CN115194314A - Multifunctional field auxiliary manufacturing method for hollow turbine blade made of hard-to-deform material - Google Patents

Abstract

The invention provides a multifunctional field-assisted manufacturing method for hollow turbine blades made of hard-to-deform materials, which is used to solve the problems of complex process and difficult forming in the traditional method of casting hollow turbine blades. The technical points of the method include the following steps: , the first step, material preparation; the second step, electric-assisted ultrasonic consolidation forming; the third step, grinding, milling; the fourth step, stamping forming; the fifth step, hot isostatic pressing sintering; the sixth step, heat treatment , the seventh step, surface modification, get hollow turbine blade. The manufacturing method of the hollow turbine blade of the present invention simplifies the technological process, reduces the forming difficulty and reduces the processing cost.

Description

A multifunctional field-assisted manufacturing method for hollow turbine blades of refractory materials

technical field

The invention relates to the technical field of turbine blade processing, in particular to an electric-assisted ultrasonic additive manufacturing method for hollow turbine blades.

Background technique

Ultrasonic consolidation additive manufacturing technology is a new type of solid-state manufacturing process, which uses the principle of ultrasonic metal plastic processing, uses metal foil as raw material, and uses high-frequency vibration of ultrasonic waves to make the contact interface between the foil layers. Under the combined action of static pressure and high-frequency vibration, the metal atoms between the interfaces are promoted infinitely close to each other through friction, temperature rise, etc., resulting in bonding and diffusion, and solid-state metallurgical bonding between layers is realized. Compared with traditional manufacturing techniques, ultrasonic consolidation has better designability, and can manufacture complex parts with complex internal channels and cavities through the distribution and morphology design of interlayer foils. In addition, through the matching of different material foils, high-performance materials that cannot be achieved by a single material can be prepared.

Hollow turbine blades are the core components of aero-engines and gas turbines, which have far-reaching significance for national economic development and national defense security. It is difficult to manufacture due to its complex structure and high precision requirements. The process of preparing hollow turbine blades is mainly investment casting process. In the traditional method of casting hollow turbine blades, the core needs to be made first, then the wax mold of the blade is made on the surface of the core, and then the shell is formed on the surface of the wax mold of the blade by multiple coating methods, and finally, the blade is melted. The wax model of the hollow worm wheel blade was obtained. In addition, the microstructure of the cast blade is relatively coarse, the microstructure of different parts of the blade is quite different, and the material properties of the cast blade have a large dispersion and relatively low performance. This process has problems such as long manufacturing cycle, complex process and low yield.

Nickel-aluminum-based superalloys have good oxidation resistance and corrosion resistance, and can still maintain relatively high strength, creep strength and lasting strength at temperatures up to 1000 °C. However, nickel-aluminum-based alloys generally have a large friction coefficient, low thermal conductivity, small chip area, and high strength, so when they are processed, it is easy to work hardening and damage to the machining tool. It is large, requires high processing temperature and large processing cutting force, thus limiting its application. The reason why the nickel-aluminum-based superalloy is difficult to process is mainly due to the following problems: large plastic deformation, difficult to ensure accuracy, poor surface quality, serious hardening, and rapid tool wear.

After searching, it was found that the Chinese invention patent: aero-engine turbine blade hot isostatic pressing near-net shaping method, publication number: CN 113664199A, application number: 202110959791.0, the invention discloses a hot isostatic pressing net shaping method for aero-engine turbine blades: "The manufacturing method of the aero-engine turbine blade includes designing a casing; filling the casing with metal powder, and fully vibrating the metal powder until the cavity and the semi-cavity are filled with metal powder; Heating and vacuuming treatment, and then welding and sealing between the main body convex and the main body concave; the wrapping is placed in a hot isostatic pressing furnace for hot isostatic pressing densification; the wrapping is acid-corroded and removed to obtain a blade blank; The blade blank is subjected to vacuum heat treatment; the two ends of the blade blank are processed by tenon and blade crown to obtain aero-engine turbine blades." This invention uses the powder of the hard-to-deform metal alloy to manufacture the turbine blade, and forms an integral structure for the powder sintering The process is not the process of forming difficult-to-deform alloy materials from dissimilar elemental metal materials through metallurgical reactions. In addition, the method also needs to prepare metal alloy powder before processing, and it is difficult to process the blade and tenon of the alloyed turbine blade blank.

After searching, it was found that the Chinese invention patent: 3D printing turbine blade preparation method and turbine guide blade, publication number: CN110918987B, application number: 201911042078.9, the invention discloses a 3D printing turbine blade preparation method and turbine guide blade: "The The preparation method of the 3D printing turbine blade and the turbine guide blade include establishing a guide blade model through three-dimensional modeling software; importing the guide blade model into a 3D printing device, and melting nickel-based alloy powder through selective laser melting, and the particle size of the nickel-based alloy powder is 20 μm ～50μm to obtain guide vanes; heat the guide vanes for at least three times, the first heat treatment adopts a heating temperature of 1100℃～1200℃ for 2h～3h and then air cooling; the second heat treatment adopts a heating temperature of 850℃～950℃ for 7h～8h After air cooling; the third heat treatment adopts a heating temperature of 700 ° C ~ 850 ° C for 20 h ~ 30 h and then air cooling to obtain turbine guide blades." The raw material also used in this invention is alloy powder, and there is no process of forming alloy materials from foil, and the preparation The process is complicated and time-consuming. Although the subsequent heat treatment can improve the strength of the turbine guide vanes, the steps are cumbersome and energy consumption is high.

After searching, it was found that a Chinese invention patent: a preparation method of a TiAl alloy turbine blade, publication number: CN107931609 B, application number: 201711195096.1, the invention discloses a preparation method of a TiAl alloy turbine blade: "including: establishing a turbine blade The three-dimensional model is sliced to obtain slice data; the forming cavity of the electron beam selective rapid prototyping equipment is evacuated, and then the forming substrate is preheated; the TiAl alloy powder is laid on the preheated forming substrate, and then preheating is carried out. heat; perform selective melting and scanning on the preheated TiAl alloy powder to form a single-layer solid sheet; repeat steps 3 and 4 to form an electron beam selective melting forming part; after cooling, obtain a TiAl alloy turbine blade." This method is used in forming After the completion, since the vacuum chamber cannot be opened, the cooling time is quite long, which reduces the forming efficiency, and the electron beam cannot be concentrated very finely, and the forming accuracy is not high. Compared with foil consolidation, the required forming temperature is large and the conditions are harsh.

After searching, it was found that a Chinese invention patent: an integrated casting method for hollow turbine blades, publication number: CN114178484 A, application number: 202111449880.7, the invention discloses an integrated casting method for hollow turbine blades: 3D model of the casting mold; based on the 3D model of the casting mold, the green body of the casting mold is manufactured using ceramic additive manufacturing technology; the green body of the casting mold is cleaned and inspected; the green body of the casting mold is put into the heating equipment for degreasing and sintering , to obtain a mold; use a mold to cast a hollow turbine blade; wherein, the hollow turbine blade has an air film hole, the mold includes a core and a shell, and the core and the shell are connected as one piece." The invention uses a cast The method to process the turbine blade requires the design and processing of the mold, and it is troublesome to form the mold of the turbine blade with the air film holes, and the air film holes are difficult to control.

SUMMARY OF THE INVENTION

The purpose of the present invention is to simplify the process steps of the turbine blade and reduce the processing cost, and to provide a multi-functional field-assisted manufacturing method of a hollow turbine blade made of a hard-to-deform material, which integrates the material preparation and the preparation of the turbine blade.

A multifunctional field-assisted manufacturing method for hollow turbine blades made of hard-to-deform materials, comprising the following steps: a first step, material preparation; a second step, electric-assisted ultrasonic consolidation forming; a third step, milling and grinding; step, stamping forming; fifth step, hot isostatic pressing sintering; sixth step, heat treatment; seventh step, surface modification.

Further, the material preparation step is to select the foil as the raw material, first prepare the hollow foil according to the internal structure of the hollow turbine blade and the air film hole structure, then clean it to remove the surface stains, and clean the foil with acetone and alcohol in turn. .

Further, the electric-assisted ultrasonic consolidation forming step is to form dissimilar metal foils with a thickness of 0.01-0.02 mm according to A-B-A-B...A-B (taking nickel and aluminum as an example, Ni-Al-Ni-Al...Al-Ni) Sequentially (including but not limited to such dissimilar foil combinations) are sequentially consolidated together layer by layer by ultrasonic consolidation, applying a pulsed current to the foils during forming, wherein according to the hollow structure of the turbine blade and the air film holes structure, the foil material used in the middle part of the consolidation part is a hollow structure.

Further, in the milling and grinding steps, blades and tenons are processed on both ends of the plate structure component that has been ultrasonically consolidated.

Further, the stamping forming step processes the blade end of the component obtained in the previous step to a specific turbine blade shape.

Further, the hot isostatic pressing sintering step places the hollow turbine blade blank in the resistance heating furnace of the hot isostatic pressing device for processing, which promotes the diffusion of atoms between the foils, forms metal compounds, and eliminates the turbine during the ultrasonic consolidation process. The voids in the interlayer structure of the blade increase the connection between the foil interfaces.

Further, in the heat treatment step, the hot isostatic pressing parts are put into a vacuum furnace for vacuum heat treatment, so as to eliminate the interlayer interface of the foil and increase the strength of the turbine blade.

Further, in the surface modification step, the turbine blade obtained in the previous step is modified with a milling cutter to obtain a turbine blade that meets the requirements.

Further, the raw materials are nickel alloy foil and aluminum alloy foil.

Further, the ultrasonic consolidation forming process is to fix the nickel foil on the ultrasonic consolidation forming equipment and set the ultrasonic consolidation parameters, wherein the feed speed of the tool head is 10-30 mm/s, the amplitude is 20-40 μm, and the pressure is 1- 4kN; Consolidate the aluminum foil on the nickel foil and set the parameters of ultrasonic consolidation, in which the feed speed of the tool head is 10-30mm/s, the amplitude is 15-30μm, and the pressure is 0.5-3kN.

Further, a pulse current is applied to the foil during the consolidation process, the pulse current range is 1200-4000A, the frequency is 150-500Hz, and the pulse width is 50-80μs.

Further, in the process of hot isostatic pressing, the equal pressure in all directions is not less than 150MPa, the temperature is 1100°C to 1400°C, and the holding time is 2h to 4h.

Further, the heating temperature in the heat treatment process is 1100°C to 1400°C, the holding time is 2h, and the vacuum furnace is cooled.

Advantages of the present invention:

1. A multi-functional field-assisted manufacturing method for hollow turbine blades made of difficult-to-deform materials of the present invention integrates material preparation and blade manufacturing, and compared with traditional processes, the machining volume is small, the internal defects are few, and the process is controllable. High, fewer process steps, lower production costs.

2. The multi-functional field-assisted manufacturing method of a hollow turbine blade made of a refractory material of the present invention, the plate-layer structure formed by ultrasonic consolidation forms a connection between the foil layers, and retains the original nickel and aluminum. The advantages of low strength and high plasticity. Before hot isostatic pressing sintering to form a nickel-aluminum-based superalloy, the blank is processed for the topography of the blade, which greatly reduces the processing difficulty.

3. A multi-functional field-assisted manufacturing method for hollow turbine blades made of hard-to-deform materials of the present invention, through the specific superposition and consolidation of hollow foil materials, the hollow turbine blade structure is formed without the need for cavity design of the mold, which reduces the number of processes. step, reduce the processing cost, and have high controllability.

4. A multifunctional field-assisted manufacturing method of a hollow turbine blade made of a hard-to-deform material of the present invention uses a metal foil as a raw material, and does not require alloy powder manufacturing.

Description of drawings

The accompanying drawings are provided for a further understanding of the present invention.

FIG. 1 is a flow chart of the manufacturing method of the hollow turbine blade provided by the present invention.

Figure 2 is a schematic diagram of two solid foils formed by ultrasonic consolidation.

FIG. 3 is a schematic diagram of a foil with a hollow structure in the middle of a hollow turbine blade formed by ultrasonic consolidation.

Figure 4 is a schematic diagram of foil stacking.

FIG. 5 is a schematic diagram of the layer structure of the electrically assisted ultrasonic consolidation forming.

FIG. 6 is a schematic diagram of a turbine blade with a laminate structure.

FIG. 7 is a schematic diagram of a finished turbine blade.

In the picture: 1. Air membrane hole, 2. Hollow structure

Detailed ways

In order to make the present invention easier to understand clearly, the technical solutions of the present invention are described in detail below with reference to the accompanying drawings.

As shown in FIG. 1 , a multifunctional field-assisted manufacturing method for hollow turbine blades made of hard-to-deform materials includes the following steps. The first step is material preparation. Taking nickel-aluminum-based superalloy turbine blades as an example, the material preparation steps are to select nickel foil and aluminum foil as raw materials. First, prepare two kinds of solid nickel and aluminum foils 3 and 4 shown in FIG. 2 ; prepare hollow nickel and aluminum foils 5 ( FIG. 3 ) according to the internal structure of the hollow turbine blade and the air film hole structure. It is then cleaned to remove surface stains and the foil is cleaned with acetone and then alcohol.

The second step is electric-assisted ultrasonic consolidation molding. The electric-assisted ultrasonic consolidation forming step is to consolidate the foils with a thickness of 0.01 to 0.02 mm in the order of Ni-Al-Ni-Al...Al-Ni by ultrasonic consolidation method layer by layer, wherein First, the foil 3 is consolidated, then the hollow foil 5 is consolidated on the stack, the foil 3 is consolidated on the stack, and finally the foil 4 is consolidated on the upper and lower surfaces of the stack, as shown in Figure 4 . Fix the nickel foil on the ultrasonic consolidation forming equipment and set the parameters of ultrasonic consolidation. The feed speed of the tool head is 10-30 mm/s, the amplitude is 20-40 μm, and the pressure is 1-4 kN; the aluminum foil is consolidated on the nickel foil and set For ultrasonic consolidation parameters, the feed speed of the tool head is 10-30 mm/s, the amplitude is 15-30 μm, and the pressure is 0.5-3 kN. During the forming process, a pulse current is applied to the foil. The pulse current range is 1200-4000A, the frequency is 150-500Hz, and the pulse width is 60-80μs.

The third step is milling and grinding. In the milling and grinding steps, blade processing is performed on the thin end of the laminate structure component (FIG. 5) obtained in the second step, and tenon processing is performed on the thick end.

The fourth step is stamping. The stamping step machines the blade ends of the part obtained in the third step to a specific turbine blade shape (Figure 6).

The fifth step is hot isostatic pressing. The hot isostatic pressing step is to place the turbine blade blank in the resistance heating furnace of the hot isostatic pressing device for processing, which promotes the diffusion of atoms between the foils, forms metal compounds, and eliminates the interlayer of the turbine blade during the ultrasonic consolidation process. The voids in the structure increase the connection between the foil interfaces. In the process of hot isostatic pressing, the equal pressure in all directions is not less than 150Mpa, the temperature is 1100℃～1400℃, and the holding time is 2h～4h.

The sixth step is heat treatment. In the heat treatment step, the hot isostatic pressing parts are put into a vacuum furnace for vacuum heat treatment, so as to eliminate the interlayer interface of the foil and increase the strength of the turbine blade. The temperature of the vacuum heat treatment is 1100℃～1400℃, the holding time is 2h, and finally it is cooled in a vacuum furnace.

The seventh step is surface modification. In the surface modification step, the turbine blade obtained in the previous step is modified with a milling cutter to obtain a turbine blade that meets the requirements.

Claims (15)

1. a multi-energy field-assisted manufacturing method of a hollow turbine blade of a difficult-to-deform material, is characterized in that: comprising the steps, the first step, material preparation; the second step, the electric-assisted ultrasonic consolidation forming; the third step, milling , grinding; fourth step, stamping forming; fifth step, hot isostatic pressing sintering; sixth step, heat treatment; seventh step, surface modification. 2. The multifunctional field-assisted manufacturing method of a hollow turbine blade of a hard-to-deform material as claimed in claim 1, wherein the material preparation step selects a foil as a raw material, and firstly according to the internal structure of the hollow turbine blade and the air film hole The hollowed-out foil was prepared by the structure, and then cleaned to remove the surface stains, and the foil was cleaned with acetone and alcohol in turn. 3 . The multifunctional field-assisted manufacturing method of a hollow turbine blade made of a hard-to-deform material as claimed in claim 1 , wherein in the step of electric-assisted ultrasonic consolidation and forming, dissimilar metal foils with a thickness of 0.01 to 0.02 mm are formed. 4 . According to the sequence of A-B-A-B...A-B (taking nickel and aluminum as an example, Ni-Al-Ni-Al...Al-Ni) (including but not limited to this kind of dissimilar foil combination), ultrasonic consolidation method is used layer by layer sequentially When they are consolidated together, a pulse current is applied to the foil during the forming process. According to the hollow structure of the turbine blade and the air film hole structure, the foil used in the middle part of the lamination consolidation process is a hollow structure. 4. The multi-functional field-assisted manufacturing method of a hollow turbine blade made of a hard-to-deform material as claimed in claim 1, wherein the milling and grinding step carry out the blade operation on both ends of the sheet structure component that is ultrasonically consolidated. and tenon processing. 5. The multifunctional field-assisted manufacturing method of a hollow turbine blade of a hard-to-deform material as claimed in claim 1, wherein the stamping forming step processes the blade end of the formed part obtained in the previous step, to a specific turbine blade. Leaf shape. 6. The multifunctional field-assisted manufacturing method of a hollow turbine blade of a hard-to-deform material as claimed in claim 1, wherein the hot isostatic pressing sintering step places the turbine blade blank in the resistance heating of the hot isostatic pressing device Treatment in the furnace promotes the diffusion of atoms between foils, forms intermetallic compounds, and eliminates voids in the interlayer structure of turbine blades, increasing the connection between foil interfaces. 7. the multifunctional field-assisted manufacturing method of the hollow turbine blade of a kind of difficult-to-deform material as claimed in claim 1, is characterized in that: the heat treatment step puts the hot isostatic pressing finished part into the vacuum furnace to carry out vacuum heat treatment, To eliminate the interlayer interface of the foil, increase the strength of the turbine blade. 8. the multifunctional field-assisted manufacturing method of the hollow turbine blade of a kind of refractory material as claimed in claim 1, is characterized in that: the surface modification step carries out modification to the turbine blade obtained in the previous step with a milling cutter, and obtains a required turbine blades. 9. The multifunctional field-assisted manufacturing method of a hollow turbine blade of a kind of refractory material as claimed in claim 2, wherein the material is the original composition single element foil of refractory alloy material (with nickel-aluminum-based superalloy Nickel foil and aluminum foil for example). 10. The multi-functional field-assisted manufacturing method of a hollow turbine blade made of a hard-to-deform material as claimed in claim 3, wherein: the ultrasonic consolidation forming fixes the nickel foil on the ultrasonic consolidation forming equipment and sets the process parameters, and the tool The feeding speed of the head is 10-30 mm/s, the amplitude is 20-40 μm, and the pressure is 1-4 kN; the ultrasonic consolidation parameters are set for consolidating the aluminum foil on the nickel foil, and the feeding speed of the tool head is 10-30 mm/s, and the amplitude is 15～30μm, the pressure is 0.5～3kN. 11. The multi-functional field-assisted manufacturing method for a hollow turbine blade made of a refractory material as claimed in claim 3, wherein a pulse current is applied to the foil during the consolidation process, and the pulse current ranges from 1200 to 4000 A, and the frequency is 1200-4000A. It is 150～500Hz, and the pulse width is 50～80μs. 12 . The multi-functional field-assisted manufacturing method of a hollow turbine blade made of a hard-to-deform material as claimed in claim 5 , wherein in the hot isostatic pressing sintering step, the equal pressure in each direction is not less than 150 MPa, and the temperature is 1100 ℃～ 1400 ℃, the holding time is 2h ~ 4h. 13 . The multi-functional field-assisted manufacturing method for hollow turbine blades made of hard-to-deform materials according to claim 6 , wherein the heating temperature of the heat treatment is 1100°C to 1400°C, the holding time is 2 hours, and the vacuum furnace is cooled. 14 . 14. The multi-functional field-assisted manufacturing method of a hollow turbine blade made of a hard-to-deform material according to claims 1 to 3, wherein the hollow structure and the air film hole structure of the hollow turbine blade are made of hollow foil material according to a certain It is obtained by sequential stacking and consolidation, with high controllability, no need for mold cavity design, reducing process steps and reducing processing costs. 15. The multi-functional field-assisted manufacturing method for a hollow turbine blade made of a refractory material as claimed in claims 4 to 7, characterized in that: forming a laminated foil structure by means of electric-assisted ultrasonic consolidation, which has a certain The overall structure of the connection strength retains the characteristics of high plasticity and low deformation resistance of the original foil; the processing of the laminated structure of the foil can smoothly form the complex structure and shape of the blade, which greatly reduces the high temperature resistance and difficult deformation. Afterwards, atomic diffusion and metallurgical bonding between foils are realized by hot isostatic pressing to form intermetallic compounds (such as NiAl), and the preparation of difficult-to-deform materials can be realized while forming complex blade structure shapes.

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