Preparation method and application of a dual-property powder turbine disc with gradient structure and performance

Abstract

The application belongs to the technical field of powder metallurgy, and relates to a preparation method and application of a dual-property powder turbine disc with gradient structure and performance. In the preparation of the dual-property powder turbine disc, first, superalloy powder is prepared, and pre-heat treatment is performed on the superalloy powder; second, the superalloy powder is screened, and then the superalloy powder of different particle size sections obtained after screening is subjected to selective screening of electrical properties; then, the superalloy powder with the same electrical properties and different particle size sections is mixed to obtain mixed powder with several different electrical properties; then, the mixed powder with several different electrical properties is loaded into corresponding regions in a jacket according to electrical properties, and after degassing and sealing welding treatment are performed on the jacket, hot isostatic pressing treatment is performed to obtain a blank; finally, heat treatment is performed on the blank to obtain the required dual-property powder turbine disc. The preparation method provides a preparation scheme with simple process, high degree of automatic control, short production cycle and lower cost for an aero-engine turbine disc.

Description

Technical Field

[0001] This invention belongs to the field of powder metallurgy technology, specifically relating to a method for preparing a dual-performance powder turbine disk with gradient structure and properties, and its application. Background Technology

[0002] With the increasing thrust-to-weight ratio of aero engines, the inlet temperature of advanced engine turbines can reach 1800℃, or even above 2000℃. Although equipped with cooling systems, the turbine disk still needs to withstand temperatures above 500℃. Nickel-based powder superalloys exhibit excellent mechanical and corrosion resistance properties under high-temperature conditions, making them the preferred material for key hot-end components such as advanced aero engine turbine disks. Aero engine turbine disks typically operate between 550℃ and 850℃, thus requiring materials with high temperature resistance and performance stability. The temperature load on aero engine turbine disks gradually decreases from the rim (disk edge) to the hub (disk center) (the gradient can reach 200℃), while the stress load gradually increases. Specifically, the hub (disc center) operates at low temperatures and is the direct bearer of turbine shaft torque, needing to withstand shear forces from the turbine main shaft and centrifugal forces from the turbine disk. Therefore, this region requires a fine-grained structure to ensure sufficient strength and fatigue resistance. Conversely, the rim (disc edge) operates at high temperatures (because it is closer to the high-temperature intake channel), primarily driving blade rotation. It needs to withstand localized torque separation transmitted from the spokes and centrifugal forces from the blades. Therefore, this region requires a coarse-grained structure to ensure sufficient durability, creep resistance, and resistance to fatigue crack propagation. Based on the differences in temperature and load experienced by different parts of the turbine disk under actual operating conditions, it is clear that aero-engine turbine disks need to obtain different grain sizes and microstructures in different regions to achieve corresponding temperature and load-bearing properties. This necessitates obtaining a new generation of turbine disks with a dual-grain structure and dual-performance or gradient microstructure / performance. Since the characteristics of dual-performance powder disks are consistent with the actual operating conditions of turbine disks, they can fully utilize the material's performance potential, making them the preferred solution for next-generation aero-engine turbine disks. To achieve a dual-structure, dual-performance powder turbine disk, the grain size of the hub (disk center) should be ASTM grade 8~12 (5.6μm~22.5μm), while the grain size of the rim (disk edge) should be approximately ASTM grade 3~6 (45μm~127μm).

[0003] However, the key challenge currently facing dual-performance powder turbine disks is determining the appropriate fabrication process to achieve both grain-like microstructure and dual properties. Currently, dual-performance powder turbine disks can be categorized into two types based on their structural characteristics: single-alloy dual-performance powder turbine disks and dual-alloy dual-performance powder turbine disks.

[0004] (1) Single alloy dual-performance powder turbine disks are produced by using a special method to achieve a dual-grain structure on a single alloy. This mainly involves hot isostatic pressing to prepare the billet, hot extrusion to form an ultrafine grain structure (approximately ASTM 10~13 grade), isothermal forging to form the disk blank, and then double (gradient) heat treatment to obtain microstructures and mechanical properties with different grain sizes in the hub (disk center) and rim (disk edge) regions. However, this method has problems such as long process flow, many control difficulties and high difficulty, long manufacturing cycle and high cost. The double (gradient) heat treatment process is adopted, that is, the temperature of the disk edge is higher than the γ′ dissolution temperature and the temperature of the disk center is lower than the γ′ dissolution temperature, so as to ensure that different grains are obtained in different locations. At the same time, this double heat treatment process requires the temperature difference between the rim and the hub to be more than 300℃, which requires a special heat treatment device and also has problems such as high process requirements, high complexity of manufacturing process, only one disk can be prepared at a time, high operation difficulty and high cost. Meanwhile, temperature differences across different parts of the turbine disk lead to variations in thermal expansion and deformation, generating internal thermal and structural stresses that are inherited as unstable residual stresses. These unstable residual stresses, combined with stresses incurred during service, reduce service safety. Another approach involves shortening the traditional dual-performance powder turbine disk manufacturing process by employing hot isostatic pressing (HIP) followed by selective thermomechanical treatment (STM). For example, General Electric uses STM to manufacture AF115 alloy dual-performance disks, where the disk core is forged to achieve a fine-grained structure, while the rim remains unforged and retains a coarse-grained structure under HIP. This method creates a "weak connection" in the mechanical properties of the forged and unforged parts, affecting the service safety of the turbine disk. Furthermore, under these conditions, the rim retains a HIP structure (the grain size of a conventional HIP structure is approximately ASTM 5-7), which cannot meet the grain size requirements (ASTM 3-6) for the rim of next-generation dual-performance turbine disks for aero-engines.

[0005] (2) Dual-performance turbine disks are prepared using dual alloys, which involves joining two different alloys together through special processing methods (such as superplastic forging, hot isostatic pressing, diffusion bonding, etc.). This technology requires both alloys to have good plasticity and be easy to process, and is suitable for manufacturing turbine disks with simple shapes. However, this type of turbine disk is prone to "weak bonding" in the joint area due to differences in the thermophysical properties and recrystallization characteristics of the alloys, which poses a potential risk for turbine disks used at high temperatures.

[0006] In view of this, the present invention proposes a method for preparing dual-performance powder turbine disks with gradient structure and properties to overcome the defects of the prior art and facilitate the preparation of a new generation of dual-performance turbine disks for aero engines with lower production costs, simpler production schemes and shorter production cycles. Summary of the Invention

[0007] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for preparing a dual-performance powder turbine disk with gradient structure and properties, as well as its application.

[0008] To achieve the above objectives, the present invention provides the following technical solution: On one hand, the present invention provides a method for preparing a dual-performance powder turbine disk with gradient structure and properties, comprising the following steps: Step 1: Prepare the required high-temperature alloy powder and pre-heat treat it; Step 2: The preheat-treated high-temperature alloy powder is sieved to obtain high-temperature alloy powders of different particle sizes. Step 3: Selective sieving of the high-temperature alloy powder for each particle size range was performed to obtain high-temperature alloy powder with different electrical properties for each particle size range. Step 4: Mix high-temperature alloy powders with the same electrical properties but different particle sizes to obtain several mixed powders with different electrical properties; Step 5: After loading the obtained mixed powders into the corresponding areas of the casing according to their electrical properties, the casing is degassed and sealed. Step 6: Perform hot isostatic pressing on the degassed and sealed cladding to obtain a hot isostatic pressing billet; Step 7: After removing the cladding from the hot isostatic pressed billet, perform standard heat treatment. After the standard heat treatment, a dual-performance powder turbine disk with the desired microstructure and property gradient is obtained.

[0009] Specifically, in step 1, primary high-temperature alloy powder is prepared by plasma rotating electrode method, and then the primary high-temperature alloy powder is subjected to sieving, electrostatic and magnetic separation to remove impurities, so as to obtain high-temperature alloy powder with the required particle size of 45μm~212μm.

[0010] Specifically, in step 1, the parameters for the preheating treatment are: temperature of 550℃~700℃, time of 8h~24h, and cooling method of furnace cooling.

[0011] Specifically, in step 2, the pre-heat-treated high-temperature alloy powder is finely sieved into multiple particle size ranges that can be selectively sieved based on electrical properties.

[0012] Furthermore, after the fine sieving, high-temperature alloy powders with multiple narrow particle size ranges are obtained. The ranges of the multiple narrow particle size ranges include: 45μm~53μm, 53μm~63μm excluding 53μm, 63μm~75μm excluding 63μm, 75μm~90μm excluding 75μm, 90μm~106μm excluding 90μm, 106μm~125μm excluding 106μm, 125μm~150μm excluding 125μm, 150μm~180μm excluding 150μm, and 180μm~212μm excluding 180μm. The appropriate range can be selected according to the actual situation, as long as the powder particle size can be distinguished and the powder particle size does not affect the screening of the powder's electrical properties.

[0013] Specifically, in step 3, when the high-temperature alloy powder is selectively sieved based on its electrical properties, the powder of each particle size range is sieved into three types: low conductivity powder / high resistivity powder, medium conductivity powder / medium resistivity powder, and high conductivity powder / low resistivity powder, based on the conductivity or resistivity of the high-temperature alloy powder.

[0014] Specifically, powders of each particle size range can be sieved into low conductivity powder, medium conductivity powder, and high conductivity powder, or high resistivity powder, medium resistivity powder, and low resistivity powder, or low conductivity powder, medium resistivity powder, and high conductivity powder; this can be determined according to the actual production situation. It should be noted that high-temperature alloy powders have high conductivity and low resistivity, and vice versa.

[0015] Specifically, in step 5, the low conductivity powder / high resistivity powder is loaded into the inner hub area of ​​the sleeve, the medium conductivity powder / medium resistivity powder is loaded into the inner spoke area of ​​the sleeve, and the high conductivity powder / low resistivity powder is loaded into the inner rim area of ​​the sleeve.

[0016] Specifically, in step 4, the particle size of each of the mixed powders is 45μm~212μm.

[0017] Specifically, in step 6, the hot isostatic pressing parameters are the existing process parameters of the selected high-temperature alloy.

[0018] Specifically, in step 7, the standard heat treatment is the existing standard heat treatment process parameters for the selected high-temperature alloy.

[0019] On the other hand, the present invention provides an application of a dual-performance powder turbine disk with gradient structure and properties in aero-engines, wherein the dual-performance powder turbine disk is prepared by the dual-performance powder turbine disk preparation method described above.

[0020] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects: 1. This invention eliminates internal thermal and structural stresses in high-temperature alloy powders through pre-heat treatment, achieving the preparation of stress-free or low-stress high-temperature alloy powders. During the preparation process, the high-temperature liquid metal rapidly forms spherical or near-spherical shapes under the action of surface tension, and then rapidly solidifies in the atomization chamber to form solid spherical powder; the spherical powder has a high solidification rate. The presence of incomplete precipitation of reinforcing phases and second phases leads to thermal and structural stresses within the high-temperature alloy powder. In the pre-heat treatment process of this invention, the high-temperature alloy powder spontaneously migrates to a low-energy stable state through atomic thermal activation motion, achieving stress relaxation and structural stabilization. Simultaneously, by selecting appropriate temperatures and times and designing a furnace cooling scheme, changes in the grain size within the high-temperature alloy powder are avoided. Ultimately, the pre-heat treatment eliminates thermal and structural stresses within the high-temperature alloy powder particles, resulting in powder particles with no or low residual stress, thus improving the accuracy of subsequent selective sieving based on electrical properties.

[0021] 2. This invention uses a wide particle size range of 45μm~212μm powder as raw material to improve material utilization and enhance powder filling and part shape control. Typically, powder metallurgy parts use narrow particle size ranges, such as 53μm~106μm or 53μm~150μm. It is generally believed that the closer the powder particle size, the closer the powder atomization mechanism (direct droplet formation mechanism, liquid line separation mechanism, or liquid film breakup mechanism) during atomization, and therefore, the more beneficial it is to the internal structure of the powder particles for the uniformity of the alloy's microstructure and subsequent mechanical properties. However, using powders with a narrow particle size range will result in the waste of powder outside the particle size range, increasing part manufacturing costs and the cost of subsequent reprocessing of "useless" powder. For example, the optimized process parameters for preparing powders with a particle size range of 53μm to 150μm result in a yield of approximately 75% to 80% for the 53μm to 150μm particle size range, while the proportion of powder with a wide particle size range of 45μm to 212μm can reach over 97%. Therefore, this invention uses powder with a wide particle size range of 45μm to 212μm as raw material, essentially achieving full utilization of the plasma rotating electrode powder and effectively reducing the raw material cost of dual-performance powder turbine disk components. Simultaneously, the fine powder in the wide particle size range can further and effectively fill the gaps between the coarse powders, improving the filling density and uniformity, which is beneficial for uniform shrinkage in the subsequent hot isostatic pressing process and improves the shape control effect of the manufactured parts.

[0022] 3. This invention utilizes the electrical properties of powder particles for screening, achieving fine sieving of powder particles with different grain sizes and grain boundary densities. In the preparation of high-temperature alloy powders, the high-temperature liquid metal originates from a small region of the original rod. Due to microscopic compositional segregation during solidification, slight differences in chemical composition occur between the liquid metal particles, affecting the solidification behavior of the droplets (such as supercooling and nucleation rate). Furthermore, fluctuations in the chemical composition of the micro-regions within the droplets lead to local liquidus temperature changes and localized supercooling, providing a high driving force for supercooling. These compositional fluctuations create energy and structural fluctuations, reduce interfacial energy, and lower the local nucleation energy barrier, making the areas with compositional fluctuations preferential nucleation sites. Under the combined effect of a higher driving force for supercooling and more potential nucleation sites, the nucleation rate is increased, promoting powder solidification. Additionally, high-melting-point substances such as non-uniformly distributed MC-type carbides (TiC, NbC, etc.) provide heterogeneous nucleation sites, promoting nucleation. In summary, due to factors such as differences in micro-region composition, fluctuations in chemical composition, and heterogeneous nucleation of non-uniformly distributed high-melting-point materials, the solidified high-temperature alloy powder possesses different grain sizes. When the particle sizes of high-temperature alloy powders are similar, the grain size or grain boundary density within the particles becomes the main factor affecting the electrical properties of the powder. Therefore, this invention selects high-temperature alloy powders with narrow particle size distributions for electrical property sieving. Because the atomic arrangement at grain boundaries is irregular and microscopic distortion regions exist, when moving electrons encounter grain boundaries, their direction of motion changes (i.e., they are scattered), thus hindering the directional movement of electrons, macroscopically manifested as a decrease in conductivity / an increase in resistivity. Therefore, by utilizing the "grain boundary scattering mechanism" and selective sieving based on electrical properties, the identification and sieving of grain size / grain boundary density within high-temperature alloy powder particles of similar sizes can be achieved.

[0023] 4. This invention, based on the inherent characteristics of high-temperature alloy powder, optimizes the correlation between grain size and powder loading area within the powder, achieving a simple and short-process fabrication of dual-performance powder turbine disks. Traditional fabrication processes for dual-performance powder high-temperature alloy turbine disks require steps such as hot isostatic pressing (HIP), hot extrusion, isothermal forging, and dual heat treatment to regulate microstructure. These processes are lengthy, difficult to control, have long production cycles, and are costly. Furthermore, hot extrusion, isothermal forging, and dual heat treatment processes are difficult to control under current technology, involve numerous influencing factors, have low automation, and result in poor batch stability. This invention, after optimizing powder size and powder loading area, allows for the direct fabrication of dual-performance powder turbine disks using HIP and conventional heat treatment. The process is simple, has fewer control points, and the HIP and heat treatment processes are highly automated, which helps ensure batch stability.

[0024] In summary, this invention optimizes the existing dual-performance powder turbine disk manufacturing process, specifically addressing the technical challenges of numerous and difficult control points and local "weak connections" in the existing process. Based on further optimizing the correlation between powder particle size and the service requirements of powder turbine disk components, this invention provides a manufacturing solution for aero-engine turbine disks that features a simple manufacturing process, high degree of automation, significantly shortened production cycle, and lower cost. Attached Figure Description

[0025] The accompanying drawings are incorporated in and form part of this specification, and together with the description serve to explain the principles of the invention.

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a flowchart of the preparation method of the present invention; Figure 2 This is the initial microstructure of the high-temperature alloy powder prepared in step 1 of Example 1 of the present invention; Figure 3 This diagram illustrates the fine sieving, electrical property (conductivity) screening, and mixing process of high-temperature alloy powder in the preparation method of this invention. Detailed Implementation

[0028] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. The embodiments described below do not represent all embodiments consistent with the present invention. Rather, they are merely examples consistent with some aspects of the invention as detailed in the appended claims.

[0029] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0030] See Figure 1 , 3 As shown, this invention provides a method for preparing a dual-performance powder turbine disk with gradient structure and properties, comprising the following steps: Step 1: Prepare the required high-temperature alloy powder and pre-heat treat it; Step 2: The preheat-treated high-temperature alloy powder is sieved to obtain high-temperature alloy powders of different particle sizes. Step 3: Selective sieving of the high-temperature alloy powder for each particle size range was performed to obtain high-temperature alloy powder with different electrical properties for each particle size range. Step 4: Mix high-temperature alloy powders with the same electrical properties but different particle sizes to obtain several mixed powders with different electrical properties; Step 5: After loading the obtained mixed powders into the corresponding areas of the casing according to their electrical properties, the casing is degassed and sealed. Step 6: Perform hot isostatic pressing on the degassed and sealed cladding to obtain a hot isostatic pressing billet; Step 7: After removing the cladding from the hot isostatic pressed billet, perform standard heat treatment. After the standard heat treatment, a dual-performance powder turbine disk with the desired microstructure and property gradient is obtained.

[0031] Specifically, in step 1, primary high-temperature alloy powder is prepared by plasma rotating electrode method, and then the primary high-temperature alloy powder is subjected to sieving, electrostatic and magnetic separation to remove impurities, so as to obtain high-temperature alloy powder with the required particle size of 45μm~212μm.

[0032] Specifically, in step 1, the parameters for the preheating treatment are: temperature of 550℃~700℃, time of 8h~24h, and cooling method of furnace cooling.

[0033] Specifically, in step 2, the pre-heat-treated high-temperature alloy powder is finely sieved into multiple particle size ranges that can be selectively sieved based on electrical properties.

[0034] Furthermore, after the fine sieving, high-temperature alloy powders with multiple narrow particle size ranges are obtained. The ranges of the narrow particle size ranges include: 45μm~53μm, 53μm~63μm excluding 53μm, 63μm~75μm excluding 63μm, 75μm~90μm excluding 75μm, 90μm~106μm excluding 90μm, 106μm~125μm excluding 106μm, 125μm~150μm excluding 125μm, 150μm~180μm excluding 150μm, and 180μm~212μm excluding 180μm. The appropriate range can be selected according to the actual situation, as long as the powder particle size can be distinguished and the powder particle size does not affect the screening of the powder's electrical properties.

[0035] Specifically, in step 3, when the high-temperature alloy powder is selectively sieved based on its electrical properties, the powder of each particle size range is sieved into three types: low conductivity powder / high resistivity powder, medium conductivity powder / medium resistivity powder, and high conductivity powder / low resistivity powder, based on the conductivity or resistivity of the high-temperature alloy powder.

[0036] Specifically, in step 5, the low conductivity powder / high resistivity powder is loaded into the inner hub area of ​​the sleeve, the medium conductivity powder / medium resistivity powder is loaded into the inner spoke area of ​​the sleeve, and the high conductivity powder / low resistivity powder is loaded into the inner rim area of ​​the sleeve.

[0037] Specifically, in step 4, the particle size of each of the mixed powders is 45μm~212μm.

[0038] Specifically, in step 6, the hot isostatic pressing parameters are the existing process parameters of the selected high-temperature alloy.

[0039] Specifically, in step 7, the standard heat treatment is the existing standard heat treatment process parameters for the selected high-temperature alloy.

[0040] This invention provides an application of a dual-performance powder turbine disk with gradient structure and properties in aero-engines. The dual-performance powder turbine disk is prepared using the dual-performance powder turbine disk preparation method described above.

[0041] To demonstrate the effectiveness of this invention, the following embodiments are provided for verification. Example 1

[0042] This embodiment provides a method for preparing a dual-performance powder turbine disk with gradient structure and properties. The specific steps are as follows: Step 1: Primary FGH4097 alloy powder was prepared by plasma rotating electrode method. After sieving, electrostatic and magnetic separation to remove impurities, FGH4097 alloy powder with a particle size range of 45μm~212μm was obtained.

[0043] Step 2: Perform preheating treatment on the processed FGH4097 alloy powder; specific process parameters: preheating temperature is 550℃, holding time is 24h, and cooling is carried out with the furnace.

[0044] Step 3: Finely sieve the cooled FGH4097 alloy powder to form FGH4097 alloy powder with different particle size ranges; specifically, the finely sieved particle size ranges are: 45μm~53μm, 53μm~75μm excluding 53μm, 75μm~90μm excluding 75μm, 90μm~125μm excluding 90μm, 125μm~150μm excluding 125μm, 150μm~180μm excluding 150μm, and 180μm~212μm excluding 180μm.

[0045] Step 4: Perform selective sieving of FGH4097 alloy powder of each particle size range after fine sieving; the specific sieving voltage is 32V, and FGH4097 alloy powder of each particle size range is sieved into low conductivity powder, medium conductivity powder and high conductivity powder.

[0046] Step 5: After sieving the FGH4097 alloy powder according to its electrical properties, mix the FGH4097 alloy powders with the same electrical properties but different particle size ranges to form low conductivity mixed powder, medium conductivity mixed powder and high conductivity mixed powder. The particle size of the three mixed powders is 45μm~212μm.

[0047] Step 6: The low conductivity mixed powder is loaded into the inner hub area of ​​the sleeve, the medium conductivity mixed powder is loaded into the inner spoke area of ​​the sleeve, and the high conductivity mixed powder is loaded into the inner rim area of ​​the sleeve. After filling, degassing and sealing are performed.

[0048] Step 7: The degassed and sealed cladding is subjected to hot isostatic pressing to obtain a hot isostatic pressing billet; the actual hot isostatic pressing temperature is 1200℃, the pressure is 150MPa, the time is 2h, and it is cooled with the furnace.

[0049] Step 8: After removing the cladding from the hot isostatic pressed billet, perform standard heat treatment. After the standard heat treatment, obtain the FGH4097 alloy dual-performance powder turbine disk with gradient changes in microstructure and properties.

[0050] Figure 2 Microstructure characterization of FGH4097 high-temperature alloy powder with a particle size of 45 μm to 212 μm prepared in step 1; from Figure 2 It can be seen that there is no correlation between the internal grain size of the powder particles and the powder particle size itself; that is, powder particles of similar size contain different grain sizes, and the difference is significant. Example 2

[0051] This embodiment provides a method for preparing a dual-performance powder turbine disk with gradient structure and properties. The specific steps are as follows: Step 1: Primary GH4720Li alloy powder was prepared by plasma rotating electrode method. After sieving, electrostatic and magnetic separation to remove impurities, GH4720Li alloy powder with a particle size range of 45μm~212μm was obtained.

[0052] Step 2: Perform preheating treatment on the treated GH4720Li alloy powder; specific process parameters: preheating temperature is 700℃, holding time is 8h, and cooling is carried out with the furnace.

[0053] Step 3: Finely sieve the cooled GH4720Li alloy powder to form alloy powders of different particle sizes. Specifically, the finely sieved particle sizes are: 45μm~53μm, 53μm~63μm excluding 53μm, 63μm~75μm excluding 63μm, 75μm~90μm excluding 75μm, 90μm~106μm excluding 90μm, 106μm~125μm excluding 106μm, 125μm~150μm excluding 125μm, 150μm~180μm excluding 150μm, and 180μm~212μm excluding 180μm.

[0054] Step 4: Perform selective sieving of the GH4720Li alloy powder of each particle size range after fine sieving; the specific sieving voltage is 30V, and the GH4720Li alloy powder of each particle size range is sieved into low conductivity powder, medium conductivity powder and high conductivity powder.

[0055] Step 5: After sieving the GH4720Li alloy powder according to its electrical properties, mix the GH4720Li alloy powders with the same electrical properties but different particle size ranges to form low conductivity mixed powder, medium conductivity mixed powder and high conductivity mixed powder. The particle size of the three mixed powders is 45μm~212μm.

[0056] Step 6: The low conductivity mixed powder is loaded into the inner hub area of ​​the sleeve, the medium conductivity mixed powder is loaded into the inner spoke area of ​​the sleeve, and the high conductivity mixed powder is loaded into the inner rim area of ​​the sleeve. After filling, degassing and sealing are performed.

[0057] Step 7: The degassed and sealed cladding is subjected to hot isostatic pressing to obtain a hot isostatic pressing billet; the actual hot isostatic pressing temperature is 1180℃, the pressure is 140MPa, the time is 3h, and it is cooled with the furnace.

[0058] Step 8: After removing the cladding from the hot isostatic pressed billet, perform standard heat treatment. After the standard heat treatment, a GH4720Li alloy dual-performance powder turbine disk with gradient changes in microstructure and properties is obtained. Example 3

[0059] This embodiment provides a method for preparing a dual-performance powder turbine disk with gradient structure and properties. The specific steps are as follows: Step 1: Primary EP962NP alloy powder was prepared by plasma rotating electrode method. After sieving, electrostatic and magnetic separation to remove impurities, EP962NP alloy powder with a particle size range of 45μm~212μm was obtained.

[0060] Step 2: Perform preheating treatment on the treated EP962NP alloy powder; specific process parameters: preheating temperature is 625℃, holding time is 18h, and cooling is carried out with the furnace.

[0061] Step 3: Finely sieve the cooled EP962NP alloy powder to form EP962NP alloy powder of different particle size ranges; specifically, the finely sieved particle size ranges are: 45μm~53μm, 53μm~63μm excluding 53μm, 63μm~90μm excluding 63μm, 90μm~106μm excluding 90μm, 106μm~150μm excluding 106μm, 150μm~180μm excluding 150μm, and 180μm~212μm excluding 180μm.

[0062] Step 4: Perform selective sieving of the EP962NP alloy powder of each particle size range after fine sieving; the specific sieving voltage is 28V, and the EP962NP alloy powder of each particle size range is sieved into low conductivity powder, medium conductivity powder and high conductivity powder.

[0063] Step 5: After sieving the EP962NP alloy powder according to its electrical properties, mix the EP962NP alloy powders with the same electrical properties but different particle size ranges to form low conductivity mixed powder, medium conductivity mixed powder and high conductivity mixed powder. The particle size of the three mixed powders is 45μm~212μm.

[0064] Step 6: The low conductivity mixed powder is loaded into the inner hub area of ​​the sleeve, the medium conductivity mixed powder is loaded into the inner spoke area of ​​the sleeve, and the high conductivity mixed powder is loaded into the inner rim area of ​​the sleeve. After filling, degassing and sealing are performed.

[0065] Step 7: The degassed and sealed cladding is subjected to hot isostatic pressing to obtain a hot isostatic pressing billet; the actual hot isostatic pressing temperature is 1215℃, the pressure is 160MPa, the time is 4h, and it is cooled with the furnace.

[0066] Step 8: After removing the cladding from the hot isostatic pressed billet, perform standard heat treatment. After the standard heat treatment, obtain the EP962NP alloy dual-performance powder turbine disk with gradient changes in microstructure and properties. Comparative Example

[0067] The difference between this comparative example and Example 1 is that the comparative example only uses the sieving method in step 1 and does not perform the operations in steps 2-5. In step 6, the FGH4097 alloy powder obtained in step 1 is loaded into the corresponding areas of the inner hub (disc center), spokes (spokes), and rim (disc rim) of the casing and then processed to finally obtain the FGH4097 alloy turbine disk.

[0068] In addition, the inventors conducted microstructure and performance tests on the dual-performance powder turbine disk prepared in the embodiments of the present invention and the turbine disk prepared in the comparative example. The specific test results are shown in Table 1 and Table 2 below.

[0069] Table 1. Grain size grade of turbine disk and room temperature tensile properties in the examples and comparative examples.

[0070] Table 2. High-temperature creep and low-cycle fatigue performance of turbine disks in the examples and comparative examples.

[0071] As shown in Tables 1 and 2, the dual-performance powder turbine disk prepared by this invention, when compared with the test results of the turbine disk prepared in the comparative example, exhibits a gradual transition from the hub (disk center) to the rim (disk edge) region, with increasingly smaller grain sizes. Furthermore, the hub (disk center) region demonstrates excellent strength and fatigue life, while the rim (disk edge) region exhibits excellent high-temperature creep life. Moreover, the performance of the spokes (spokes) region falls between that of the hub (disk center) and the rim (disk edge), achieving a gradient change in the mechanical properties of the turbine disk. Therefore, the dual-performance powder turbine disk prepared using the method of this invention can better meet the differentiated application requirements of turbine disks for aero-engines under actual operating conditions, considering the varying temperatures and loads they withstand.

[0072] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention.

[0073] It should be understood that the present invention is not limited to the content already described above, and various modifications and changes can be made without departing from its scope. The scope of the present invention is limited only by the appended claims.

Claims

1. A method for preparing a dual-performance powder turbine disk with gradient structure and properties, characterized in that, Includes the following steps: Step 1: Prepare the required high-temperature alloy powder and pre-heat treat it; the parameters of the pre-heat treatment are: temperature of 550℃~700℃, time of 8h~24h, and cooling method is furnace cooling; the particle size of the high-temperature alloy powder is 45μm~212μm. Step 2: The preheat-treated high-temperature alloy powder is sieved to obtain high-temperature alloy powders of different particle sizes. Step 3: Selective sieving of the high-temperature alloy powder for each particle size range was performed to obtain high-temperature alloy powder with different electrical properties for each particle size range. When the high-temperature alloy powder is selectively sieved based on its electrical properties, the powder of each particle size range is sieved into low-conductivity powder / high-resistivity powder, medium-conductivity powder / medium-resistivity powder, and high-conductivity powder / low-resistivity powder by utilizing the electrical conductivity or resistivity of the high-temperature alloy powder. Step 4: Mix high-temperature alloy powders with the same electrical properties but different particle sizes to obtain several mixed powders with different electrical properties; Step 5: After loading the obtained mixed powders into the corresponding areas of the casing according to their electrical properties, the casing is degassed and sealed. Step 6: Perform hot isostatic pressing on the degassed and sealed cladding to obtain a hot isostatic pressing billet; Step 7: After removing the cladding from the hot isostatic pressed billet, perform standard heat treatment to obtain a dual-performance powder turbine disk with the desired microstructure and property gradient.

2. The method for preparing a dual-performance powder turbine disk according to claim 1, characterized in that, In step 1, primary high-temperature alloy powder is first prepared using the plasma rotating electrode method, and then the primary high-temperature alloy powder is subjected to sieving, electrostatic and magnetic separation to remove impurities in sequence to obtain the desired high-temperature alloy powder.

3. The method for preparing a dual-performance powder turbine disk according to claim 1, characterized in that, In step 2, the pre-heat-treated high-temperature alloy powder is finely sieved into multiple particle size ranges that can be selectively sieved based on electrical properties.

4. The method for preparing a dual-performance powder turbine disk according to claim 3, characterized in that, After the fine sieving, high-temperature alloy powder with multiple narrow particle size ranges is obtained. The ranges of the multiple narrow particle size ranges include: 45μm~53μm, 53μm~63μm excluding 53μm, 63μm~75μm excluding 63μm, 75μm~90μm excluding 75μm, 90μm~106μm excluding 90μm, 106μm~125μm excluding 106μm, 125μm~150μm excluding 125μm, 150μm~180μm excluding 150μm, and 180μm~212μm excluding 180μm.

5. The method for preparing a dual-performance powder turbine disk according to claim 1, characterized in that, In step 5, the low conductivity powder / high resistivity powder is loaded into the inner hub area of ​​the sleeve, the medium conductivity powder / medium resistivity powder is loaded into the inner spoke area of ​​the sleeve, and the high conductivity powder / low resistivity powder is loaded into the inner rim area of ​​the sleeve.

6. The method for preparing a dual-performance powder turbine disk according to claim 1, characterized in that, In step 4, the particle size of each of the mixed powders is 45μm~212μm.

7. The application of a dual-performance powder turbine disk with gradient structure and properties in aero-engines, characterized in that, The dual-performance powder turbine disk is prepared using the dual-performance powder turbine disk preparation method as described in any one of claims 1 to 6.

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