Machining method and device for hub / bladed disc heterogeneous material alloy structural part

Abstract

The invention provides a machining method and device for a hub / bladed disc heterogeneous material alloy structural part. According to the method, diffusion welding is adopted for machining. The device comprises a central column of a circular truncated cone structure, and an outer ferrule is coaxially arranged outside the central column; a limiting ring is installed at the large axial end of the center column, and a gasket is arranged below the small axial end of the center column. The process conditions of diffusion welding comprise that in a vacuum environment, pressure of 6-7 t is applied at the temperature of 860-880 DEG C, and heat preservation is conducted for 90-110 min. When the method is adopted for machining the hub / bladed disc heterogeneous material alloy structural part, it can be guaranteed that vertical welding seams are evenly pressed, then a low-pressure area is sufficiently welded, interface holes are not prone to being formed, strength connection of the joint is improved, and it is guaranteed that the hub / bladed disc heterogeneous material alloy structural part can be applied in a long-service-life and high-strength mode; and meanwhile, the deformation of a high-pressure area is reduced, and local size out-of-tolerance of the part is avoided.

Description

Technical Field

[0001] The present invention belongs to the technical field of heterogeneous alloy welding, relates to the processing of a dual-alloy impeller of an aero-engine, and specifically relates to a method and device for processing a hub / blade heterogeneous material alloy structural part. Background Art

[0002] Aircraft engine compressor impellers and blades require a dual-alloy structure with different materials inside and outside due to significant stress and temperature gradients between the center and edge. During service, impellers are subjected to high temperatures, high pressures, extreme centrifugal forces, vibration, and combined mechanical, aerodynamic, and thermal loads. They also face the risk of corrosion and wear from oxidation, sulfidation, and particle erosion. This complex and dynamic operating environment requires comprehensive consideration of the coupled effects of multiple factors during design, manufacturing, and maintenance to ensure stable and reliable structural performance.

[0003] Diffusion welding, a precision solid-phase joining technology, has become a key process in the manufacture of complex internal cavity components such as hollow blades in aircraft engines due to its low deformation and high strength characteristics. This technology achieves metallurgical bonding through atomic diffusion, overcoming the significant deformation and low bond strength associated with traditional fusion welding processes, effectively meeting the manufacturing requirements of high-precision, long-life equipment.

[0004] For the manufacturing of regular, simple parts with a flat pressurized structure, diffusion welding technology not only simplifies the overall process and fixture design, but also makes it easy to ensure the uniformity of welding pressure and welding deformation. However, when faced with more complex heterogeneous alloy structures, the following difficulties arise:

[0005] First, although titanium alloys are not prone to the formation of oxide films and oxides at the weld interface due to their excellent oxygen dissolution properties, if the welding parameters are not appropriate, residual porosity defects at the interface are still difficult to completely eliminate. These microporous defects can significantly reduce the load-bearing capacity and crack resistance of the joint.

[0006] Second, due to the vertical welds in the structural parts, pressurization becomes difficult, and uneven pressure distribution at different positions of the vertical welds is likely to occur: the low-pressure area causes insufficient plastic deformation of the interface, resulting in insufficient welding rate in this area and the formation of interface holes, while locally excessively high interface pressure will increase the plastic deformation of this area, causing local dimensional deviations of the parts. Summary of the Invention

[0007] Aiming at the deficiencies existing in the prior art, the purpose of the present invention is to provide a processing method and device for a hub / disk heterogeneous material alloy structural member, so as to solve the technical problems that when the diffusion welding technology is used to process complex heterogeneous material alloy structural members in the prior art, the welding parameters are not appropriate and the interfacial residual pore defects are still difficult to completely eliminate; and the vertical welds are prone to uneven pressure, which in turn leads to insufficient welding in the low-pressure area and easy formation of interfacial pores, and the plastic deformation amount in the high-pressure area increases.

[0008] In order to solve the above technical problems, the present invention is implemented by adopting the following technical solutions:

[0009] A processing method for a hub / disk heterogeneous material alloy structural member, which is processed by diffusion welding, and radial and axial limits are applied to the hub and the disk during processing.

[0010] The process conditions of the diffusion welding are as follows: in a vacuum environment with a vacuum degree less than or equal to 5×10 -3 Pa, the temperature is raised to the welding temperature at a heating rate of 5-15°C / min, and then a pressure of 6t-7t is applied at a temperature of 860-880°C and held for 90-110 min.

[0011] Preferably, a pressure of 6t is applied at a temperature of 860°C and held for 90 min; or a pressure of 6t is applied at a temperature of 880°C and held for 90 min; or a pressure of 7t is applied at a temperature of 860°C and held for 90 min; or a pressure of 6t is applied at a temperature of 860°C and held for 110 min.

[0012] The present invention also has the following technical features:

[0013] Specifically, the hub is made of titanium alloy.

[0014] Specifically, the disk is made of nickel-based alloy, preferably a high-temperature nickel-based alloy with a bias towards medium and low temperatures but higher strength, and most preferably Inconel 625 alloy.

[0015] Specifically, computer simulation is used to design the welding temperature, welding pressure and welding time of the diffusion welding.

[0016] Specifically, the welding temperature design includes: based on the characteristic temperature points for the materials of the hub and the disk, designing and conducting diffusion welding experiments at different welding temperatures to obtain the influence law of the welding temperature on the microstructure and structure of the materials; through thermodynamic simulation software, establishing the thermodynamic criteria and laws for the formation of joints at different welding temperatures, obtaining the influence law of the welding temperature on the diffusion welding forming of the materials of the hub and the disk, and finally determining the welding temperature range.

[0017] Specifically, the welding pressure design includes: within the welding temperature range, thermal simulation compression experiments are conducted to obtain the strain-time curves of various materials, and corresponding creep constitutive equations are established; a diffusion welding interface hole closure model is constructed, and then a finite element simulation method is used to carry out the simulation of the diffusion welding process with vertical weld pressurization. The creep constitutive equation is incorporated into the diffusion welding interface hole closure model to study the deformation law of specimens under different process parameter combinations, and finally the welding pressure range is determined.

[0018] Specifically and preferably, the creep constitutive equation is as shown in Equation Ⅰ below:

[0019]

[0020] In the formula:

[0021] represents the creep strain rate of the material.

[0022] σ represents the nominal stress.

[0023] t represents the creep time.

[0024] m represents the material constant in the first stage of creep.

[0025] n represents the creep exponent.

[0026] C represents the material constant.

[0027] Specifically, the welding time design includes: using the finite element simulation method to simulate the process of bonding at the heterogeneous alloy interface; based on the diffusion welding of heterogeneous alloys with vertical weld pressurization, an initial interface micropore geometry model is established; based on the creep constitutive equations of various materials, the influence laws of welding temperature, welding pressure, welding time, and surface roughness on the closure of interface micropores are studied, and the evolution law of the interface micropore size over time is obtained, and finally the welding time range is determined.

[0028] Specifically, the processing method includes the following steps:

[0029] Step 1, rough machining: According to the designed dimensions of the blisk and the hub, the material is forged and cut to obtain the blanks of the blisk and the hub; the blanks of the blisk and the hub are clamped on the processing equipment and clamped and positioned; then the blanks are turned.

[0030] Step 2, finish machining: According to the shapes and dimensions of the hub and the blisk after rough machining, trimming and semi-finishing are carried out to make the dimensions of the parts reach the final dimensions; the mating surfaces of the hub and the blisk are finish machined to ensure the surface finish and roughness, and the roughness is Ra 1.6μm.

[0031] Step 3, Inspection and Assembly: Inspect the hub and disk after precision machining to ensure that their quality meets the design requirements; then finely assemble the hub and disk, and clean and perform anti-rust treatment on the assembled disk.

[0032] Step 4, Diffusion Welding: Apply Keller reagent to the surfaces of the hub and disk for surface activation. After drying, assemble the hub and disk to obtain a structural member; spray a welding-resistant agent on the surfaces of the vertical weld auxiliary pressure device and the structural member, and finally install the vertical weld auxiliary pressure device on the structural member; then place the assembled vertical weld auxiliary pressure device and the structural member in a diffusion furnace, close the furnace door, evacuate the air, and perform welding under set conditions. After welding is completed, turn off the heating power supply, cool the furnace to room temperature, and take out the hub / disk heterogeneous material alloy structural member.

[0033] The present invention also protects a vertical weld auxiliary pressure device for implementing the processing method of the hub / disk heterogeneous material alloy structural member as described above, which is used for radially and axially limiting the hub and disk.

[0034] Specifically, the vertical weld auxiliary pressure device includes an outer ring, a limiting ring, a washer, and a central column with a frustum structure; the central hole of the hub is sleeved on the central column, and the disk is assembled on the outside of the hub; the outer ring is sleeved on the outside of the disk; the limiting ring is sleeved on the outside of the large end of the central column and is in close contact with the upper end face of the hub, and washers are provided on the lower end faces of the hub and the disk.

[0035] Specifically, the inclination angle of the central column is 80° to 120°, and the preferred inclination angle is 100°. The inclination angle of the central column is exactly the same as that of the central hole of the hub.

[0036] Specifically, the central column is made of a nickel-based alloy, preferably a high-temperature nickel-based alloy, and most preferably a high-temperature alloy that is biased towards medium and low temperatures but has higher strength, such as one or more of Inconel625 alloy, GH4169 alloy, Haynes282 alloy, and GH4090 alloy.

[0037] Specifically, the outer ring, the limiting ring, and the washer are made of graphite.

[0038] Specifically, the inclination angle of the central column is designed by using the finite element simulation method, including: changing the inclination angle of the central column, simulating the joint stress distribution under different welding pressures, welding temperatures, and welding times, and finally determining the inclination angle of the central column.

[0039] Compared with the prior art, the present invention has the following technical effects:

[0040] According to the technical requirements of aerospace centrifugal turbines for hub / disk heterogeneous material alloy structural parts, the present invention has established an optimal diffusion welding process route, which largely eliminates interfacial residual pores, improves the bearing capacity and crack resistance of joints; in cooperation with the designed vertical weld auxiliary compression device, it can ensure uniform compression of vertical welds, thereby enabling sufficient welding in the low-pressure area and further avoiding the formation of interfacial pores, improving the strength connection at the joint, and ensuring its long-life and high-strength application; at the same time, it also reduces the deformation amount in the high-pressure area and avoids local dimensional out-of-tolerance of parts. Brief Description of the Drawings

[0041] Figure 1 It is a schematic assembly structure diagram of a hub / disk heterogeneous material alloy structural part and a vertical weld auxiliary compression device.

[0042] Figure 2 It is a schematic structural diagram of a disk; Figure 2 In it: (a) is a front view; (b) is a sectional view.

[0043] Figure 3 It is a schematic structural diagram of a hub; Figure 3 In it: (a) is a front view; (b) is a sectional view.

[0044] Figure 4 It is a schematic structural diagram of a central column; Figure 4 In it: (a) is a front view; (b) is a sectional view.

[0045] Figure 5 It is a schematic structural diagram of a limit ring; Figure 5 In it: (a) is a front view; (b) is a sectional view.

[0046] Figure 6 It is a schematic structural diagram of an outer sleeve ring; Figure 6 In it: (a) is a front view; (b) is a sectional view.

[0047] Figure 7 It is a schematic structural diagram of a washer; Figure 7 In it: (a) is a front view; (b) is a sectional view.

[0048] The meanings of the reference numerals in the figure are: 1 - hub, 2 - disk, 3 - central column, 4 - outer sleeve ring, 5 - limit ring, 6 - washer.

[0049] The following further explains the specific content of the present invention in detail with reference to embodiments. Detailed Embodiment

[0050] It should be noted that all materials, software, and experimental methods in the present invention, unless otherwise specified, are those known in the art. For example:

[0051] The solder mask adopts a conventional solder mask known in the prior art, and its main components are epoxy resin, acrylic resin or polyurethane resin.

[0052] The hot simulation compression experiment adopts a conventional method known in the prior art, such as the method described in the national standard (GB / T44030-2024).

[0053] The modeling software adopts the conventional Solidworks modeling software known in the prior art.

[0054] The finite element software adopts the conventional ABAQUS simulation software known in the prior art.

[0055] The following are specific embodiments of the present invention. It should be noted that the present invention is not limited to the following specific embodiments, and any equivalent transformation based on the technical solution of this application falls within the protection scope of the present invention.

[0056] Embodiment 1:

[0057] This embodiment provides a hub / disk heterogeneous material alloy structural member, including a hub 1 and a disk 2. The hub 1 and the disk 2 are made of different alloys. The hub 1 is made of titanium alloy; the disk 2 is made of one or more of Inconel718 alloy, GH4738 alloy, GH4720Li alloy and Inconel718Plus. The reason is that when the centrifugal turbine works, the heat distribution of the entire turbine disk gradually increases from the central hole to the outer disk. Therefore, a more heat-resistant alloy is required.

[0058] Embodiment 2:

[0059] This embodiment provides a vertical weld auxiliary compression device for processing the hub / disk heterogeneous material alloy structural member of Embodiment 1, as Figures 1 to 7 shown, including a central column 3 with a frustum structure, an outer sleeve 4, a limiting ring 5 and a washer 6; the central hole of the hub 1 is sleeved on the central column 3, and the inclination angle of the central hole of the hub 1 is the same as that of the central column 3; the disk 2 is assembled on the outside of the hub 1, and a washer 6 is provided on the lower end surfaces of the hub 1 and the disk 2; the limiting ring 5 is sleeved on the outside of the large end of the central column 3 and is in close contact with the upper end surface of the hub 1; the outer sleeve 4 is sleeved on the outside of the disk 2.

[0060] In this embodiment, the function of the central column 3 is to apply welding pressure to the hub 1 and the disk 2 during the continuous pressure application process of diffusion welding; the function of the limiting ring 5 is to prevent the upper end of the central column 3 from being thickened due to the extrusion force during welding; the function of the outer sleeve 4 is to prevent the disk 2 from being thickened due to the extrusion force during the welding process, resulting in dimensional tolerance; the function of the washer 6 is to partially extrude the central column 3, so as to apply uniform pressure to the weld.

[0061] As a specific solution of this embodiment, the central column 3 is made of superalloys such as Inconel 625 alloy, GH4169 alloy, Haynes 282 alloy, and GH4090 alloy. The reason is that during diffusion welding, the pressure is mainly concentrated on the central column 3. Therefore, it is necessary to maintain relatively high strength at the diffusion welding temperature. The outer ring 4, the limiting ring 5, and the washer 6 are made of graphite. The graphite material can still maintain rigidity in the high-temperature environment of diffusion welding, which can ensure that the deformation of the structural components before and after welding is small.

[0062] Example 3:

[0063] This embodiment provides a process design method for a hub / disk heterogeneous material alloy structural component of Example 1. This method uses computer simulation to design the process parameters of diffusion welding. The method specifically includes the following steps:

[0064] Step 1, welding temperature design:

[0065] For superalloys and titanium alloys, based on the characteristic temperature points, diffusion welding experiments at different welding temperatures are designed and carried out to obtain the influence laws of welding temperature on interface bonding rate, joint phase composition and distribution, grain size, etc. Through Thermo-Calc thermodynamic simulation software, the thermodynamic criteria and laws for the formation of joint phases at different welding temperatures are established, and the influence laws of welding temperature on the diffusion welding forming of superalloys and titanium alloys are obtained. Finally, the optimal welding temperature is determined to be 860 °C. During subsequent actual welding, it is carried out in the range of 840 °C to 900 °C.

[0066] Step 2, welding pressure design:

[0067] In the diffusion welding temperature range of two heterogeneous alloys, thermal simulation compression experiments are carried out to obtain the strain-time curves of each material, and the corresponding creep constitutive equations are established. Since superalloys and titanium alloys are in the first stage of creep in the welding pressure and welding temperature ranges studied in this work, the creep model adopts the power-law form suitable for the first stage, that is, the Norton formula of stress hardening and the power-law form of time hardening creep constitutive. ABAQUS has built-in the material creep constitutive of this form, as shown in Equation Ⅰ below:

[0068]

[0069] In the formula: is the creep strain rate of the material, σ is the nominal stress, t is the creep time; m is the material constant in the first stage of creep; n is the creep exponent, dimensionless, which represents the relationship between creep strain and creep stress and reflects the creep deformation characteristics and stability of the material; C is the material constant; C, n, and m can be determined by thermal simulation compression experiments.

[0070] Use modeling software to construct a diffusion welding interface pore closure model, and then use the finite element simulation method to carry out the simulation of the diffusion welding process with vertical weld pressurization. Incorporate the creep constitutive equation into the diffusion welding interface pore closure model to study the deformation law of specimens under different combinations of process parameters, and finally determine that the optimal welding pressure is 6t. The subsequent actual welding is carried out in the range of 5t to 8t.

[0071] Step three, welding time design:

[0072] Based on the principle of micropore closure at the solid-phase diffusion welding interface, use the finite element simulation method to simulate the process of heterogeneous alloy interface bonding; on the basis of heterogeneous alloy diffusion welding with vertical weld pressurization, establish an initial geometric model of micropores at the interface; based on the creep constitutive equations of each material, study the influence laws of welding temperature, welding pressure, welding time, and surface roughness on the closure of micropores at the interface, obtain the evolution law of micropore size at the interface over time, and finally determine that the optimal welding time is 90 min. The subsequent actual welding is carried out in the range of 70 min to 130 min.

[0073] Step four, design of the auxiliary compression device for the vertical weld:

[0074] For the size of the centrifugal turbine parts, use the finite element simulation method to design and optimize the inclination angle of the central column of the auxiliary compression device for the vertical weld; change the inclination angle α of the central column 3, and simulate the joint stress distribution under different welding pressures, welding temperatures, and welding times; finally determine that the inclination angle α of the central column 3 is 100°, and the auxiliary compression device for the vertical weld is as Figure 4 、 Figure 5 、 Figure 6 and Figure 7 shown.

[0075] Example 4:

[0076] This example presents a processing method for a hub / disk heterogeneous material alloy structural component, which specifically includes the following steps:

[0077] Step one, rough machining:

[0078] Step 1.1, blanking: According to the design dimensions of the disk 2 and the hub 1, forge and cut the superalloy and titanium alloy materials to obtain a blank with a preliminary shape.

[0079] Step 1.2, Clamping and Positioning: Use a tooling fixture to clamp the blank on the processing equipment to ensure firm clamping and accurate positioning. Adopt a three-jaw self-centering chuck or other fixtures and use the upper surface of the blade disk 2 as the reference for clamping and positioning. Use a special positioning tool (such as a conical positioning block) to ensure that both sides of the blade disk 2 are in contact and can move up and down to compensate for the errors generated during the process.

[0080] Step 1.3, Rough Turning: Use a CNC lathe to perform rough turning on the blank to remove excess material and form the approximate contour of the blade disk 2. Use a CNC lathe to perform rough machining on the blade disk 2 and the hub 1, mainly including turning the end face of the blade disk, turning the circumferential surface of the blade disk, and turning the inner hole.

[0081] Step Two, Finish Machining:

[0082] According to the shapes and dimensions of the hub 1 and the blade disk 2 after rough machining, perform necessary trimming and semi-finish machining to make the dimensions of the parts reach the final dimensions. Finish machine the mating surfaces of the hub 1 and the blade disk 2 to ensure the surface finish and roughness, and ensure the mating tolerance between the two, where the roughness is Ra 1.6μm. Among the dimensions of the bimetallic hub 1 and the blade disk 2, the mating dimensions of the hub 1 and the blade disk 2 are critical dimensions, and it is required that the two can be closely mated.

[0083] Step Three, Inspection and Assembly:

[0084] Step 3.1, Quality Inspection: Inspect the machined hub 1 and blade disk 2 for dimensions, shapes, cracks, etc. to ensure that the quality of the hub 1 and blade disk 2 meets the design requirements.

[0085] Step 3.2, Assemble Structural Parts: Fine-assemble the hub 1 and the blade disk 2, paying attention to factors such as the alignment of the parts, the parts with bevel fits, and the force. Perform necessary cleaning and anti-rust treatment on the assembled blade disk 2 to ensure that the welding surface is clean and the dimensions are accurate before welding.

[0086] Step Four, Diffusion Welding:

[0087] Step 4.1, Install the Auxiliary Compression Device for Vertical Welds: First, apply Keller reagent to the hub 1 and the blade disk 2 for surface activation. After drying, assemble the hub 1 and the blade disk 2. Then, spray a welding resistance agent on the contact parts of the vertical weld auxiliary compression device and the structural parts. Finally, install the vertical weld auxiliary compression device on the structural parts.

[0088] Step 4.2, Perform Welding: Place the assembled vertical weld auxiliary compression device and the structural parts in a diffusion furnace, close the furnace door, evacuate, and keep the vacuum degree p less than or equal to 5×10 -3Pa; During diffusion welding, the temperature is increased at a rate of 10 °C / min to 860 °C, then a pressure of 6 t is applied and it is kept warm for 90 min. After that, the heating power supply is turned off, and it is cooled in the furnace to room temperature and taken out to obtain a hub / disk heterogeneous material alloy structural part.

[0089] In this embodiment, the finally processed hub / disk heterogeneous material alloy structural part meets the following technical index requirements: a. Mechanical property index: The tensile strength of the diffusion welding seam joint (at room temperature and 450 °C) is not less than 90% of the matrix strength; the high-cycle fatigue strength of the diffusion welding seam joint at room temperature is not less than 90% of the matrix strength; the creep life of the diffusion welding seam joint under the conditions of 450 °C and 600 MPa is not less than 100 hours; b. Relevant standards: The inspection result after welding refers to the relevant requirements of Grade I weld in AETF320A "Solid Phase Diffusion Welding of Titanium Alloys"; c. Welding rate: The welding rate is not less than 98%. It meets the technical requirements of aeroengine turbines.

[0090] Example 5:

[0091] This embodiment provides a processing method for the hub / disk heterogeneous material alloy structural part of Example 1. This method is basically the same as that of Example 4, except that the diffusion welding temperature is 880 °C.

[0092] In this embodiment, the finally obtained hub / disk heterogeneous material alloy structural part meets the following technical index requirements: a. Mechanical property index: The tensile strength of the diffusion welding seam joint (at room temperature and 450 °C) is not less than 90% of the matrix strength; the high-cycle fatigue strength of the diffusion welding seam joint at room temperature is not less than 90% of the matrix strength; the creep life of the diffusion welding seam joint under the conditions of 450 °C and 600 MPa is not less than 100 hours; b. Relevant standards: The inspection result after welding refers to the relevant requirements of Grade I weld in AETF320A "Solid Phase Diffusion Welding of Titanium Alloys"; c. Welding rate: The welding rate is not less than 98%. It meets the technical requirements of aeroengine turbines.

[0093] Example 6:

[0094] This embodiment provides a processing method for the hub / disk heterogeneous material alloy structural part of Example 1. This method is basically the same as that of Example 4, except that the diffusion welding pressure is 7 t.

[0095] In this embodiment, the finally processed hub / disk heterogeneous material alloy structural part obtained finally meets the following technical index requirements: a. Mechanical property indexes: The tensile strength of the diffusion-welded joint (at room temperature and 450°C) is not less than 90% of the matrix strength; the high-cycle fatigue strength of the diffusion-welded joint at room temperature is not less than 90% of the matrix strength; the creep life of the diffusion-welded joint under the conditions of 450°C and 600 MPa is not less than 100 hours; b. Relevant standards: The post-weld inspection results refer to the relevant requirements of Class I welds in AETF320A "Solid-State Diffusion Welding of Titanium Alloys"; c. Welding combination rate: The welding combination rate is not less than 98%. It meets the technical requirements of aerospace engine turbines.

[0096] Example 7:

[0097] This embodiment provides a processing method for the hub / disk heterogeneous material alloy structural part of Embodiment 1. This method is basically the same as that of Embodiment 4, except that the diffusion welding time is 110 min.

[0098] In this embodiment, the finally processed hub / disk heterogeneous material alloy structural part obtained finally meets the following technical index requirements: a. Mechanical property indexes: The tensile strength of the diffusion-welded joint (at room temperature and 450°C) is not less than 90% of the matrix strength; the high-cycle fatigue strength of the diffusion-welded joint at room temperature is not less than 90% of the matrix strength; the creep life of the diffusion-welded joint under the conditions of 450°C and 600 MPa is not less than 100 hours; b. Relevant standards: The post-weld inspection results refer to the relevant requirements of Class I welds in AETF320A "Solid-State Diffusion Welding of Titanium Alloys"; c. Welding combination rate: The welding combination rate is not less than 98%. It meets the technical requirements of aerospace engine turbines.

[0099] Comparative Example 1:

[0100] This comparative example provides a processing method for the hub / disk heterogeneous material alloy structural part of Comparative Example 1. This method is basically the same as that of Embodiment 4, except that the diffusion welding temperature is 840°C.

[0101] In this comparative example, the creep life of the diffusion-welded joint of the finally obtained hub / disk heterogeneous material alloy structural part under the conditions of 450°C and 600 MPa is less than 100 hours, which does not meet the technical requirements of aerospace engine turbines.

[0102] Comparative Example 2:

[0103] This comparative example provides a processing method for the hub / disk heterogeneous material alloy structural part of Comparative Example 1. This method is basically the same as that of Embodiment 4, except that the diffusion welding temperature is 900°C.

[0104] In this comparative example, the creep life of the diffusion-welded joint of the hub / disk heterogeneous material alloy structural part obtained finally is less than 100 hours under the conditions of 450 °C and 600 MPa, not meeting the technical requirements of the turbine of the aerospace engine.

[0105] Comparative Example 3:

[0106] This comparative example provides a processing method for the hub / disk heterogeneous material alloy structural part of Comparative Example 1. This method is basically the same as that of Example 4, except that the diffusion welding pressure is 5 t.

[0107] In this comparative example, the tensile strength (at room temperature and 450 °C) of the diffusion-welded joint of the hub / disk heterogeneous material alloy structural part obtained finally is less than 90% of the matrix strength, not meeting the technical requirements of the turbine of the aerospace engine.

[0108] Comparative Example 4:

[0109] This comparative example provides a processing method for the hub / disk heterogeneous material alloy structural part of Comparative Example 1. This method is basically the same as that of Example 4, except that the diffusion welding pressure is 8 t.

[0110] In this comparative example, the creep life of the diffusion-welded joint of the hub / disk heterogeneous material alloy structural part obtained finally is less than 100 hours under the conditions of 450 °C and 600 MPa, not meeting the technical requirements of the turbine of the aerospace engine.

[0111] Comparative Example 5:

[0112] This comparative example provides a processing method for the hub / disk heterogeneous material alloy structural part of Comparative Example 1. This method is basically the same as that of Example 4, except that the diffusion welding time is 70 min.

[0113] In this comparative example, the bonding rate of the diffusion-welded joint of the hub / disk heterogeneous material alloy structural part obtained finally is less than 98%, not meeting the technical requirements of the turbine of the aerospace engine.

[0114] Comparative Example 6:

[0115] This comparative example provides a processing method for the hub / disk heterogeneous material alloy structural part of Comparative Example 1. This method is basically the same as that of Example 4, except that the diffusion welding time is 130 min.

[0116] In this comparative example, the diffusion-welded joint of the hub / disk heterogeneous material alloy structural part obtained finally does not meet the relevant requirements of Grade I welds in AETF320A "Solid Phase Diffusion Welding of Titanium Alloys", and the welding deformation amount > 0.1% of the length, not meeting the technical requirements of the turbine of the aerospace engine.

Claims

1. A processing method for a hub / disk heterogeneous material alloy structural member, characterized in that, It is processed by diffusion welding. During processing, radial and axial limits are applied to the hub (1) and the blisk (2). The process conditions of the diffusion welding include: in a vacuum environment, applying a welding pressure of 6t - 7t and holding for 90 - 110 min at a welding temperature of 860 - 880 °C.

2. The processing method of the hub / blisk heterogeneous material alloy structural member according to claim 1, characterized in that, The degree of vacuum in the vacuum environment is less than or equal to 5×10 -3 Pa.

3. The processing method of the hub / blisk heterogeneous material alloy structural member according to claim 1, wherein It is heated to the welding temperature at a heating rate of 5 - 15 °C / min.

4. The processing method of the hub / blisk heterogeneous material alloy structural member according to claim 1, characterized in that The said hub (1) is made of titanium alloy; the said blisk (2) is made of nickel-based alloy.

5. The processing method of the hub / blisk heterogeneous material alloy structural member according to claim 1, characterized in that Computer simulation is used to design the welding temperature, welding pressure and welding time of the diffusion welding. The welding temperature design includes: based on the material characteristic temperature points of the hub (1) and the blisk (2), designing and conducting diffusion welding experiments at different welding temperatures, obtaining the influence law of the welding temperature on the microstructure and structure of the materials of the hub (1) and the blisk (2); through thermodynamic simulation software, establishing the thermodynamic criterion and thermodynamic law for the formation of joint phases of the material microstructure at different welding temperatures based on the influence law of the microstructure and structure of the materials, thereby obtaining the influence law of the welding temperature on the diffusion welding forming of the materials of the hub (1) and the blisk (2), and finally determining the welding temperature range. The welding pressure design includes: within the welding temperature range, conducting hot simulation compression experiments to obtain the strain-time curves of the materials of the hub (1) and the blisk (2), and establishing the corresponding creep constitutive equation; constructing a diffusion welding interface hole closure model, and then using the finite element simulation method to conduct a simulation of the diffusion welding process with vertical weld pressurization, incorporating the creep constitutive equation into the diffusion welding interface hole closure model, simulating the specimen deformation law under different process parameter combinations, and finally determining the welding pressure range. The welding time design includes: using the finite element simulation method to simulate the process of the material interface welding of the hub (1) and the blisk (2); in the diffusion welding environment with vertical weld pressurization, establishing a micro-hole geometric model of the material interface; based on the creep constitutive equations of the materials of the hub (1) and the blisk (2), obtaining the influence law of the welding temperature, welding pressure, welding time and surface roughness on the closure of the interface micro-holes, further obtaining the evolution law of the micro-hole size of the material interface with the welding time, and finally determining the welding time range.

6. The processing method of the hub / blisk heterogeneous material alloy structural member according to claim 5, wherein The said creep constitutive equation is shown as formula Ⅰ below: In the formula: represents the creep strain rate of the material; σ represents the nominal stress; t represents the creep time; m represents the material constant in the first stage of creep; n represents the creep exponent; C represents the material constant.

7. A vertical weld assisted compression device for implementing the processing method of the hub / blisk dissimilar material alloy structural part as described in any one of claims 1 to 6.

8. The vertical weld auxiliary pressure-bearing device according to claim 7, wherein, It includes an outer sleeve (4), a limit ring (5), a washer (6) and a central column (3) with a frustum structure; the central hole of the hub (1) is sleeved on the central column (3), the blisk (2) is assembled on the outside of the hub (1), and the outer sleeve (4) is sleeved on the outside of the blisk (2); the limit ring (5) is sleeved on the outside of the large end of the central column (3) and is in close contact with the upper end face of the hub (1); washers (6) are arranged on the lower end faces of the hub (1) and the blisk (2).

9. The vertical weld bead auxiliary pressure-bearing device according to claim 8, characterized in that, The inclination angle of the said central column (3) is 80° - 120°.

10. The vertical weld seam auxiliary pressure-bearing device according to claim 8, wherein, The described central column (3) is made of a nickel-based alloy; the described outer sleeve ring (4), limiting ring (5) and washer (6) are made of graphite.

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