Mixed powder, preparation method and application of mixed powder in welding of double-web turbine disc

Abstract

The invention discloses mixed powder, a preparation method and application of the mixed powder in welding of a double-radial-plate turbine disc, and belongs to the technical field of welding. The method is used for solving the problems that in the prior art, high-temperature long-time heat preservation is needed for traditional transient liquid phase diffusion welding (TLP) used for welding of the double-radial-plate turbine disc, high-temperature alloy base metal grains grow up, a precipitation strengthening phase is re-dissolved, and the base metal performance is reduced, and mixed powder comprises, by mass, 1-3% of base metal particles and the balance nickel-based powder; the nickel-based powder comprises the following element components in percentage by weight: 7 to 8 percent of Cr, 9.8 to 10.2 percent of Co, 2.1 to 2.4 percent of Mo, 2 to 2.8 percent of B, 0.8 to 1.6 percent of Hf, 0.2 to 0.6 percent of Si, 4.1 to 6.8 percent of W, 3 to 3.5 percent of Al, 2.3 to 3.1 percent of Ti and the balance of nickel; the prepared mixed powder interlayer for TLP diffusion welding has good high-toughness connection application in double-radial-plate turbine disc welding, diffusion channels and diffusible areas of melting reduction elements can be increased, the diffusion rate is increased, the TLP isothermal solidification process is accelerated, and connection under the low heat damage technology is achieved.

Description

Technical Field

[0001] The present invention relates to the field of welding technology, and particularly relates to a mixed powder, a preparation method thereof, and an application thereof in the welding of a dual-web turbine disk. Background Art

[0002] At present, airplanes have become an essential means of transportation in life. As the "heart" of an airplane, an aeroengine has a complex structure and a large number of components, and is a decisive factor for the performance, reliability, and cost of an airplane. A high thrust-to-weight ratio is one of the four main goals pursued by modern aeroengines. Under the current international situation, the manufacture of advanced aeroengines with a high thrust-to-weight ratio has become an important indicator for measuring a country's national defense strength and manufacturing level, and is also a key area of competition among major powers. To achieve the design goal of a high thrust-to-weight ratio, there are usually two methods. One is to increase the intake air temperature to increase the thrust, and the other is to optimize the engine structure to reduce the weight. The traditional turbine disk is a solid structure, and the cold air can only flow through the disk surface for cooling, resulting in uneven temperature distribution and large thermal stress on the turbine disk. The new generation of turbine disks has been replaced from the traditional solid structure to a hollow dual-web structure, which has a precise and complex cavity. Such a design can, on the one hand, reduce the self-weight of the turbine disk and thus reduce its centrifugal force, and on the other hand, the inside of the cavity can be cooled, thereby increasing the service temperature of the turbine disk.

[0003] At present, the material used for the dual-web turbine disk can be the third-generation powder superalloy FGH99. This alloy combines the high strength of the first-generation powder superalloy and the damage tolerance design of the second-generation powder superalloy, and is a high-strength damage tolerance alloy with higher creep strength and crack propagation resistance. It should be noted that the application of powder metallurgy superalloys relies on the support of precision welding technology. Among them, transient liquid phase diffusion welding (TLP) is a widely used joining method for powder metallurgy superalloys with high alloying degree, difficult deformation, and high solution temperature. The working mechanism of TLP is as follows: low melting point elements such as Si and B are added to the interlayer, so that the melting point of the interlayer is lower than that of the base material. During welding, when the temperature is set slightly higher than the melting point of the interlayer, the interlayer will melt, and then a liquid film will be formed; this liquid film can wet the surface of the base material, thereby constructing a dense connection interface. After that, through a long-time heat preservation operation, the melting point-lowering elements Si, B, etc. in the interlayer diffuse into the base material. This diffusion process will increase the melting point of the remaining liquid phase, and then promote the occurrence of isothermal solidification; extending the heat preservation time can further homogenize the structure and composition, and form a reliable connection. However, the main problems existing in this welding method at present are: the required isothermal solidification time is relatively long, resulting in the deterioration of the base material performance. If the welding time is shortened, the melting point-lowering elements are likely to accumulate in the weld center, easily forming a large number of brittle borides and reducing the joint strength.

[0004] Chinese Patent CN112008224B discloses a connection method for a double-web hollow turbine disk made of powder superalloy. This invention takes solid-phase diffusion connection as the core and eliminates the original connection interface of the joint through process measures such as precise preparation of the welding interface, design and optimization of the diffusion connection process curve, and heat treatment for restoring performance after welding, realizing reliable connection of powder superalloys and improving the structural integrity and service performance of the turbine disk; however, the process is complicated and not suitable for large-scale popularization and use. Chinese Patent CN112077430B discloses a diffusion welding method and welded products, using an A1CoCrFeNi-based high-entropy alloy as an intermediate layer to perform diffusion welding on IC10 single crystals and nickel-based superalloys. This diffusion welding can reduce the formation of carbides, improve the strength of the welded material, and reduce the dilution of alloy solutes in the heat-affected zone of the base material, improving the performance of the heat-affected zone; among them, the intermediate layer alloy needs to be melted multiple times to ensure uniform composition, and the heating and holding processes of diffusion welding are time-consuming, making it difficult to meet the requirements of large-scale production for efficiency and restricting the improvement of production capacity. Summary of the Invention

[0005] To solve the above technical problems, the present invention provides a mixed powder, a preparation method, and an application in the welding of double-web turbine disks, solving the problem that the traditional transient liquid-phase diffusion welding used for welding double-web turbine disks requires high-temperature and long-time heat preservation, which causes grain growth of the superalloy base material, re-dissolution of precipitation strengthening phases, and reduction of the base material performance; moreover, compared with the traditional transient liquid-phase diffusion welding, the TLP diffusion welding method for double-web turbine disks provided by the present invention has a lower temperature and a shorter heat preservation time, reducing energy consumption and improving production efficiency.

[0006] To achieve the above object, the present invention provides a preparation method for a mixed powder, comprising the following steps:

[0007] Process the powder metallurgy superalloy base material FGH99 into base material particles with a particle size of 50 - 90 μm; mix the base material particles and nickel-based powder and grind to obtain a mixed powder;

[0008] Wherein, in the mixed powder, the base material particles account for 1 - 3% by mass percentage, and the balance is nickel-based powder;

[0009] Wherein, the weight percentages of each element component in the nickel-based powder are Cr 7 - 8%, Co 9.8 - 10.2%, Mo 2.1 - 2.4%, B 2 - 2.8%, Hf 0.8 - 1.6%, Si 0.2 - 0.6%, W 4.1 - 6.8%, Al 3 - 3.5%, Ti 2.3 - 3.1%, and the balance is nickel.

[0010] Preferably, the specific operation of grinding is: ball milling in a planetary ball mill at a rotation speed of 200 - 300 rpm for 20 - 40 min.

[0011] The present invention also provides a mixed powder interlayer for TLP diffusion welding, which is prepared by mixing the mixed powder obtained by the preparation method of the mixed powder with a binder to form a slurry and then drying it.

[0012] Preferably, the binder is terpineol.

[0013] Preferably, the mass ratio of the mixed powder to the binder is (7 - 10):1.

[0014] The present invention also provides a TLP diffusion welding method for a double - web turbine disk, comprising the following steps:

[0015] Step (1): Grinding, polishing, cleaning, and drying the surface of the workpiece of the double - web turbine disk to be welded to obtain a treated workpiece;

[0016] Step (2): Assembling the treated workpieces, and applying the mixed powder interlayer for TLP diffusion welding between the welding interfaces to obtain a sandwich structure of double - web turbine disk half - disk / mixed powder interlayer for TLP diffusion welding / double - web turbine disk half - disk;

[0017] Step (3): Placing the sandwich - structured workpiece obtained in step (2) into a vacuum diffusion welding furnace, heating, holding, cooling, and performing non - destructive testing to obtain a welded double - web turbine disk.

[0018] Preferably, in step (1), the abrasive used for grinding is sandpaper with a grit size of 160# - 2000#.

[0019] Preferably, in the vacuum diffusion welding furnace, the heating temperature is 1090 - 1130 °C, the pressure is 4 - 6 MPa, and the holding time is 55 - 65 min.

[0020] Preferably, the heating rate during the heating process is 10 °C / min.

[0021] Preferably, in step (1), the polishing agent used is silica.

[0022] Preferably, in step (1), the cleaning agent used is anhydrous ethanol.

[0023] Preferably, in step (2), the thickness of the mixed powder interlayer for TLP diffusion welding is 50 - 100 μm.

[0024] A double - web turbine disk is obtained by using the TLP diffusion welding method for a double - web turbine disk described above.

[0025] Compared with the prior art, the beneficial effects of the present invention are:

[0026] 1. In the present invention, nickel-based powder is mixed with FGH99 base metal particles to obtain a mixed powder, which is then mixed with a binder to form a slurry. After drying, a mixed powder interlayer for TLP diffusion welding is obtained. In the welding method, the addition of the mixed powder increases the diffusion channels of the melting point depressing elements, significantly improves the diffusion rate of the melting point depressing elements, significantly reduces the temperature and holding time required for welding, and accelerates the isothermal solidification process. Compared with traditional transient liquid phase diffusion welding, the reduction of the temperature and holding time required in the present invention reduces the risks of grain growth of the base metal and dissolution of strengthening phases, reduces thermal damage, is conducive to maintaining the properties of the base metal, reduces energy consumption, and improves production efficiency; the preparation process of the present invention is simple and the required cost is low, which is suitable for large-scale production.

[0027] 2. In the TLP diffusion welding method of the double web turbine disk provided by the present invention, when the alloying elements in the weld and the alloying elements in the base metal diffuse and fuse with each other, a region with a gradually changing composition is formed instead of an obvious interface, which enhances the bonding strength between the weld and the base metal, reduces the weak links at the joint, improves the reliability of the overall structure of the double web turbine disk, and a higher degree of weld alloying promotes more sufficient metallurgical bonding between the weld and the base metal. This alloying effect makes the composition of the weld region more uniform and the mechanical properties close to those of the base material, thus achieving high-strength connection. At the same time, the uniform distribution of alloying elements in the weld helps to optimize the microstructure of the weld, thereby improving the service life and safety of the double web turbine disk. At the same time, the present invention provides a new idea for difficult-to-weld materials, especially materials such as superalloys that are difficult to process by traditional methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is the process flow chart of the TLP diffusion welding process of the double web turbine disk in the present invention;

[0029] Figure 2 is the SEM micrograph of the diffusion welded joint of the half disk of the double web turbine disk in Example 1 of the present invention;

[0030] Figure 3 is the SEM micrograph of the diffusion welded joint of the half disk of the double web turbine disk in Example 4 of the present invention;

[0031] Figure 4 is the SEM micrograph of the diffusion welded joint of the half disk of the double web turbine disk in Example 5 of the present invention;

[0032] Figure 5 is the bar chart of the tensile strength test results of the mixed powder interlayer for TLP diffusion welding and the comparative example in Examples 1-5 of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0033] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0034] Embodiment 1

[0035] This embodiment provides a TLP diffusion welding method for a dual-web turbine disk, including the following steps:

[0036] Step (1): The surface of the dual-web turbine disk workpiece to be welded is successively polished with 160#, 200#, 400#, 600#, 800#, 1000#, 1200#, 1600#, 1800#, and 2000# metallographic sandpapers for 5 minutes each, polished with 0.15 μm silica polishing liquid until there are no obvious scratches on the surface, ultrasonically cleaned with anhydrous ethanol at a frequency of 20 kHz for 15 minutes, and dried with a nitrogen gun to obtain the treated workpiece.

[0037] Step (2): Assemble the treated workpieces, and apply a mixed powder interlayer with a thickness of 40 μm for TLP diffusion welding between the welding interfaces to obtain a sandwich structure of dual-web turbine disk half-disk / TLP diffusion welding mixed powder interlayer / dual-web turbine disk half-disk.

[0038] Among them, the preparation method of the mixed powder interlayer for TLP diffusion welding includes the following steps:

[0039] The powder metallurgy superalloy base material FGH99 is processed into base material particles with a particle size of 50 μm by the rotating electrode atomization method, and then ball-milled with nickel-based powder in a planetary ball mill at a rotation speed of 200 rpm for 40 minutes to obtain a mixed powder; the mixed powder and terpineol are fully mixed according to a mass ratio of 7:1 to form a slurry, and dried at 60 °C for 5 hours to obtain the mixed powder interlayer for TLP diffusion welding.

[0040] Among them, in the mixed powder, the base material particles account for 1% by mass percentage, and the balance is nickel-based powder.

[0041] Among them, the weight percentages of the various elemental components in the nickel-based powder are Cr 7%, Co 9.8%, Mo 2.1%, B 2%, Hf 0.8%, Si 0.2%, W 4.1%, Al 3%, Ti 2.3%, and the balance is nickel.

[0042] Step (3): Put the sandwich structure workpiece obtained in step (2) into a vacuum diffusion welding furnace. Wait until the vacuum degree is pumped to 1×10 -3Pa, heat from room temperature to 300 °C at a rate of 10 °C / min, hold for 10 min, then heat to 700 °C at a rate of 10 °C / min, hold for 10 min, then heat to 1090 °C at a rate of 10 °C / min, hold for 65 min, apply a pressure of 4 MPa during the holding period, remove the pressure after the holding is completed, cool in the furnace to room temperature, and perform non-destructive testing to obtain the welded double-web turbine disk (the microstructure of the diffusion welding joint of the double-web turbine disk half-disk is as shown in Figure 2 shown).

[0043] Example 2

[0044] This example provides a TLP diffusion welding method for a double-web turbine disk, including the following steps:

[0045] Step (1): Gradually polish the surface of the workpiece of the double-web turbine disk to be welded with 160#, 200#, 400#, 600#, 800#, 1000#, 1200#, 1600#, 1800#, 2000# metallographic sandpaper for 5 min each, polish with 0.15 μm silica polishing liquid until there are no obvious scratches on the surface, ultrasonically clean the pre-welding part with anhydrous ethanol at a frequency of 20 kHz for 15 min, and dry with a nitrogen gun to obtain the treated workpiece;

[0046] Step (2): Assemble the treated workpieces, and apply a TLP diffusion welding mixed powder interlayer with a thickness of 40 μm between the welding interfaces to obtain a sandwich structure of double-web turbine disk half-disk / TLP diffusion welding mixed powder interlayer / double-web turbine disk half-disk;

[0047] Among them, the preparation method of the TLP diffusion welding mixed powder interlayer includes the following steps:

[0048] Process the powder metallurgy superalloy base material FGH99 into base material particles with a particle size of 50 μm by the rotating electrode atomization method, and then ball mill with nickel-based powder in a planetary ball mill at a speed of 200 rpm for 40 min to obtain a mixed powder; fully mix the mixed powder and terpineol in a mass ratio of 7:1 to make a slurry, and dry at 60 °C for 5 h to obtain the TLP diffusion welding mixed powder interlayer;

[0049] Among them, in the mixed powder, calculated by mass percentage, the base material particles account for 2%, and the balance is nickel-based powder;

[0050] Among them, the weight percentages of the elements in the nickel-based powder are Cr 7%, Co 9.8%, Mo 2.1%, B 2%, Hf 0.8%, Si 0.2%, W 4.1%, Al 3%, Ti 2.3%, and the balance is nickel;

[0051] Step (3) Place the sandwich-structured workpiece obtained in step (2) into a vacuum diffusion welding furnace. When the vacuum degree is pumped to 1×10 -3 Pa, heat it from room temperature to 300°C at a rate of 10°C / min, hold for 10 min, then heat it to 700°C at a rate of 10°C / min, hold for 10 min, and then heat it to 1090°C at a rate of 10°C / min, hold for 65 min. Apply a pressure of 4 MPa during the holding period. After the holding is completed, remove the pressure and cool it to room temperature with the furnace. Perform non-destructive testing to obtain a double-web turbine disk with welding completed.

[0052] Example 3

[0053] This example provides a TLP diffusion welding method for a double-web turbine disk, including the following steps:

[0054] Step (1) Gradually polish the surface of the workpiece of the double-web turbine disk to be welded with 160#, 200#, 400#, 600#, 800#, 1000#, 1200#, 1600#, 1800#, 2000# metallographic sandpapers for 5 min each. Polish it with 0.15 μm silica polishing liquid until there are no obvious scratches on the surface. Ultrasonically clean the pre-welding part with anhydrous ethanol at a frequency of 20 kHz for 15 min, and dry it with a nitrogen gun to obtain the processed workpiece;

[0055] Step (2) Assemble the processed workpieces, and apply a TLP diffusion welding mixed powder interlayer with a thickness of 40 μm between the welding interfaces to obtain a sandwich structure of double-web turbine disk half-disk / TLP diffusion welding mixed powder interlayer / double-web turbine disk half-disk;

[0056] Among them, the preparation method of the TLP diffusion welding mixed powder interlayer includes the following steps:

[0057] Process the powder metallurgy superalloy base material FGH99 into base material particles with a particle size of 50 μm by the rotating electrode atomization method, and then ball mill it with nickel-based powder in a planetary ball mill at a speed of 200 rpm for 40 min to obtain a mixed powder; fully mix the mixed powder and terpineol in a mass ratio of 7:1 to make a slurry, and dry it at 60°C for 5 h to obtain the TLP diffusion welding mixed powder interlayer;

[0058] Among them, in the mixed powder, calculated by mass percentage, the base material particles account for 3%, and the balance is nickel-based powder;

[0059] Among them, the weight percentages of each element component in the nickel-based powder are Cr 7%, Co 9.8%, Mo 2.1%, B 2%, Hf 0.8%, Si 0.2%, W 4.1%, Al 3%, Ti 2.3%, and the balance is nickel;

[0060] Step (3): Place the sandwich-structured workpiece obtained in step (2) into a vacuum diffusion bonding furnace. When the vacuum degree is pumped to 1×10 -3 Pa, heat it from room temperature to 300°C at a rate of 10°C / min, hold for 10 min, then heat it to 700°C at a rate of 10°C / min, hold for 10 min, and then heat it to 1090°C at a rate of 10°C / min, hold for 65 min. Apply a pressure of 4 MPa during the holding period. After the holding ends, release the pressure and cool it in the furnace to room temperature. Conduct non-destructive testing to obtain the double web turbine disk with welding completed.

[0061] Example 4

[0062] This example provides a TLP diffusion welding method for a double web turbine disk, including the following steps:

[0063] Step (1): Gradually polish the surface of the double web turbine disk workpiece to be welded with 160#, 200#, 400#, 600#, 800#, 1000#, 1200#, 1600#, 1800#, 2000# metallographic sandpapers for 5 min each. Polish it with 0.15 μm silica polishing liquid until there are no obvious scratches on the surface. Ultrasonically clean the pre-welding part with absolute ethanol for 15 min, and dry it with a nitrogen gun to obtain the processed workpiece;

[0064] Step (2): Assemble the processed workpieces, and apply a TLP diffusion welding mixed powder interlayer with a thickness of 50 μm between the welding interfaces to obtain a sandwich structure of double web turbine disk half-disk / TLP diffusion welding mixed powder interlayer / double web turbine disk half-disk;

[0065] Among them, the preparation method of the TLP diffusion welding mixed powder interlayer includes the following steps:

[0066] Process the powder metallurgy superalloy base material FGH99 into base material particles with a particle size of 70 μm by the rotating electrode atomization method, and then ball mill it with nickel-based powder in a planetary ball mill at a speed of 250 rpm for 30 min to obtain a mixed powder; fully mix the mixed powder and terpineol in a mass ratio of 8:1 to make a slurry, and dry it at 70°C for 4 h to obtain the TLP diffusion welding mixed powder interlayer;

[0067] Among them, in the mixed powder, calculated by mass percentage, the base material particles account for 2%, and the balance is nickel-based powder;

[0068] Among them, the weight percentages of each element component in the nickel-based powder are Cr 7.5%, Co 10%, Mo 2.3%, B 2.4%, Hf 1.2%, Si 0.4%, W 5.45%, Al 3.3%, Ti 2.7%, and the balance is nickel;

[0069] Step (3): Place the sandwich-structured workpiece obtained in step (2) into a vacuum diffusion welding furnace. When the vacuum degree is pumped to 1×10 -3 Pa, heat it from room temperature to 300°C at a rate of 10°C / min, hold for 10 min, then heat it to 700°C at a rate of 10°C / min, hold for 10 min, and then heat it to 1110°C at a rate of 10°C / min, hold for 60 min. Apply a pressure of 5 MPa during the holding period. After the holding ends, release the pressure and cool it in the furnace to room temperature. Conduct non-destructive testing to obtain the welded double-web turbine disk (the microstructure of the diffusion welding joint of the double-web turbine disk half-disk is as shown in Figure 3 ).

[0070] Example 5

[0071] This example provides a TLP diffusion welding method for a double-web turbine disk, including the following steps:

[0072] Step (1): Gradually polish the surface of the workpiece of the double-web turbine disk to be welded with 160#, 200#, 400#, 600#, 800#, 1000#, 1200#, 1600#, 1800#, and 2000# metallographic sandpapers for 5 min each. Polish it with 0.15-μm silica polishing liquid until there are no obvious scratches on the surface. Ultrasonically clean the pre-welding part with anhydrous ethanol at a frequency of 20 kHz for 15 min, and dry it with a nitrogen gun to obtain the processed workpiece;

[0073] Step (2): Assemble the processed workpieces, and apply a mixed powder interlayer with a thickness of 60 μm for TLP diffusion welding between the welding interfaces to obtain a sandwich structure of double-web turbine disk half-disk / TLP diffusion welding mixed powder interlayer / double-web turbine disk half-disk;

[0074] Among them, the preparation method of the mixed powder interlayer for TLP diffusion welding includes the following steps:

[0075] Process the powder metallurgy superalloy base material FGH99 into base material particles with a particle size of 90 μm by the rotating electrode atomization method, and then ball-mill it with nickel-based powder in a planetary ball mill at a speed of 300 rpm for 20 min to obtain a mixed powder. Mix the mixed powder and terpineol in a mass ratio of 10:1 to make a slurry, and dry it at 80°C for 3 h to obtain the mixed powder interlayer for TLP diffusion welding;

[0076] Among them, in the mixed powder, the base material particles account for 3% by mass percentage, and the balance is nickel-based powder;

[0077] Among them, the weight percentages of the elements in the nickel-based powder are Cr 8%, Co 10.2%, Mo 2.4%, B 2.8%, Hf 1.6%, Si 0.6%, W 6.8%, Al 3.5%, Ti 3.1%, and the balance is nickel;

[0078] Step (3): Place the sandwich-structured workpiece obtained in step (2) into a vacuum diffusion welding furnace. When the vacuum degree is pumped to 1×10 -3 Pa, heat from room temperature to 300°C at a rate of 10°C / min, hold for 10 min, then heat to 700°C at a rate of 10°C / min, hold for 10 min, and then heat to 1130°C at a rate of 10°C / min, hold for 55 min. During the holding period, apply a pressure of 6 MPa. After the holding ends, release the pressure and cool to room temperature with the furnace. Perform non-destructive testing to obtain the welded double-web turbine disk (the microstructure of the diffusion welding joint of the double-web turbine disk half-disk is as Figure 4 shown).

[0079] In the present invention, the material used for the double-web turbine disk workpiece in the embodiment is the powder metallurgy superalloy FGH99.

[0080] Test the tensile strength at room temperature of the TLP diffusion welding intermediate alloy of the mixed powder in Examples 1-5 according to the standard of "GB / T 228.1-2021: Metallic materials - Tensile testing - Part 1: Method of test at room temperature". Among them, the alloy FGH99 is used in the comparative example. The specific test results are shown in Table 1;

[0081] Table 1

[0082]

[0083] According to the test results in Table 1, the mixed powder interlayer for TLP diffusion welding prepared by the present invention has good wettability and diffusibility. The alloy of the mixed powder interlayer for TLP diffusion welding provided in Example 4 reaches 90% of the tensile strength of the base alloy FGH99, indicating that the mixed powder interlayer for TLP diffusion welding of the present invention can effectively achieve high-strength metallurgical bonding. By observing the SEM images of the diffusion welding joints of the double-web turbine disk half disks in Example 1, Example 4, and Example 5 of the present invention, it can be seen that the welding effect of Example 4 is the best, mainly because: as can be seen from the scanning electron microscope images, the interface between the mixed powder interlayer for TLP diffusion welding and the base material is blurred, the element gradient transition is gentle, and the continuous diffusion layer indicates sufficient metallurgical bonding, reducing the brittle phase at the interface and having few defects at the connection interface; at the same time, the weld formation in Example 4 is good, and no obvious defects are observed, indicating that atomic diffusion is sufficient and the interface bonding force is strong, which is beneficial for the joint to withstand external forces and thus has a higher strength. Moreover, the pictures show that the grain sizes of the heat-affected zone and the weld of the welded joint are not significantly increased compared with the base material, indicating that the heat input during the welding process is effectively controlled and the thermal damage is small.

[0084] The above content is only an example and illustration of the structure of the present invention. Those skilled in the art of this technology can make various modifications or supplements to the described specific embodiments or use similar methods to replace them, as long as they do not deviate from the structure of the invention or exceed the scope defined by this claim book, they should fall within the protection scope of the present invention.

[0085] In the description of this specification, the description with reference to terms such as "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0086] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not elaborate on all the details, nor do they limit the present invention to only the specific implementation manners. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments to better explain the principle and practical application of the present invention, so that those skilled in the art of this technology can well understand and utilize the present invention. The present invention is only limited by the claim book and its full scope and equivalents.

Claims

1. A method for preparing a mixed powder, characterized in that: The following steps are involved: Processing powder metallurgy high temperature alloy parent material FGH99 into parent material particles with a particle size of 50-90 μm; mixing the parent material particles and nickel-based powder, grinding, and obtaining a mixed powder; Wherein, in the mixed powder, the base material particles account for 1-3% by mass, and the remainder is nickel-based powder; Among them, the weight percentage of each element component in the nickel-based powder is Cr7-8%, Co9.8-10.2%, Mo2.1-2.4%, B2-2.8%, Hf0.8-1.6%, Si0.2-0.6%, W4.1-6.8%, Al3-3.5%, Ti2.3-3.1%, and the balance is nickel.

2. The method for preparing a mixed powder according to claim 1, characterized in that: The specific operation of grinding is: ball milling at a speed of 200-300 rpm for 20-40 minutes in a planetary ball mill.

3. A mixed powder intermediate layer for TLP diffusion welding, characterized in that: The mixed powder prepared by the method for preparing the mixed powder according to any one of claims 1 to 2 is mixed with a binder to form a slurry, and then dried to obtain the slurry.

4. The mixed powder intermediate layer for TLP diffusion welding according to claim 3, characterized in that: The binder is terpineol.

5. The mixed powder intermediate layer for TLP diffusion welding according to claim 3, characterized in that: The mass ratio of the mixed powder to the binder is (7-10):

1.

6. A double-spoke turbine disk TLP diffusion welding method, characterized in that: The following steps are involved: Step (1) grinding, polishing, cleaning and drying the surface of the double-spoke turbine disk workpiece to be welded to obtain a processed workpiece; Step (2) assembling the processed workpieces, applying the mixed powder intermediate layer for TLP diffusion welding described in claim 3 between the welding interfaces, and obtaining a sandwich structure of double-spoke turbine disk half disk / mixed powder intermediate layer for TLP diffusion welding / double-spoke turbine disk half disk; Step (3) placing the sandwich structure workpiece obtained in step (2) into a vacuum diffusion welding furnace, heating, heat preservation, cooling, and performing non-destructive testing to obtain a welded double-spoke turbine disk.

7. A double-spoke turbine disk TLP diffusion welding method according to claim 6, characterized in that: In step (1), the sandpaper used for polishing is 160# to 2000# sandpaper.

8. A double-spoke turbine disk TLP diffusion welding method according to claim 6, characterized in that: In the vacuum diffusion welding furnace, the heating temperature is 1090-1130° C., the pressure is 4-6 MPa, and the heat preservation is 55-65 minutes.

9. A double-spoke turbine disk TLP diffusion welding method according to claim 6, characterized in that: The heating rate during the heating process is 10°C / min.

10. A double-spoke turbine disk, characterized in that: The double-spoke turbine disk is manufactured by the TLP diffusion welding method described in claim 6.

Images