A method for manufacturing thin-walled intermetallic compound parts

Abstract

This invention belongs to the field of metal thin-walled component manufacturing, and relates to a method for manufacturing intermetallic compound thin-walled components. First, Al and Ti pure metal foils are alternately stacked and then hot-rolled to prepare an Al / Ti pure metal composite thin plate. Next, a progressive forming process is used to shape the composite thin plate into a thin-walled component. Then, a 50-200A current is used to locally heat the material under self-resistance heating, combined with pressure applied by tools, causing a diffusion reaction between the pure Al and Ti metals in the composite thin plate under high temperature and pressure. This transforms the component material from pure metal to a TiAl intermetallic compound, thus realizing the preparation of a TiAl intermetallic compound thin-walled component. This method utilizes the high plasticity and low strength characteristics of the metal foil composite thin plate to achieve rapid and low-cost manufacturing of thin-walled components. Precise control of pressure and temperature during the self-resistance heating process ensures uniform and controllable material diffusion reaction, thereby transforming the pure metal composite thin plate into a high-strength and heat-resistant TiAl intermetallic compound.

Description

Technical Field

[0001] This invention belongs to the field of metal thin-walled parts manufacturing, and specifically relates to a method for manufacturing intermetallic compound thin-walled parts. Background Technology

[0002] Aircraft design typically employs materials with low density and high modulus to reduce structural weight and improve flight performance. With technological advancements, the surface temperature of thin-walled outer skin components in supersonic and aerospace vehicles can reach 800°C during operation. TiAl intermetallic compounds possess significantly higher high-temperature resistance and strength than aluminum alloys, and superior elastic modulus and density compared to titanium alloys, with a temperature resistance reaching 850°C, making them an excellent candidate material for thin-walled components in high-speed aircraft. However, the high strength and poor plasticity of intermetallic compounds make the preparation and forming of thin-walled component blanks difficult, limiting their application. Summary of the Invention

[0003] The purpose of this invention is to propose a method for manufacturing thin-walled intermetallic compound parts, in order to solve the problems of difficult forming, long production cycle, and high cost of TiAl intermetallic compound thin-walled parts with a thickness of less than 3mm.

[0004] To solve this technical problem, the technical solution of the present invention is as follows:

[0005] A method for manufacturing thin-walled intermetallic compound parts includes the following processing steps:

[0006] First, pure Al and pure Ti metal foils with a thickness of 0.05–0.3 mm are alternately stacked and then hot-rolled to prepare Al and Ti pure metal composite thin plates. Then, the composite thin plates are shaped into thin-walled parts using a progressive forming process. Next, the material is locally heated by self-resistance using a current of 50–200 A, combined with a pressure of 100–1000 N applied by an insulated tool, causing the pure metals Al and Ti in the composite thin plates to undergo a diffusion reaction under high temperature and high pressure, transforming the part material from pure metal to TiAl intermetallic compound, thereby realizing the preparation of TiAl intermetallic compound thin-walled parts.

[0007] In high temperature and high pressure environments, the temperature range is 900–1200℃, and the pressure range is 35–64 MPa; the pressure (P) of insulating tools can be measured by... The result is given by: where F is the pressure applied by the insulating tool, α is the part forming angle, R is the radius of the insulating tool, and the contact area S = π(R) 2 -(RF 0.4 / 100) 2 ).temperature Where I is the current and t is the thickness of the metal composite sheet.

[0008] When pure metals Al and Ti undergo a diffusion reaction under high temperature and pressure, excessively high temperatures and pressures can cause Al to dissipate due to the difference in strength and melting point between Al and Ti. Conversely, excessively low temperatures can lead to incomplete diffusion. Therefore, the diffusion temperature needs to be controlled between 900 and 1200°C. Insufficient pressure can also cause defects such as voids and porosity in the Al layer due to atomic movement. Therefore, the combination of temperature and pressure parameters is typically controlled within a certain range during the process.

[0009] Al and Ti pure metal composite sheets have a tensile strength of 215 MPa and an elongation of 30%, while TiAl intermetallic compounds have a tensile strength exceeding 1200 MPa and an elongation of only 0.3–4%, making them difficult to form and resulting in significant springback after forming due to their high strength. In the aforementioned process, the low strength and high plasticity of pure metal composite sheets are utilized to achieve rapid and low-cost forming of thin-walled parts with a thickness of less than 3 mm without molds through incremental forming. Furthermore, for the formed parts, Al and Ti atoms undergo dispersion migration under in-situ localized thermal coupling, diffusing between the pure metal layers, thus transforming the pure metal layers into an alloy layer composed of Al and Ti, forming the TiAl intermetallic compound. Compared to direct forming of TiAl intermetallic compounds, this process solves the technical difficulties of forming TiAl intermetallic compounds due to their poor plasticity, reduces springback deformation of thin-walled parts, and minimizes energy consumption associated with forming high-strength materials.

[0010] Specifically, the method of the present invention includes the following processing steps:

[0011] Step 1: Alternately stack pure aluminum and pure titanium foils to form a billet with a foil thickness of 0.05–0.3 mm; set the rolling parameters: initial billet temperature 450–530℃, roll diameter 200–600 mm, rolling speed 2–5 m / min; roll the billet into a composite sheet; the composite sheet thickness is less than 3 mm.

[0012] In order to bond pure aluminum and pure titanium together through rolling, and to avoid excessively high temperatures that could cause the pure aluminum layer to be extruded or to form hard and brittle impurity phases at the interface, the initial temperature of the billet is set within this range: 450–530℃.

[0013] Step 2: Select the diameter of the forming tool according to the material thickness, generate the forming trajectory based on the shape of the part, cover the upper and lower sides of the composite thin plate with pads, and prepare the part shape by progressive forming of the composite thin plate; the pads are used to seal the composite thin plate, which can prevent the forming tool from directly contacting the material and scratching the surface of the part, and can also prevent the material from oxidizing during subsequent heating.

[0014] The diameter of the forming tool ranges from 10 to 30 mm. The relationship between the tool diameter and the material thickness is: D / t≥10, where D is the diameter of the forming tool.

[0015] The progressive forming process parameters are set as follows: the trajectory line spacing range is 0.1 to 1.5 mm, and the forming speed is 1000 to 5000 mm / min;

[0016] Step 3: Replace the force-controlled insulating tool, set the line spacing, feed speed, and trajectory repetition count, and set the insulating tool's pressing force and current parameters. Connect the insulating tool to the DC power supply and make it contact the pad. The current passes through the composite thin plate to form a current loop and generates heat due to the composite thin plate's own resistance. The composite thin plate heats up to a high temperature of 900-1200℃ through its self-resistance heating, and pressure is applied through the insulating tool, causing the composite thin plate to form an intermetallic compound under high temperature and high pressure.

[0017] The parameters in step three are set as follows: the line spacing is 0.1 to 1 mm, the feed speed is 100 to 1000 mm / min, the number of trajectory repetitions is 2 to 10, the insulated tool pressing force is 100 to 1000 N, and the current is 50 to 200 A.

[0018] The diffusion effect is related to high temperature and pressure, as well as the duration of action. In the high temperature and pressure range, the temperature range is 900–1200℃, and the pressure range is 35–64 MPa. The pressure is mainly related to the applied pressure (F) of the insulating tool, the forming angle (α) of the part, and the contact area (S). The relationship between pressure and force is P = Fcosα / S. The contact area S is related to the pressure (F) and the radius (R) of the insulating tool, i.e., S = π(R / F). 2 -(RF 0.4 / 100) 2 Under conditions where the tool head diameter ranges from 20 to 30 mm and the forming angle from 0 to 45°, based on the relationship between pressure and force, the insulating tool pressing force ranges from 100 to 1000 N; temperature is related to current (I), the thickness (t) of the composite sheet, and the contact area (S), based on the relationship formula. The current range is 50–200A. Heating time is related to the contact area S, row spacing L, feed speed v, and the number of trajectory repetitions N. To ensure effective diffusion, the contact time t c >1s, therefore, the line spacing range is 0.1 to 1mm, the feed speed range is 100 to 1000mm / min, and the trajectory repetition number is 2 to 10 times.

[0019] The backing plate is made of steel plate with a thickness of 0.5 to 1.0 mm. Using steel plate as the material for the backing plate is problematic. If the backing plate is too thick, excessive deformation resistance will cause the composite sheet to break under pressure; if the backing plate is too thin, it will break during the forming process. Therefore, for forming composite sheets less than 3 mm thick, the backing plate thickness is typically chosen to be 0.5 to 1.0 mm.

[0020] The force-controlled insulating tool achieves insulation between itself and equipment such as double-sided CNC progressive forming equipment or dual-robot systems through a ceramic bushing on the tool holder.

[0021] The force-controlled insulating tools are of the fixed ball or rolling disc type, with a tool head diameter ranging from 20 to 30 mm, and are made of cemented carbide.

[0022] The force control methods in the force-controlled insulating tool include pneumatic systems, hydraulic systems, and electric actuators.

[0023] In step two, the backing plates are placed on both sides of the composite sheet. Graphite is applied between the composite sheet and the backing plates to prevent them from spreading and bonding together, while maintaining conductivity between them to meet the self-resistance heating requirements of the material. The edges of the two backing plates need to be welded together, and the air between the backing plates is evacuated to create a vacuum environment of 0.001–0.0001 MPa. By placing the backing plates, the composite sheet is kept in a vacuum state during the self-resistance heating process, avoiding high-temperature oxidation. Furthermore, during the progressive forming process, the forming tool is prevented from directly contacting the composite sheet, thus avoiding scratches on the composite sheet surface.

[0024] Before stacking the foil in step one, it is necessary to clean the surface stains and then use nitric acid solution to corrode the material to passivate the surface.

[0025] The forming tool in step two is made of cemented carbide or bearing steel.

[0026] In step two, the incremental forming equipment adopts a double-sided CNC incremental forming equipment or a dual-robot system.

[0027] The purity of the Al and Ti pure metal foil is above 99.99%.

[0028] In step three, the DC power supply is a safe voltage of 36V.

[0029] In particular, the thickness of the intermetallic compound thin-walled part prepared by the method of the present invention is less than 3 mm.

[0030] The beneficial effects of this invention are:

[0031] 1. Intermetallic compound materials have high strength but poor formability, while pure metal materials have excellent forming limits but lower strength compared to alloys. This invention avoids the problems of difficult forming and high deformation resistance of intermetallic compounds by first forming a pure metal layered composite sheet and then forming a TiAl intermetallic compound under high temperature and pressure, effectively reducing the energy consumption and mold wear caused by the forming of intermetallic compounds.

[0032] 2. This invention achieves flexible forming of complex shapes of parts and in-situ preparation of TiAl intermetallic compounds through progressive forming equipment. Compared with traditional mold forming methods, it can effectively reduce the cost and cycle of mold manufacturing.

[0033] 3. In the forming process, the present invention covers the material surface with a pad, applies graphite between the material and the pad, and forms a vacuum environment through the pad. This can prevent the oxidation of the material surface when the pure metal layered composite thin plate forms TiAl intermetallic compound under high temperature and pressure. Attached Figure Description

[0034] Figure 1 This is a process flow diagram of the intermetallic compound thin-walled part manufacturing method of the present invention;

[0035] Figure 2 This is a schematic diagram of the composite thin plate stacking in this invention;

[0036] Figure 3 This is a schematic diagram of the composite sheet rolling process of the present invention;

[0037] Figure 4 This is a schematic diagram showing the placement of the composite thin plate pad of the present invention;

[0038] Figure 5 This is a schematic diagram of the progressive forming process of the present invention;

[0039] Figure 6 This is a schematic diagram of in-situ localized heating using a fixed spherical insulating tool;

[0040] Figure 7 This is a schematic diagram of the formation of TiAl intermetallic compounds in this invention;

[0041] Figure 8 The microstructure of the composite thin plate in Example 1;

[0042] Figure 9 This is a physical image of the part prepared in Example 1;

[0043] Figure 10 The microstructure of the composite sheet is loose due to insufficient pressure in Example 1;

[0044] Figure 11These are the scanned tissue and EDS results of the incompletely diffused composite thin plate in Example 1, where the left image shows the tissue and the right image shows the EDS result;

[0045] Figure 12 It is the microstructure of the fully diffused composite thin plate in Example 1;

[0046] Figure 13 This is a schematic diagram of in-situ localized heating using a rolling disc-type insulating tool.

[0047] Among them, 1. pure aluminum foil; 2. pure titanium foil; 3. rolling mill rolls; 4. composite sheet; 5. pad; 6. pressure ring; 7. progressive forming tool head; 8. insulating fixed ball tool; 9. DC power supply; 10. TiAl intermetallic compound sheet; 11. insulating rolling disc tool. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0049] The features of various aspects of the embodiments of the present invention will now be described in detail. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention can also be practiced without these specific details. The following description of the embodiments is merely intended to provide a better understanding of the invention by illustrating examples. The invention is not limited to any specific setups and methods provided below, but covers all improvements, substitutions, etc., to product structures and methods without departing from the spirit of the invention.

[0050] In the various accompanying drawings and the following description, well-known structures and techniques are not shown in order to avoid unnecessarily obscuring the invention.

[0051] A method for manufacturing an intermetallic compound thin-walled part according to the present invention will now be described in detail with reference to the accompanying drawings.

[0052] Figure 1 This is a flowchart of a method for manufacturing thin-walled intermetallic compound parts disclosed in this invention. (Combined with...) Figure 2-7 The preparation method of the present invention includes the following steps:

[0053] S100 alternately stacks pure aluminum and pure titanium foil of a certain thickness, sets rolling parameters such as initial billet temperature, roll diameter, and rolling speed, and produces composite thin plates by high-temperature rolling.

[0054] In step S100, the thickness of the foil is 0.05 to 0.3 mm. Before stacking the foil, the surface stains need to be cleaned, and then the material is corroded with nitric acid solution to passivate the material surface.

[0055] In step S100, the initial temperature of the billet is in the range of 450 to 530°C, the diameter of the roll is in the range of 200 to 600 mm, and the rolling speed is in the range of 2 to 5 m / min.

[0056] The S200 designs progressive forming process parameters such as forming tool diameter, trajectory line spacing, and forming speed based on the part shape, and generates forming trajectory. The composite thin plate is covered with pads on both the top and bottom. On a double-sided CNC progressive forming special equipment or a dual robot system, the composite thin plate is made into part shape through progressive forming.

[0057] In step S200, the forming tool is made of cemented carbide or bearing steel, with a diameter ranging from 10 to 30 mm, a track spacing ranging from 0.1 to 1.5 mm, and a forming speed ranging from 1000 to 5000 mm / min.

[0058] In step S200, the cover plate is generally a steel plate with good formability and low price, with a thickness of 0.5 to 1.0 mm. The cover plate is placed on both sides of the composite thin plate. Graphite is applied between the steel plate and the cover plate and then welded together while maintaining conductivity. The edges of the two cover plates need to be welded together and the air between the cover plates is extracted to form a vacuum environment of 0.001 to 0.0001 MPa.

[0059] The S300 replaces the force-controlled insulating tool, sets trajectory parameters such as line spacing, feed speed, and trajectory repetition count, sets the insulating tool's pressing force and current parameters, connects the insulating tool to a 36V DC power supply and partially contacts the sheet metal, and uses the high temperature generated by self-resistance heating and the pressure applied by the tool to form an intermetallic compound in the part material under high temperature and high pressure.

[0060] In step S300, the tool holder of the force-controlled insulating tool is insulated from the double-sided CNC progressive forming special equipment or dual robot system through a ceramic bushing. The tool type is fixed ball or rolling disc, the tool head diameter ranges from 20 to 30 mm, the material is cemented carbide, and the force control forms include pneumatic system, hydraulic system and electric push rod control methods.

[0061] In step S300, the line spacing ranges from 0.1 to 1 mm, the feed speed ranges from 500 to 3000 mm / min, the number of trajectory repetitions is 2 to 10 times, the insulated tool pressing force ranges from 100 to 1000 N, and the current ranges from 50 to 200 A.

[0062] The following is in conjunction with the appendix Figures 8-12 The method for preparing thin-walled intermetallic compound parts of different thicknesses is further explained.

[0063] Example 1

[0064] Step 1: After rinsing 6 layers of 0.2mm thick pure aluminum foil and 5 layers of 0.2mm thick pure titanium foil with clean water, the surfaces are etched using a 0.1% nitric acid solution. The pure aluminum and pure titanium foils are then alternately stacked together to form a 2.2mm thick composite sheet. The composite sheet is heated to 530℃ and rolled to 1.1mm using a 300mm diameter rolling mill at a rolling speed of 3m / min. The microstructure of the composite sheet is as follows... Figure 8 As shown.

[0065] Step 2: Generate a forming trajectory based on the part shape, where the forming tool diameter is 30mm, the trajectory line spacing is 1.5mm, and the forming speed is set to 5000mm / min. Before forming, graphite is coated on both sides of the composite sheet. Experiments showed that if the backing plate is too thick, the composite sheet will be crushed due to excessive deformation resistance; if the backing plate is too thin, it will break during the forming process. DC04 deep-drawing steel plates with thicknesses of 0.5mm and 1.0mm can meet the experimental requirements. In this experiment, a 0.5mm thick DC04 deep-drawing steel plate was selected as the backing plate to cover both sides of the composite sheet.

[0066] The edges of the steel plates are welded together, and the air between the plates is evacuated to 0.001 MPa using a vacuum pump. The welded plates are then placed on a progressive forming machine and secured with a blank holder. Forming tests are then conducted, shaping the plates to the designed shape using forming tools. The resulting part has the following shape: Figure 9 As shown.

[0067] Step 3: Replace with a 20mm diameter pneumatically controlled insulated fixed spherical tool to generate a forming trajectory based on the part shape, with a trajectory row spacing of 1.0mm. When the tool pressure is too low, the Al layer may develop defects such as voids and porosity due to atomic movement, as shown in the image. Figure 10 As shown; however, when the current is too low, resulting in a low temperature, or the contact time is too short, diffusion will be insufficient, and the original pure aluminum layer will form Al3Ti, with some Ti remaining, such as... Figure 11As shown. Therefore, the tool pressing force is selected as 100N, the DC power supply voltage is 36V, the current is 50A, the feed speed is set to 1000mm / min, and the trajectory repetition count is 5 times.

[0068] The part material is a homogeneous TiAl intermetallic compound, and the cross-sectional microstructure is as follows: Figure 12 As shown, the material's strength reaches 1230 MPa, which is much higher than the 420 MPa of pure metallic Ti and the 65 MPa of pure Al, significantly improving the material's strength.

[0069] Example 2

[0070] Step 1: After rinsing 10 layers of 0.1mm thick pure aluminum foil and 9 layers of 0.08mm thick pure titanium foil with clean water, the surfaces are etched using a 0.1% nitric acid solution. The pure aluminum and pure titanium foils are then stacked alternately to form a 1.72mm thick composite sheet. The composite sheet is heated to 530℃ and rolled to 1.0mm using a 300mm diameter rolling mill at a rolling speed of 3m / min.

[0071] Step 2: Generate a forming trajectory based on the part shape, where the forming tool diameter is 30mm, the trajectory line spacing is 1.5mm, and the forming speed is set to 5000mm / min. Before forming, graphite is coated on both sides of the composite sheet, and then two 0.5mm thick DC04 deep-drawing steel plates are placed on both sides of the composite sheet. The edges of the steel plates are welded together, and the air between the steel plates is evacuated to 0.001MPa using a vacuum pump. The welded sheet is placed on a progressive forming machine and fixed with a blank holder. Forming tests are then conducted, and the sheet is formed into the designed shape using the forming tool.

[0072] Step 3: Replace with a 20mm diameter pneumatically controlled insulated fixed ball tool, generate a forming trajectory based on the part shape, with a trajectory line spacing of 1.0mm, a tool pressing force of 100N, a DC power supply voltage of 36V, a current of 50A, a feed speed of 1000mm / min, and a trajectory repetition count of 5 times.

[0073] Example 3

[0074] Step 1: Rinse 20 layers of 0.05mm thick pure aluminum foil and 19 layers of 0.05mm thick pure titanium foil with clean water, then etch the surface with a 0.1% nitric acid solution. Alternately stack the pure aluminum and pure titanium foils together to form a 1.95mm thick composite sheet. Heat the composite sheet to 500℃ and roll it to 1.5mm using a 250mm diameter rolling mill at a rolling speed of 2m / min.

[0075] Step 2: Generate a forming trajectory based on the part shape, where the forming tool diameter is 10mm, the trajectory line spacing is 0.1mm, and the forming speed is set to 3000mm / min. Before forming, graphite is coated on both sides of the composite sheet, and then two 1mm thick DC04 deep-drawing steel plates are placed on both sides of the composite sheet. The edges of the steel plates are welded together, and the air between the steel plates is evacuated to 0.0001MPa using a vacuum pump. The welded sheet is placed on a progressive forming machine and fixed with a blank holder. The forming test then begins, shaping the sheet to the designed shape using the forming tool.

[0076] Step 3: Replace with a 30mm diameter hydraulically controlled insulated rolling disc tool, generate a forming trajectory based on the part shape, with a trajectory line spacing of 0.3mm, a tool pressing force of 500N, a pulsed DC power supply voltage of 36V, a current of 120A, a feed speed of 500mm / min, and a trajectory repetition count of 10 times.

[0077] Example 4

[0078] Step 1: After rinsing 10 layers of 0.3mm thick pure aluminum foil and 10 layers of 0.3mm thick pure titanium foil with clean water, etch the surface with a 0.1% nitric acid solution. Alternately stack the pure aluminum and pure titanium foils together to form a 6.0mm thick composite sheet. Heat the composite sheet to 450℃ and roll it to 3.0mm using a 600mm diameter rolling mill at a rolling speed of 5m / min.

[0079] Step 2: Generate a forming trajectory based on the part shape, where the forming tool diameter is 30mm, the trajectory line spacing is 0.5mm, and the forming speed is set to 1000mm / min. Before forming, graphite is coated on both sides of the composite sheet, and then two 0.5mm thick DC06 deep-drawing steel plates are placed on both sides of the composite sheet. The edges of the steel plates are welded together, and the air between the steel plates is evacuated to 0.001MPa using a vacuum pump. The welded sheet is placed on a progressive forming machine and fixed with a blank holder. Forming tests are then conducted, shaping the sheet to the designed shape using the forming tool.

[0080] Step 3: Replace with a 30mm diameter electrically controlled insulated fixed ball, generate a forming trajectory based on the part shape, with a trajectory line spacing of 0.1mm, a tool pressing force of 1000N, a DC power supply voltage of 36V, a current of 200A, a feed speed of 100mm / min, and a trajectory repetition count of 2.

[0081] All the above-mentioned optional technical solutions can be combined in any way to form the optional embodiments of this application, and will not be described in detail here. It should be understood that the sequence number of each step in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0082] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should be covered within the protection scope of the present invention.

Claims

1. A method for manufacturing thin-walled intermetallic compound parts, characterized in that: The method described is applicable to the forming of TiAl intermetallic compound thin-walled parts with a thickness of less than 3 mm. First, pure Al and pure Ti metal foils with a thickness of 0.05~0.3 mm are alternately stacked and then hot-rolled to prepare an Al and Ti pure metal composite thin plate. Then, the composite thin plate is formed into the shape of a thin-walled part through a progressive forming process. Next, a 50~200 A current is used to locally heat the material with self-resistance, and combined with a pressure of 100~1000 N applied by an insulated tool, so that the pure metals Al and Ti in the composite thin plate undergo a diffusion reaction under high temperature and high pressure, transforming the material of the part from pure metal to TiAl intermetallic compound, thereby realizing the preparation of TiAl intermetallic compound thin-walled parts. In the high temperature and high pressure environment, the temperature range is 900~1200℃ and the pressure range is 35~64MPa; The method includes the following processing steps: Step 1: Alternately stack pure aluminum and pure titanium foils to form a billet with a foil thickness of 0.05~0.3 mm; set the rolling parameters: initial billet temperature 450~530 ℃, roll diameter 200~600 mm, rolling speed 2~5 m / min; roll the billet into a composite sheet; the composite sheet thickness is less than 3 mm. Step 2: Select the forming tool diameter based on the material thickness, generate the forming trajectory based on the part shape, cover the upper and lower sides of the composite thin plate with pads, and prepare the part shape by progressive forming of the composite thin plate; the pads are used to seal the composite thin plate; The diameter of the forming tool ranges from 10 to 30 mm. The relationship between the tool diameter and the material thickness is: D / t≥10, where D is the diameter of the forming tool. The incremental forming process parameters are: the trajectory line spacing range is 0.1~1.5 mm, and the forming speed is 1000~5000 mm / min; Step 3: Replace the force-controlled insulating tool, set the line spacing, feed speed, and trajectory repetition count. Set the insulating tool's pressing force and current parameters. Connect the insulating tool to the DC power supply and make it contact the pad. The current passes through the composite thin plate to form a current loop and generates heat due to the composite thin plate's own resistance. The composite thin plate's self-resistance heats up to a high temperature, and the insulating tool applies pressure, causing the composite thin plate to form an intermetallic compound under high temperature and high pressure.

2. The method according to claim 1, characterized in that: The parameters in step three are set as follows: line spacing range is 0.1~1 mm, feed speed range is 100~1000 mm / min, trajectory repetition number is 2~10 times, insulated tool pressing force range is 100~1000 N, and current range is 50~200 A.

3. The method according to claim 1, characterized in that: In step two, the backing plate is a steel plate with a thickness of 0.5~1.0 mm.

4. The method according to claim 1, characterized in that: In step two, the pads are placed on both sides of the composite sheet. Graphite is applied between the composite sheet and the pads to prevent them from spreading and connecting together, while maintaining the conductivity between them to meet the self-resistance heating requirement of the material. The edges of the two pads need to be welded together and the air between the pads needs to be removed to form a vacuum environment of 0.001~0.0001 MPa.

5. The method according to claim 1, characterized in that: The force-controlled insulating tools are of the fixed ball or rolling disc type, with a tool head diameter ranging from 20 to 30 mm, and are made of cemented carbide.

6. The method according to claim 1, characterized in that: Force control methods in force-controlled insulating tools include pneumatic systems, hydraulic systems, and electric actuator control.

7. The method according to claim 1, characterized in that: Before stacking the foil in step one, it is necessary to clean the surface stains and then use nitric acid solution to corrode the material to passivate the surface.

8. The method according to claim 1, characterized in that: The forming tool in step two is made of cemented carbide or bearing steel.

9. The method according to claim 1, characterized in that: In step two, the incremental forming equipment adopts a double-sided CNC incremental forming equipment or a dual-robot system.

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