimensional lattice topology, co-existing with the internal cavity shape of the turbine blade, was created by filling multiple rod diameters, thus obtaining an initial design model of the turbine blade with the lattice topology. Relevant data were extracted using Fluent, and post-processing was performed using Matlab and Tecplot. The heat transfer coefficient Nu / Nu0 was calculated to be 4.8 and the flow resistance coefficient f / f0 to be 43 for different lattice topologies, completing the fluid dynamics calculations.

[0139] Step 2): Simulate and verify the initial design model of the turbine blade to obtain an optimized turbine blade model that meets the preset cooling efficiency index of 0.82 and tensile strength index of 860MPa (a turbine blade optimized model that meets the preset cooling performance and structural strength thresholds and is filled with a 2-bar lattice structure).

[0140] Specifically, by controlling the number of rods (2-6) and the topology (2-6 node elements), multiple configuration combinations are achieved to perform coupled simulations of fluid dynamics and structural mechanics for different structures, obtaining flow field distribution data and heat transfer coefficient data; a typical computational domain model of inlet section—test section—outlet section is set up. By comparing the drag, Nusselt number ratio, and comprehensive heat transfer factor at different Reynolds numbers, four nodes that meet the preset cooling performance and structural strength thresholds are obtained, filling a turbine blade optimization model with a 2-bar lattice structure.

[0141] Step 3): Based on the turbine blade optimization model, inverse structure design is performed to obtain a ceramic core model; based on the ceramic core model, a ceramic core specimen with a lattice topology is prepared using photopolymerization 3D printing technology (wherein, Figure 3 Figure c in the figure is the design drawing of the photocurable ceramic core model in Example 3.

[0142] Among them, based on the turbine blade optimization model, tetrahedral lattice topology unit is adopted ( Figure 4 Figure a in the figure is an enlarged view of the unit of the lattice topology structure in Example 3. The included angle of the unit rod diameter is 60° and the rod diameter is 0.5mm. A three-dimensional lattice topology ceramic core model is designed.

[0143] In this process, 420g of silica powder with a particle size of 20μm and 180g of zirconium silicate powder with a particle size of 1μm were stirred uniformly at 350rpm for 180min using a mechanical stirrer to obtain a solid powder. 420g of trimethylpropane triacrylate, 120g of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, and 60g of sodium hexametaphosphate were stirred at 35℃ for 30min to obtain a liquid solvent. The solid powder was added to the liquid solvent to obtain a mixture. The mixture was then placed in a ball mill and stirred at 380rpm for 180min to obtain a ceramic core slurry.

[0144] Among them, a photopolymer ceramic 3D printer was used to photopolymerize ceramic core slurry onto a lattice topology ceramic core to prepare a photopolymerized lattice topology ceramic core blank. The printing parameters included: a printing layer thickness of 50μm and a power of 10mW / cm². 2 The scanning rate is 1200 mm / s.

[0145] In this process, the photocurable ceramic core blank is degreased and sintered to obtain a photocurable additive manufacturing ceramic core.

[0146] The degreasing treatment conditions are as follows: in an air atmosphere, the photocured preform is heated from room temperature to 350°C at a heating rate of 2°C / min and held at 350°C for 240 min; then heated to 550°C at a heating rate of 1.5°C / min and held at 550°C for 360 min; and then cooled to room temperature at a cooling rate of 3°C / min.

[0147] The sintering conditions were as follows: in an Ar protective atmosphere with a gas pressure of 0.3 MPa, the degreased green body was heated from room temperature to 1000℃ at a heating rate of 8℃ / min and held at 1000℃ for 360 min; then heated to 1200℃ at a heating rate of 2℃ / min and held at 1200℃ for 240 min; then cooled to 500℃ at a cooling rate of 5℃ / min and cooled in the furnace to obtain a ceramic core specimen with a lattice topology.

[0148] Step 4): Combine the ceramic core with the wax model to prepare the shell. Use DD5 single crystal material, 3.0 kg, upper zone temperature 1470℃, lower zone temperature 1520℃, pouring temperature 1520℃, settling time 5 min, and pulling rate 4 mm / min for casting. After core removal, heat treatment, and polishing, a turbine blade specimen with a lattice topology structure of photocured ceramic core is finally obtained. Figure 5 Figure c in the figure is a physical image of the ceramic core specimen with a lattice topology structure of Example 3.

[0149] Step 5): The cooling effect, tensile strength and relative density of the turbine blade specimen with the lattice topology are tested, and the test data are compared with the simulation results in Step 2). Based on the comparison results, the digital model of the three-dimensional lattice topology structure coexisting with the inner cavity shape of the turbine blade is finally optimized and finalized to obtain the final model of the turbine blade.

[0150] Step 6): Based on the final model of the turbine blade, reverse structure design is performed to obtain an optimized ceramic core model; based on the optimized ceramic core model, a ceramic core is fabricated using photopolymerization 3D printing technology; based on the ceramic core, a turbine blade with a lattice topology structure is fabricated. Figure 7 Figure c in the figure is a top view of the inner cavity of the turbine blade with the lattice topology structure in Example 3.

[0151] The reverse structure design, photopolymerization 3D printing process parameters, sintering and degreasing treatment parameters in this step are described in step 3; the process parameters for the step of preparing turbine blades based on ceramic cores are described in step 4.

[0152] Comparative Example 1

[0153] Comparative Example 1 prepared a single-crystal turbine blade. The only difference between Comparative Example 1 and Example 1 is that Comparative Example 1 prepared a double-walled cold single-crystal turbine blade (the turbine blade of Example 1 has a lattice topology cooling structure, while the turbine blade of Comparative Example 1 has a double-walled cooling structure). The main steps include the following:

[0154] 1) Mix 480g of silica powder with a particle size of 40μm and 120g of zirconium silicate powder with a particle size of 3μm using a mechanical stirrer at 300rpm for 120min until homogeneous. Take 480g of trimethylpropane triacrylate, 72g of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, and 48g of sodium hexametaphosphate and stir at 35℃ for 30min. Then add the mixed powder obtained in step 1) to the mixture and place the mixture in a ball mill and stir at 380rpm for 240min.

[0155] 2) A photopolymer ceramic 3D printer was used to photopolymerize a ceramic core slurry onto a double-walled cold-structured ceramic core to obtain a photopolymerized double-walled ceramic core blank. The printing parameters included: a printing layer thickness of 150 μm and a power of 25 mW / cm². 2 Scanning rate 3000 mm / s.

[0156] 3) The photocurable ceramic core blank from step 2) is degreased and sintered to obtain a photocurable additive manufacturing ceramic core.

[0157] The degreasing treatment conditions are as follows: in an air atmosphere, the photocured preform is heated from room temperature to 400℃ at a heating rate of 1℃ / min and held at 400℃ for 360min; then heated to 600℃ at a heating rate of 0.5℃ / min and held at 600℃ for 720min; and then cooled to room temperature at a cooling rate of 1℃ / min.

[0158] The sintering conditions are as follows: In an Ar protective atmosphere with a gas pressure of 0.25 MPa, the degreased green body is heated from room temperature to 1000℃ at a heating rate of 5℃ / min and held at 1000℃ for 480 min; then heated to 1200℃ at a heating rate of 2℃ / min and held at 1200℃ for 480 min; then cooled to 500℃ at a cooling rate of 5℃ / min and cooled in the furnace to obtain a double-walled ceramic core.

[0159] 4) Combine the ceramic core with the wax mold to prepare the shell. Use DD5 single crystal material, 3.5kg, upper zone temperature 1480℃, lower zone temperature 1520℃, pouring temperature 1520℃, standing time 5min, and pulling rate 5mm / min for casting. Then, after core removal, shell removal, heat treatment and polishing, the double-walled cold single crystal turbine blade is finally obtained.

[0160] 5) The cooling efficiency, tensile strength and relative density of the double-walled cold single-crystal turbine blade specimen were tested.

[0161] Comparative Example 2

[0162] Comparative Example 2 prepared a single-crystal turbine blade. The only difference between Comparative Example 2 and Example 1 is that the double-walled cooled single-crystal turbine blade prepared in Comparative Example 2 has complex film cooling pores (compared to Comparative Example 1, the turbine blade of Comparative Example 2 has film cooling pores processed on the basis of the double-walled cooled structure). The main steps include the following:

[0163] 1) Mix 480g of silica powder with a particle size of 40μm and 120g of zirconium silicate powder with a particle size of 3μm using a mechanical stirrer at 300rpm for 120min until homogeneous. Take 480g of trimethylpropane triacrylate, 72g of 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, and 48g of sodium hexametaphosphate and stir at 35℃ for 30min. Then add the mixed powder obtained in step 1) to the mixture and place the mixture in a ball mill and stir at 380rpm for 240min.

[0164] 2) A photopolymer ceramic 3D printer was used to photopolymerize ceramic core slurry onto a complex layered cold-structure ceramic core to obtain a photopolymerized complex layered cold-structure ceramic core blank. The printing parameters included: a printing layer thickness of 160 μm and a power of 28 mW / cm². 2 Scanning rate 3500mm / s.

[0165] 3) The photocurable ceramic core blank from step 2) is degreased and sintered to obtain a photocurable additive manufacturing ceramic core.

[0166] The degreasing treatment conditions are as follows: In an air atmosphere, the photocured preform is heated from room temperature to 400℃ at a heating rate of 0.5℃ / min and held at 400℃ for 480min; then heated to 600℃ at a heating rate of 0.3℃ / min and held at 600℃ for 720min; and then cooled to room temperature at a cooling rate of 1℃ / min.

[0167] The sintering conditions are as follows: In an Ar protective atmosphere with a gas pressure of 0.2 MPa, the degreased green body is heated from room temperature to 800℃ at a heating rate of 5℃ / min and held at 800℃ for 480 min; then heated to 1200℃ at a heating rate of 2℃ / min and held at 1200℃ for 720 min; then cooled to 500℃ at a cooling rate of 5℃ / min and cooled in the furnace to obtain a double-walled cold-structure ceramic core.

[0168] 4) Combine the ceramic core with the wax model to prepare the shell. Use DD5 single crystal material, 4.0 kg, upper zone temperature 1470℃, lower zone temperature 1520℃, pouring temperature 1520℃, standing time 5 min, and pulling rate 4 mm / min for casting. After core removal, shell removal, heat treatment and polishing, film pore processing is performed to finally obtain a single crystal turbine blade with double wall and film pore structure.

[0169] 5) The cooling effect, tensile strength and relative density of the single crystal turbine blade specimen were tested.

[0170] Table 1 shows the test data of cooling efficiency, tensile strength and relative density of the single crystal turbine blades prepared in Examples 1-3 and Comparative Examples 1-2.

[0171] Table 1

[0172]

[0173] In Table 1, "relative density" refers to the ratio of the volume occupied by solid material in the blade to the total volume of the blade's outer contour. It directly reflects the balance between "lightweight" and "structural strength." Higher relative density means more material and higher strength, but also greater weight. Lower relative density indicates a larger total volume of cooling channels and cavities inside the blade, resulting in greater cooling efficiency.

[0174] As can be seen from Table 1, the single-crystal blades prepared by the embodiment of the present invention through lattice topology design and photopolymer additive manufacturing of ceramic cores have improved cooling efficiency. While ensuring the cooling effect, the reasonable lattice design enables the single-crystal blades to maintain good structural strength, avoid deformation or failure during casting and service, and also help to reduce the weight of the blades.

[0175] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A fabrication process for a turbine blade with a lattice topology structure based on a photocurable ceramic core, characterized in that, It includes the following steps: Step 1): With the goal of improving the cooling efficiency of turbine blades, parametric modeling and computational fluid dynamics optimization of the lattice topology are performed to generate a digital model of the three-dimensional lattice topology that is symbiotic with the internal cavity shape of the turbine blade, and to obtain the initial design model of the turbine blade with the lattice topology. Step 2): Simulate and verify the initial design model of the turbine blade to obtain an optimized turbine blade model that meets the preset cooling performance and structural strength thresholds; Step 3): Based on the turbine blade optimization model, reverse structure design is performed to obtain a ceramic core model; based on the ceramic core model, a ceramic core specimen with a lattice topology is prepared using photopolymerization 3D printing technology. Step 4): Based on the ceramic core specimen with lattice topology, a turbine blade specimen with lattice topology is prepared; Step 5): The turbine blade specimen with the lattice topology is tested, and the test data is compared with the simulation results in Step 2). Based on the comparison results, the digital model of the three-dimensional lattice topology structure that is symbiotic with the inner cavity shape of the turbine blade is finally optimized and finalized to obtain the final model of the turbine blade. Step 6): Based on the final model of the turbine blade, reverse structure design is performed to obtain an optimized ceramic core model; based on the optimized ceramic core model, a ceramic core is fabricated using photopolymerization 3D printing technology; based on the ceramic core, a turbine blade with a lattice topology structure is fabricated.

2. The fabrication process of the turbine blade based on the lattice topology structure of the photocurable ceramic core according to claim 1, characterized in that, In step 1): When performing parametric modeling of the lattice topology, dense lattice elements are used for a defined region of the turbine blade, and the element angles and rod diameters are optimized. Preferably, the defined region includes one or more parts of the turbine blade's leading edge, blade body, tip, and trailing edge. Preferably, the dense lattice elements include any one or more of Gyroid surfaces, octahedrons, and truss lattice structures. And / or Rapid parametric modeling of lattice topology structures is achieved through a two-stage control approach: first selecting the topology, then adjusting the parameters. This allows for the acquisition of geometric variants with different relative densities and mechanical and thermal properties under the same lattice topology. The influence on pore flow velocity is then analyzed by calculating lattice flow heat transfer performance. The heat transfer coefficient ratio is linked to the pump power ratio using Reynolds analogy, allowing for the calculation of heat transfer effects and flow resistance for different lattice topologies, thereby achieving computational fluid dynamics optimization. Preferably, the two-stage control approach involves: selecting optimal lattice topology units according to an efficient cooling model, and then optimizing the heat transfer effect and flow resistance of the lattice topology by adjusting the rod diameter and unit angle, thus completing the fluid dynamics optimization.

3. The fabrication process of the turbine blade based on the lattice topology structure of the photocurable ceramic core according to claim 1, characterized in that, Step 2) includes: Step 21): Based on the initial design model of the turbine blade, construct a parametric lattice topology 3D model library; Step 22): Based on the parameterized lattice topology 3D model library, perform coupled fluid dynamics and structural mechanics simulation to obtain simulation data; preferably, the simulation data includes flow field distribution data, heat transfer coefficient data and structural stress field data; Step 23): Based on the simulation data, with the optimization objectives of maximizing cooling efficiency and minimizing maximum flow resistance, perform multiple rounds of iterative optimization on the unit configuration, rod diameter and angle of the lattice topology in the initial design model of the turbine blade to obtain a turbine blade optimization model that meets the preset cooling performance and structural strength thresholds. Preferably, in step 21): the porosity of the lattice structure is controlled, different types of truss lattices are defined as cooling structures to construct a dataset, two nodes, four nodes, and six nodes are added in the cubic unit cell to generate the required truss lattice structure, and multiple configuration combinations are achieved by controlling the number of rods and the lattice topology, and a three-dimensional model database of the lattice topology is systematically constructed. Preferably, in step 22), fluid dynamics and structural mechanics coupled simulation is performed using Fluent software; Preferably, in step 23), the flow resistance refers to the flow resistance to heat flow. Preferably, in step 23), the preset cooling performance includes: comprehensive cooling efficiency ≥ 0.8; the structural strength threshold includes: tensile strength ≥ 0.8; more preferably, the comprehensive cooling efficiency refers to the dimensionless temperature calculation of the metal substrate surface, and the calculation formula is as follows: ； Among them, T g Mainstream gas temperature; T m : The actual surface temperature of the cooled metal wall; T c,in : Coolant inlet temperature.

4. The fabrication process of the turbine blade based on the lattice topology structure of the photocurable ceramic core according to claim 1, characterized in that, In step 3): Based on the turbine blade optimization model, a 3D modeling software is used for inverse structural design to create a 3D model of the ceramic core; and / or The lattice units of the lattice topology structure on the ceramic core model are tetrahedral or octahedral, with an included angle of 30-60° and a rod diameter of 0.5-1mm.

5. The fabrication process of the turbine blade based on the lattice topology structure of the photocurable ceramic core according to claim 1, characterized in that, In step 3): The ceramic core model is imported into a photopolymer additive manufacturing system, and the ceramic core slurry is subjected to photopolymer 3D printing to obtain a green blank. The green blank is then degreased and sintered to obtain a ceramic core specimen with a lattice topology.

6. The fabrication process of the turbine blade based on the lattice topology structure of the photocurable ceramic core according to claim 5, characterized in that, In step 3), By volume fraction, the ceramic core slurry comprises 35%-45% liquid solvent and 55%-65% solid powder; wherein the liquid solvent comprises: 79-90 parts by volume of photosensitive resin, 5-20 parts by volume of photoinitiator, and 5-10 parts by volume of dispersant; wherein the solid powder comprises: 70-90 parts by weight of skeleton powder and 10-30 parts by weight of mineralizer. Preferably, the particle size of the skeleton powder is 20-85 μm; Preferably, the particle size of the mineralizer is 0.1-5 μm; Preferably, the photosensitive resin is one or more of trimethylolpropane triacrylate, trimethylpropane triacrylate, tripropylene glycol diacrylate, and 1,6-hexanediol diacrylate. Preferably, the photoinitiator is one or more of 2-hydroxy-2-methyl-1-phenylacetone-1, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, and 2,4,6-trimethylbenzoyl-diphenylphosphine oxide; Preferably, the dispersant is one or more of sodium hexametaphosphate, sodium polyacrylate, ammonium polyacrylate, and polyvinylpyrrolidone; Preferably, the skeleton powder is silicon dioxide and / or molten glass powder; Preferably, the mineralizing agent is silicon dioxide and / or chromium silicate.

7. The fabrication process of the turbine blade based on the lattice topology structure of the photocurable ceramic core according to claim 5, characterized in that, In step 3): The process parameters for the photopolymerization printing process are as follows: printing layer thickness is 50-200μm, and laser power is 3-45mW / cm². 2 The scanning speed is 800-2000 mm / s; and / or The degreasing process includes: heating the raw blank from room temperature to 230-350°C at a heating rate of 1-2°C / min in an air atmosphere, and holding it at 230-350°C for 240-360 min; then heating it to 450-630°C at a heating rate of 0.5-1.5°C / min, and holding it at 450-630°C for 360-720 min; then cooling it back to room temperature at a cooling rate of 1-3°C / min; and / or The sintering process includes: in a protective atmosphere with a gas pressure of 0.1-0.3 MPa, heating the degreased green blank from room temperature to 1000-1100℃ at a heating rate of 3-8℃ / min, and holding it at 1000-1100℃ for 360-720 min; then heating it to 1150-1300℃ at a heating rate of 1-2℃ / min, and holding it at 1150-1300℃ for 240-480 min; then cooling it to 450-500℃ at a cooling rate of 2-5℃ / min, and after furnace cooling, obtaining a ceramic core specimen with a lattice topology.

8. The fabrication process of the turbine blade based on the lattice topology structure of the photocurable ceramic core according to claim 1, in step 4): The ceramic core specimen with lattice topology is pressed into a wax pattern to prepare a shell; the shell is then cast; the cast part is then deshelled and decored to obtain a turbine blade casting; the turbine blade casting is then heat-treated and polished to obtain a turbine blade specimen with lattice topology. Preferably, the turbine blade specimen with a lattice topology is a single-crystal turbine blade.

9. The fabrication process of the turbine blade based on the lattice topology structure of the photocurable ceramic core according to claim 1, in step 5): The tests performed on the turbine blade specimen with the lattice topology include cooling effect testing, tensile strength testing, and relative density testing.

10. The fabrication process of the turbine blade based on the lattice topology structure of the photocurable ceramic core according to claim 5), in step 5): Based on the comparison results, the digital model of the three-dimensional lattice topology is finally optimized and finalized. Preferably, based on the performance test data of the turbine blade specimen, the lattice topology with the best performance is selected for model finalization; Preferably, the performance test data includes cold effect test data, tensile strength test data, and relative density test data.

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