Turbine rotor blade and method of manufacturing the same

Abstract

The present application relates to a kind of turbine rotor blade and its preparation method.The turbine rotor blade includes: blade main body, with first wall thickness, the blade main body has internal cavity;And dot matrix structure, filled in the internal cavity, the dot matrix structure includes multiple struts, the strut has first diameter, and the included angle of the strut relative to the plane of additive manufacturing formation meets self-supporting formation inclination condition;Wherein, the ratio of the first wall thickness and the first diameter is in preset matching range, the blade main body and the dot matrix structure are integrally formed by nickel-based superalloy.This application can solve the problem that hollow dot matrix component is sensitive to microcell parameter in the process of additive manufacturing, prone to forming defects and difficult to realize no support integration in prior art.

Description

Technical Field

[0001] This invention relates to the field of aero-engine turbine design and additive manufacturing technology, and in particular to a turbine rotor blade and its preparation method. Background Technology

[0002] In related technologies, the lightweight design of turbine rotor blades for aero-engines typically employs a hollow structure filled with lattice or crystal structures to maintain mechanical properties.

[0003] However, existing additive manufacturing solutions for hollow lattice components often rely heavily on precise control of microscopic parameters such as lattice cell size, spacing, and volume fraction. In practical engineering applications, this strong dependence on microscopic parameters leads to the following technical problems: On the one hand, the complex control of microscopic parameters makes data exchange and collaborative verification between designers and manufacturers extremely difficult, making it hard to adapt to the division of labor and cooperation in industrialized production; on the other hand, if the microscopic parameters do not match the thermal conductivity of the thin-walled structure, local heat accumulation is easily generated during selective laser melting, leading to molten pool instability, crack initiation, or warping deformation. This forces the manufacturing process to rely on a large number of internal support structures, but removing the supports within the complex cavity is not only costly but also impossible.

[0004] Therefore, there is an urgent need for a turbine rotor blade and its preparation method that can reduce the sensitivity to microscopic cell parameters, achieve unsupported integrated molding, and possess excellent mechanical properties. Summary of the Invention

[0005] The present invention provides a turbine rotor blade and its preparation method, which at least solves the problems of sensitivity to micro-cell parameters, easy generation of molding defects, and difficulty in achieving unsupported integration in the additive manufacturing process of hollow lattice components in the prior art.

[0006] This application provides a turbine rotor blade, comprising: The blade body has a first wall thickness and an internal cavity; and A lattice structure is filled in the internal cavity. The lattice structure includes multiple pillars, each pillar having a first diameter, and the angle between the pillars and the additive manufacturing plane satisfies the self-supporting molding tilt angle condition. The ratio of the first wall thickness to the first diameter is within a preset matching range, and the blade body and the lattice structure are integrally formed from a nickel-based high-temperature alloy.

[0007] Furthermore, the first wall thickness ranges from 1.0 mm to 1.5 mm, and the first diameter ranges from 0.5 mm to 1.2 mm.

[0008] Furthermore, the first wall thickness is 1.2 mm, and the first diameter is 1.0 mm.

[0009] Furthermore, the pre-screening matching range is from 1:1.2 to 1.5:0.5.

[0010] Furthermore, the lattice structure is a regular dodecahedral lattice structure.

[0011] Furthermore, the nickel-based superalloy is K477 nickel-based superalloy.

[0012] On the other hand, this application also provides a method for preparing a turbine rotor blade, the method being used to prepare the turbine rotor blade described above, the method comprising: Obtain the three-dimensional model data of the turbine rotor blade, the three-dimensional model data including the geometric information of the blade body and the lattice structure; Based on the three-dimensional model data, a selective laser melting process is used to print nickel-based high-temperature alloy powder into a supportless integrated shape to obtain a printed blade blank. The printed blade blank is subjected to hot isostatic pressing to obtain a densified blade; The densified blades are heat-treated to obtain the turbine rotor blades.

[0013] Furthermore, the parameters of the selected area laser melting process include: a layer thickness of 20 μm to 60 μm, a laser power of 120 W to 260 W, a scanning speed of 800 mm / s to 1200 mm / s, and a scanning spacing of 0.08 mm to 0.12 mm; and / or, The parameters for the hot isostatic pressing treatment include: a temperature of 1100℃ to 1190℃, a pressure of 150MPa to 180MPa, and a holding time of 3h to 5h.

[0014] Furthermore, the heat treatment includes solution treatment and aging treatment; and / or, The solution treatment is performed at a temperature of 1080℃ to 1120℃, with a holding time of 1.5h to 3h, using air cooling or oil cooling; and / or, The aging treatment temperature is 830℃ to 870℃, and the holding time is 3h to 6h.

[0015] Furthermore, in the step of using selective laser melting technology to perform unsupported integrated printing of high-temperature alloy powder, the scanning strategy of the selective laser melting technology is strip scanning or checkerboard scanning, and the interlayer rotation angle is 60° to 67°, and the oxygen content in the chamber is less than 100ppm.

[0016] This invention fundamentally solves the technical challenge of excessive sensitivity to micro-cell parameters in the additive manufacturing of hollow lattice components by establishing a preset matching relationship between the first wall thickness of the blade body and the first diameter of the lattice support, combined with self-supporting forming tilt angle conditions. This matching relationship optimizes the thermal conduction behavior at the thin-walled and lattice interface, enabling the component to maintain molten pool stability over a wide range of cell parameters, achieving true unsupported integrated forming and significantly reducing manufacturing complexity and post-processing costs. Simultaneously, through synergistically optimized selective laser melting process windows and hot isostatic pressing and heat treatment regimes, the density of the K477 nickel-based superalloy component reaches over 99.9%, with uniform and fine precipitation of the γ' strengthening phase. While ensuring a significant weight reduction of 30%–40%, the high-temperature creep life of the component is increased by more than 30% compared to the untreated state, meeting the dual requirements of lightweight and high reliability for aero-engine turbine rotor blades and improving the process maturity of additive manufacturing technology in the aero-engine field. Attached Figure Description

[0017] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention, and those skilled in the art can obtain other embodiments based on these drawings without creative effort.

[0018] Figure 1 is a structural diagram of a turbine rotor blade disclosed in an embodiment of the present invention, wherein (a) is a three-dimensional structural diagram of the turbine rotor blade, and (b) is a structural diagram of the turbine rotor blade after part of it has been cut off. Figure 2 This is a flowchart of the method for preparing turbine rotor blades disclosed in an embodiment of the present invention.

[0019] Explanation of reference numerals in the attached figures: 10. Blade body; 11. Internal cavity; 20. Lattice structure; 21. Support. Detailed Implementation

[0020] Embodiments of the present invention will now be described in more detail with reference to the accompanying drawings. While some embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the drawings and embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0021] Referring to Figure 1, this embodiment provides a turbine rotor blade, which includes a blade body 10 and a lattice structure 20. The blade body 10 has a first wall thickness and an internal cavity 11. Specifically, the blade body 10 constitutes the external aerodynamic profile and main load-bearing shell of the turbine rotor blade. Its first wall thickness refers to the thickness of the solid material in the direction perpendicular to the surface of the shell. This parameter directly determines the bending and torsional stiffness of the blade and the heat capacity characteristics during additive manufacturing. The internal cavity 11 is a closed or semi-closed space reserved inside the blade body 10 for lightweight design, providing a physical carrier for filling the lattice structure 20.

[0022] The lattice structure 20 fills the internal cavity 11. The lattice structure 20 includes multiple pillars 21, each pillar 21 having a first diameter, and the angle between the pillar 21 and the additive manufacturing forming plane satisfies the self-supporting forming tilt angle condition. In this embodiment, the lattice structure 20 is not a simple filler, but an internal reinforcing rib system that works in conjunction with the blade body 10. The first diameter refers to the characteristic dimension of the cross-section of the rod-shaped pillars 21 that constitute the lattice topology node. It should be understood that although Figure 1 schematically shows a specific lattice arrangement, under the technical concept of this invention, the specific topological form of the lattice structure 20 is not limited to that shown in Figure 1, as long as the spatial orientation of its pillars 21 can satisfy the aforementioned self-supporting forming tilt angle condition. The so-called self-supporting forming tilt angle condition refers to the geometric angle formed between the axis of the pillar 21 and the forming plane of the additive manufacturing layer by layer, so that during the laser melting process, the front edge of the currently solidifying molten pool can obtain sufficient self-supporting capacity by relying on the solidified solid structure below, thereby resisting gravity and molten pool surface tension without collapsing or excessive deformation without adding any additional auxiliary support structure. This self-supporting property, based on geometric principles, fundamentally eliminates the technical obstacle of removing supports in complex internal cavities.

[0023] In this invention, the ratio of the first wall thickness to the first diameter is within a preset matching range, and the blade body 10 and the lattice structure 20 are integrally formed from a nickel-based high-temperature alloy. This preset matching range is a key technical hub for achieving high-reliability supportless manufacturing in this invention. Specifically, in the selective laser melting process, the thermal response behavior of the thin-walled structure and the slender support 21 differs significantly: if the wall thickness is too thin or the support 21 is too thick, heat loss is likely to occur too quickly, resulting in incomplete fusion or cracks; conversely, if the wall thickness is too thick or the support 21 is too thin, local heat accumulation and molten pool instability are likely to occur. By controlling the ratio of the first wall thickness to the first diameter within the preset matching range, a dynamic balance mechanism for heat conduction between the thin wall and the lattice is essentially established on a macroscopic scale. This balance makes the forming process exhibit extremely strong robustness to microscopic parameters such as cell size and volume fraction, which are difficult to control precisely. Even if the microscopic parameters fluctuate within a certain range, as long as the macroscopic ratio meets the matching requirements, a stable molten pool morphology and good metallurgical bonding can still be maintained. Meanwhile, a nickel-based superalloy is used to integrally form the blade body 10 and the lattice structure 20, ensuring a continuous metallurgical bond at the interface. This avoids the assembly stress and weak connection areas caused by separate manufacturing, allowing the internal lattice to effectively share external loads and suppress thin-wall buckling. This embodiment, through the synergy of the aforementioned macroscopic dimensional matching and self-supporting geometry, constructs a supportless forming technology solution with a wide process window, laying the foundational concept for the subsequent optimization of specific parameters and topology.

[0024] In some embodiments, the first wall thickness ranges from 1.0 mm to 1.5 mm, such as 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, or 1.5 mm; the first diameter ranges from 0.5 mm to 1.2 mm, such as 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, or 1.2 mm. This numerical range is not arbitrarily chosen, but rather a result of a comprehensive trade-off between the thermophysical behavior and forming limits of nickel-based superalloys during selective laser melting. Specifically, when the first wall thickness is between 1.0 mm and 1.5 mm, the blade body 10 has sufficient heat capacity to buffer the instantaneous thermal shock from laser scanning, avoiding incomplete fusion defects caused by excessive heat dissipation, while also avoiding excessive residual stress and warping deformation risks due to excessive thickness. Simultaneously, a first diameter between 0.5 mm and 1.2 mm ensures that the support column 21 has sufficient rigidity to resist the surface tension of the molten pool without support, and its surface area to volume ratio facilitates rapid heat dissipation, preventing the thin rod from overheating and melting. Within this range, as a more preferred embodiment, the first wall thickness is 1.2 mm and the first diameter is 1.0 mm. This combination has been verified as the optimal solution for overall performance. Under this size ratio, the bending and torsional stiffness of the blade body 10 and the load-bearing efficiency of the lattice structure 20 achieve the best balance, and the internal thermal stress distribution of the printed component is the most uniform, resulting in minimal deformation during subsequent heat treatment.

[0025] To more precisely define the coupling relationship of the aforementioned dimensional parameters, the present invention further limits the preset matching range to 1:1.2 to 1.5:0.5. This ratio range constitutes a key process window for achieving high-quality unsupported molding, and its technical essence lies in maintaining the dynamic balance of thermal conduction between the thin-walled shell and the internal lattice pillars 21.

[0026] Furthermore, the lattice structure 20 is a dodecahedral lattice structure. The application of the dodecahedral topology in this invention is not merely for mechanical performance considerations, but more importantly, for its geometric characteristics and natural compatibility with additive manufacturing processes. Specifically, all the pillars 21 of the dodecahedral lattice have an angle of approximately 45° relative to the horizontal forming plane, an angle that perfectly matches the self-supporting forming tilt angle condition. During selective laser melting, the 45° tilt angle ensures that each newly molten metal droplet receives an effective support area of ​​more than 50% of the solidified entity below, guaranteeing the stability of the molten pool and avoiding powder adhesion or collapse caused by an excessively small overhang angle. This geometrically self-supporting characteristic allows the dodecahedral lattice to achieve high-precision forming without adding internal auxiliary supports, completely solving the industry pain point of difficult removal of supports for complex internal cavities. It should be understood that although this embodiment uses a regular dodecahedron as an example for detailed description, in other embodiments, any topological structure in which the inclination angle of the support 21 satisfies the self-support condition and can form a thermal equilibrium match with a specific wall thickness can be used as an alternative to the present invention.

[0027] Optionally, the nickel-based superalloy is K477 nickel-based superalloy. Specifically, both the blade body 10 and the lattice structure 20 are integrally formed from K477 nickel-based superalloy powder through selective laser melting. This alloy has excellent precipitation strengthening potential and high-temperature oxidation resistance, making it particularly suitable for the working conditions of low-pressure turbine rotor blades in aero-engines. However, for complex hollow lattice components manufactured by additive manufacturing, simply specifying the material grade is insufficient to guarantee the product's service reliability; its internal metallurgical quality is the key factor determining the final performance. Therefore, in this embodiment, the turbine rotor blade achieves a density of over 99.9% after hot isostatic pressing. This density index is the ratio of the solid material volume to the theoretical volume, measured by Archimedes' displacement method or metallographic quantitative analysis. It directly reflects the degree to which defects such as pores and cracks within the component are eliminated.

[0028] Furthermore, by ensuring complete healing of the pores at the interface between the support pillar 21 of the lattice structure 20 of the turbine rotor blade and the inner wall of the blade body 10 after hot isostatic pressing, residual micropores or incomplete fusion defects are less likely to occur. Simultaneously, the γ' reinforcing phase in the matrix structure is more uniform, achieving an ideal precipitation strengthening effect. It should be understood that this high-density state is not solely dependent on parameter adjustments in the hot isostatic pressing process, but rather a necessary result of the synergistic effect of the preset matching relationship between the first wall thickness and the first diameter in the aforementioned embodiments and the self-supporting molding angle condition of the support pillar 21. See [link to relevant documentation]. Figure 2 As shown, this embodiment also provides a method for fabricating turbine rotor blades, which constructs a complete manufacturing timeline from digital models to high-performance physical components. Specifically, the fabrication method includes the following steps: Step S100: Obtain the three-dimensional model data of the turbine rotor blade. The three-dimensional model data includes the geometric information of the blade body 10 and the lattice structure 20.

[0029] In this embodiment, the term "acquisition" is used to define the source status of the data, aiming to cover various passive reception scenarios such as receiving data from external designers, reading data from storage media, or transmitting data via a network. This avoids limiting the scope of protection to active design modeling activities, which is more in line with the industry reality of division of labor and cooperation between aero-engine designers and additive manufacturing suppliers. The three-dimensional model data not only defines the external aerodynamic profile of the blade, but more importantly, it contains the preset matching relationship between the first wall thickness of the blade body 10 and the first diameter of the support column 21 of the lattice structure 20, as well as the geometric topological information of the support column 21 to meet the self-supporting forming angle condition. This data constitutes the digital foundation for the subsequent supportless printing process, ensuring that the manufacturing end can accurately reproduce the heat conduction balance and self-supporting characteristics established by the design end, without requiring the manufacturing end to re-verify or adjust the micro-cell parameters.

[0030] Step S200: Based on the three-dimensional model data, the nickel-based high-temperature alloy powder is printed into a single, unsupported form using selective laser melting (SLM) technology to obtain a printed blade blank.

[0031] This step is the core execution link of the technical solution of this invention. "Unsupported" does not refer to a special setting of process parameters, but rather to the inevitable manifestation of the specific geometric matching relationship between the blade body 10 and the lattice structure 20 in the manufacturing process, as described in the previous embodiments. It is precisely because the ratio of the first wall thickness to the first diameter is within the preset matching range, and the support column 21 has a self-supporting forming angle, that the molten pool can obtain sufficient self-bearing capacity during solidification, thus physically eliminating the need for the addition of internal auxiliary support structures. This unsupported integrated printing method not only completely solves the industry problem of difficult or even impossible removal of complex internal cavity supports, but also avoids surface quality damage and residual stress concentration caused by support contact surfaces. Simultaneously, "integrated" emphasizes that the blade body 10 and the lattice structure 20 form a continuous whole through metallurgical bonding during the same printing process, ensuring the connection strength and load transfer efficiency of their interface. It should be understood that this step here only limits the process type and the key action feature of being unsupported; specific process parameters such as layer thickness, laser power, and scanning speed will be further detailed in subsequent embodiments.

[0032] Furthermore, the parameters of the selective laser melting process include: a layer thickness of 20μm to 60μm, such as 20μm, 30μm, 40μm, 50μm, or 60μm; a laser power of 120W to 160W, such as 120W, 130W, 140W, 150W, or 160W; a scanning speed of 800mm / s to 1200mm / s, such as 800mm / s, 900mm / s, 1000mm / s, or 1200mm / s; and a scanning spacing of 0.08mm to 0.12mm, such as 0.08mm, 0.1mm, or 0.12mm. This parameter range is not an isolated process selection, but rather a result of deep coupling with the preset matching relationship between the first wall thickness of the blade body 10 and the first diameter of the lattice structure 20. Within this parameter window, the energy density of the laser body is controlled within a balanced range that ensures the complete melting of the nickel-based superalloy powder and the formation of a stable molten pool, while preventing overheating that could lead to thin-wall burn-through or the melting of thin pillars.

[0033] In a preferred embodiment, the layer thickness is 30 μm, the laser power is 160 W, the scanning speed is 1000 mm / s, and the scanning spacing is 0.10 mm. Under this preferred parameter combination, the width-to-depth ratio of the molten pool is most conducive to achieving dense overlap between layers and channels, while the heat input is moderate, effectively reducing the residual stress level of the printed component. In the step of unsupported integrated printing of high-temperature alloy powder using selective laser melting (SLM), the scanning strategy of SLM is strip scanning or checkerboard scanning, and the interlayer rotation angle is 60° to 67°, such as 60°, 64°, and 67°, etc., with a chamber oxygen content below 100 ppm, such as 90 ppm. The choice of scanning strategy directly affects the thermal field distribution and microstructure uniformity inside the component.

[0034] Specifically, strip scanning involves dividing the forming surface into multiple strip-shaped regions approximately 10mm wide, with the laser scanning back and forth within each strip, moving to the next strip after completing one. Checkerboard scanning divides the forming surface into several square sub-regions, scanning them in a skip-step sequence. Regardless of the partitioning strategy used, the key is to maintain a rotation angle of 60° to 67° between adjacent printed layers. This specific interlayer rotation angle effectively disrupts the vector direction of heat accumulation, preventing excessive columnar crystal growth and anisotropy caused by continuous heat accumulation in a single direction, thereby significantly reducing the risk of thermal stress concentration at the connection between the blade body 10 and the lattice support 21. Simultaneously, for the chemically active K477 nickel-based superalloy, the oxygen content in the chamber is a critical environmental parameter for controlling metallurgical quality. Strictly controlling the oxygen content to below 100ppm (preferably below 50ppm) can suppress the formation of oxide films on the molten pool surface and the generation of internal oxide inclusions from the source, ensuring the purity and mechanical properties of the fine support 21 of the lattice structure 20. It should be understood that although this embodiment lists two specific forms, strip scanning and checkerboard scanning, in other embodiments, any partitioned scanning strategy that can achieve uniform thermal field dispersion and is matched with the corresponding interlayer rotation angle can be applied.

[0035] Step S300: The printed blade blank is subjected to hot isostatic pressing to obtain a dense blade.

[0036] The inherent rapid melting and solidification characteristics of selective laser melting inevitably introduce micron-sized pores or incomplete fusion defects into the printed blank. If these defects are not eliminated, they will become initiation points for fatigue cracks. Hot isostatic pressing (HIP) utilizes the creep mechanism under high temperature and high pressure to induce plastic flow in the material, closing internal pores, and is a necessary means to achieve high density in components. In this embodiment, this step ensures that the blade achieves a density ≥99.9%. After this step, the printed blade blank is transformed into a dense blade with effectively eliminated internal defects, laying a clean matrix foundation for subsequent mechanical property improvements.

[0037] In this step, the parameters for hot isostatic pressing (HIP) include: a temperature of 1100℃ to 1190℃, such as 1100℃, 1120℃, 1130℃, 1140℃, 1150℃, 1160℃, 1170℃, or 1190℃; a pressure of 150MPa to 180MPa, such as 150MPa, 160MPa, 170MPa, or 180MPa; and a holding time of 3h to 5h, such as 3h, 4h, or 5h. This step aims to eliminate micron-sized pores and microcracks that are unavoidable during selective laser melting (SLM). Under the synergistic effect of the above temperature and pressure, the nickel-based superalloy powder matrix undergoes high-temperature creep and plastic flow, causing the internal pores to gradually shrink until they are completely closed under the combined drive of mechanical pressure and surface tension. This temperature range is slightly below the solidus temperature of nickel-based superalloys, ensuring sufficient plastic deformation capacity for densification while avoiding damage to mechanical properties due to excessively high temperatures causing dissolution of primary carbides or abnormal grain growth. A pressure range of 150 MPa to 180 MPa provides the driving force needed to overcome the material's yield strength, ensuring effective healing even for minute pores deep within the lattice structure 20. The holding time of 3 to 5 hours is determined based on pore closure dynamics; too short a time may lead to insufficient densification in the central region, while too long a time increases production costs and may cause microstructure coarsening.

[0038] Step S400: The densified blades are heat-treated to obtain turbine rotor blades.

[0039] While hot isostatic pressing eliminates internal defects, it does not optimize the microstructure of the material. For nickel-based superalloys, their excellent high-temperature mechanical properties mainly depend on the size, morphology, and distribution of the γ' strengthening phase. This step, through a specific heat treatment regime, regulates the precipitation kinetics of the strengthening phase, ensuring its uniform and fine dispersion in the matrix, thereby endowing the blade with the creep resistance and service life required for final service.

[0040] Thus, through four closely linked steps—data acquisition, supportless printing, densification, and microstructure control—the entire process from raw data to high-performance turbine rotor blades has been completed. This method is not only logically rigorous, but each step is also adapted to address specific technical challenges in additive manufacturing of hollow lattice components, forming an inseparable and collaborative process system.

[0041] Furthermore, the heat treatment in this application includes solution treatment and aging treatment. This is a decisive step in imparting the final service performance of the turbine rotor blades. Specifically, the solution treatment temperature is between 1080°C and 1120°C, for example, 1080°C, 1100°C, or 1120°C, and the holding time is between 1.5h and 3h, for example, 1.5h, 3h, or 3h, using air cooling or oil cooling. This solution treatment aims to fully dissolve the coarse, segregated γ' strengthening phase in the cast or printed microstructure back into the matrix, while eliminating dendrite segregation and residual stress, obtaining a homogeneous supersaturated solid solution. The subsequent aging treatment temperature is between 830°C and 870°C, for example, 830°C, 850°C, or 870°C, and the holding time is between 3h and 6h, for example, 3h, 5h, or 6h. Within this temperature range, the γ' phase in the supersaturated solid solution recrystallizes again in a fine, dispersed, cubic morphology, with its size and volume fraction precisely controlled to achieve optimal strengthening. This two-step heat treatment process forms a tight technical loop with the aforementioned supportless printing and hot isostatic pressing (HIP) processes: supportless printing reduces surface damage and stress concentration sources caused by support removal, HIP eliminates internal defects, and precise heat treatment constructs an optimized strengthening phase structure on a pure and dense matrix. The synergistic effect of these three processes results in a creep rupture life of the final turbine rotor blade at 900℃ / 300MPa that is more than 30% higher than that of components not optimized by this synergistic process, fully demonstrating the innovative contribution of this synergistic process window to the manufacturing of high-performance aero-engine components.

[0042] The following will describe in detail the method for manufacturing turbine rotor blades according to specific embodiments: Example 1 Taking the low-pressure turbine rotor blade of a certain type of turboprop engine as an example, the following steps are implemented.

[0043] Step 1: Structural Design 3D modeling of the blade body: The outer contour is determined according to aerodynamic design requirements, the internal shell is hollow, and the wall thickness is set to 1.2mm.

[0044] Internal cavity definition: Define the area inside the blade that needs to be filled as a closed cavity, and output it in .stp or similar format.

[0045] Lattice filling: Based on the internal cavity geometry, a rhombic dodecahedron lattice structure was selected from its internal process library for filling. The diameter of the lattice support pillars was set to 1.0 mm.

[0046] Step 2: Material preparation and SLM printing K477 nickel-based high-temperature alloy powder was selected, with a particle size distribution of 15μm~53μm, a Hall flow rate ≤20s / 50g, and a loose packing density ≥4.2g / cm³.

[0047] Equipment: Industrial-grade SLM equipment (such as EOS290 or similar).

[0048] Parameters: layer thickness 30μm, laser power 160W, scanning speed 1000mm / s, scanning line distance 0.10mm.

[0049] Strategy: Strip scanning, strip width 10mm, interlayer rotation angle 67°, chamber oxygen content <50ppm. No internal support was used during printing.

[0050] Step 3: Post-processing Hot isostatic pressing: 1180℃×160MPa×4h, argon atmosphere.

[0051] Heat treatment: Solution treatment: 1100℃×2h, air cooling; Aging treatment: 850℃×4h, air cooling.

[0052] Testing and Verification Appearance and non-destructive testing: Visual and X-ray inspection was conducted. There were no cracks or warping, the lattice structure was intact, and it was well connected to the inner wall of the blade.

[0053] Weight reduction effect: The weighing results show a weight reduction of 36% to 38% compared to solid blades.

[0054] Example 2 Taking the low-pressure turbine rotor blade of a certain type of turboprop engine as an example, the following steps are implemented.

[0055] Step 1: Structural Design Blade 3D modeling: The outer contour is determined according to aerodynamic design requirements, the internal shell is hollow, and the wall thickness is set to 1.2mm.

[0056] Internal cavity definition: Define the area inside the blade that needs to be filled as a closed cavity, and output it in .stp or similar format.

[0057] Lattice filling: Based on the cavity geometry, a rhombic dodecahedron lattice structure was selected from its internal process library for filling. The diameter of the lattice support pillars was set to 1.0 mm.

[0058] Step 2: Material preparation and SLM printing K477 nickel-based high-temperature alloy powder was selected, with a particle size distribution of 15μm~53μm, a Hall flow rate ≤20s / 50g, and a loose packing density ≥4.2g / cm³.

[0059] Equipment: Industrial-grade SLM equipment (such as EOS290 or similar).

[0060] Parameters: layer thickness 30μm, laser power 160W, scanning speed 1000mm / s, scanning line distance 0.10mm.

[0061] Strategy: Strip scanning, strip width 10mm, interlayer rotation angle 67°, chamber oxygen content <50ppm. No internal support was used during printing.

[0062] Step 3: Post-processing Hot isostatic pressing: 1180℃×160MPa×4h, argon atmosphere.

[0063] Heat treatment: Solution treatment: 1100℃×2h, air cooling; Aging treatment: 850℃×4h, air cooling.

[0064] Testing and Verification Appearance and non-destructive testing: Visual and X-ray inspection revealed no cracks or warping, the lattice structure was intact, and it was well connected to the inner wall of the blade.

[0065] Weight reduction effect: The weighing results show a weight reduction of 36% to 38% compared to solid blades.

[0066] Example 3 Based on Example 1, only the diameter of the dot matrix support pillars was changed to verify the printability of the pillar diameter range:

[0067] As can be seen from the above embodiments, supportless printing can be achieved within the range of 0.8mm to 1.2mm in diameter of the support column, and the appropriate size can be selected according to the strength / rigidity requirements.

[0068] In actual installation tests and performance evaluations, the low-pressure turbine rotor blades manufactured using the technical solution of this invention exhibited significant advantages in lightweight design and improved mechanical properties. Specifically, through precise weighing measurements, the turbine rotor blades showed a weight reduction of 36% to 38% compared to traditional solid blades of the same size and material. This weight reduction not only directly reduced the overall mass of the rotor but also effectively reduced the centrifugal load and moment of inertia of the turbine disk, thereby improving the engine's thrust-to-weight ratio and dynamic response characteristics. It should be understood that this weight reduction falls within the 30% to 40% range expected in the aforementioned embodiments of this invention, demonstrating the effectiveness of the macroscopic dimensional matching design in achieving extreme lightweighting while ensuring structural rigidity.

[0069] In terms of high-temperature mechanical properties, the creep life of this turbine rotor blade is improved by more than 30% compared to the unoptimized component without size matching optimization and synergistic post-treatment. The microscopic mechanism of this performance leap lies in the fact that the preset wall thickness and support diameter matching relationship eliminates thermal mismatch defects during the printing process, and the hot isostatic pressing treatment achieves a density of more than 99.9%, completely eliminating fatigue crack initiation sources; at the same time, precise solution aging heat treatment promotes the precipitation of γ' strengthening phase with optimal size and distribution morphology, significantly enhancing the high-temperature creep resistance of the matrix. This fully demonstrates that the present invention is not a simple structural weight reduction, but rather achieves the dual guarantee of lightweight and high performance through the integrated synergistic design of "structure-process-microstructure".

[0070] Based on the above embodiments, it can be seen that the low-pressure turbine rotor blades of turboprop engines prepared using the technical solution of this invention can pass the additive manufacturing process maturity level 4 (TRL4+) verification. This means that the technical solution has surpassed the laboratory principle verification stage and has industrial applicability for engineering application and mass production in relevant aero-engine models. This embodiment, by grounding abstract technical features in specific commercial products and application scenarios, not only confirms the creative contribution of this invention in solving the manufacturing problem of hollow lattice components, but also provides solid factual evidence and data support for subsequent technology transfer and infringement damage calculation.

[0071] The above-described embodiments are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of protection. It should be noted that those skilled in the art can make various modifications and improvements without departing from the inventive concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A turbine rotor blade, characterized in that, include: The blade body (10) has a first wall thickness and the blade body (10) has an internal cavity (11). as well as A lattice structure (20) is filled in the internal cavity (11). The lattice structure (20) includes a plurality of pillars (21). The pillars (21) have a first diameter, and the angle between the pillars (21) and the additive manufacturing molding plane satisfies the self-supporting molding tilt angle condition. The ratio of the first wall thickness to the first diameter is within a preset matching range, and the blade body (10) and the lattice structure (20) are integrally formed from a nickel-based high-temperature alloy.

2. The turbine rotor blade according to claim 1, characterized in that, The first wall thickness ranges from 1.0 mm to 1.5 mm, and the first diameter ranges from 0.5 mm to 1.2 mm.

3. The turbine rotor blade according to claim 2, characterized in that, The first wall thickness is 1.2 mm, and the first diameter is 1.0 mm.

4. The turbine rotor blade according to claim 1, characterized in that, The pre-screening matching range is from 1:1.2 to 1.5:0.

5.

5. The turbine rotor blade according to claim 4, characterized in that, The lattice structure (20) is a regular dodecahedral lattice structure.

6. The turbine rotor blade according to claim 1, characterized in that, The nickel-based superalloy is K477 nickel-based superalloy.

7. A method for manufacturing turbine rotor blades, characterized in that, The method for preparing the turbine rotor blade is used to prepare the turbine rotor blade according to any one of claims 1 to 6, the method comprising: Obtain the three-dimensional model data of the turbine rotor blade, the three-dimensional model data including the geometric information of the blade body (10) and the lattice structure (20); Based on the three-dimensional model data, a selective laser melting process is used to print nickel-based high-temperature alloy powder into a supportless integrated shape to obtain a printed blade blank. The printed blade blank is subjected to hot isostatic pressing to obtain a densified blade; The densified blades are heat-treated to obtain the turbine rotor blades.

8. The preparation method according to claim 7, characterized in that, The parameters of the selected area laser melting process include: a layer thickness of 20 μm to 60 μm, a laser power of 120 W to 260 W, a scanning speed of 800 mm / s to 1200 mm / s, and a scanning spacing of 0.08 mm to 0.12 mm; and / or, The parameters for the hot isostatic pressing treatment include: a temperature of 1100℃ to 1190℃, a pressure of 150MPa to 180MPa, and a holding time of 3h to 5h.

9. The preparation method according to claim 8, characterized in that, The heat treatment includes solution treatment and aging treatment; and / or, The solution treatment is performed at a temperature of 1080℃ to 1120℃, with a holding time of 1.5h to 3h, using air cooling or oil cooling; and / or, The aging treatment temperature is 830℃ to 870℃, and the holding time is 3h to 6h.

10. The preparation method according to any one of claims 7 to 9, characterized in that, In the step of using selective laser melting technology to perform unsupported integrated printing of high-temperature alloy powder, the scanning strategy of the selective laser melting technology is strip scanning or checkerboard scanning, and the interlayer rotation angle is 60° to 67°, and the oxygen content in the chamber is less than 100ppm.

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