A method for multi-channel curved surface structure superplastic forming / diffusion bonding

Abstract

The application discloses a kind of multi-channel curved surface structure superplastic forming / diffusion connection method, it belongs to the field of superplastic forming and diffusion connection.This application designs a kind of multi-channel curved surface structure, and in order to solve the problem that multi-channel curved surface structure is deformed excessively and causes channel to close in the process of superplastic forming / diffusion connection, provides a kind of multi-channel curved surface structure superplastic forming / diffusion connection technology using interlayer method diffusion connection, and provides air pressure to channel in the process of superplastic forming.This application is suitable for the heat dissipation type structural member with internal channel and complex geometry, by using interlayer diffusion connection and the superplastic forming technology of pressurizing to the inside of channel auxiliary, complex heat dissipation type structural member with good channel shape, uniform wall thickness and better connection interface mechanical property can be prepared at one time.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of superplastic forming and diffusion bonding, and particularly relates to a method for superplastic forming / diffusion bonding of a multi-channel curved surface structure. BACKGROUND

[0002] Superplastic forming / diffusion bonding (SPF / DB) is an advanced near-net forming process, which combines the advantages of diffusion bonding and superplastic forming, and can realize high-precision forming and large-area seamless bonding of complex metal shapes through plastic deformation and solid-state diffusion reaction. The forming pressure required is small, the residual stress of the prepared component is small, and the SPF / DB process has been widely used in the fields of aerospace, rail transportation, electronics, etc. In particular, for lightweight and high-performance structural components in the field of aerospace, the SPF / DB combined process has unique technical advantages.

[0003] The SPF / DB technology is often used in the field of aerospace to prepare a multi-layer hollow structure. This structure ensures high performance of the component while minimizing the weight of the component to reduce energy consumption. With the in-depth application and research of the SPF / DB technology, the development of the multi-layer hollow structure has evolved from a double-layer structure to a three-layer, four-layer, and sandwich structure. However, the SPF / DB technology has less application in the preparation of structure-function integrated components. With the rapid development of various industries, the demand for such functional structural components is gradually increasing, and the heat dissipation type structure component containing internal channels is the most widely used functional structural component.

[0004] At present, there are many types of heat dissipation structures, which are mainly divided into tube type, fin type, plate type and the like according to the structural form. The tube type heat dissipation component is combined by a plurality of heat dissipation pipes, cooling liquid is passed through the pipes to achieve heat dissipation, the fin type heat dissipation component adds fins on the base material to increase the heat dissipation area to achieve heat dissipation, and the plate type heat dissipation component is composed of parallel metal plates to form narrow channels to increase the heat exchange area to achieve heat dissipation. The most significant heat dissipation effect is the liquid cooling type heat dissipation component, such as the liquid cooling plate. The internal flow channel of the liquid cooling plate is mainly welded by a bottom plate with a water channel groove and a flat cover plate. However, the above heat dissipation components have simple shapes, and the structures thereof generally only have heat dissipation effect, and it is difficult to have other purposes, and the application scenarios are limited. In the multi-flow channel curved surface structure, the flow channel for heat dissipation is in the complex curved surface structure, which can be used for heat dissipation in the field of aerospace, such as being used as a missile shell. The structure not only serves as a shell, but also has heat dissipation effect, so as to reduce the phenomenon that the surface temperature of the shell is too high due to aerodynamic heating, reduce the thermal deformation and thermal stress of the shell structure, improve the safety and reliability of the structure, and if a light material such as aluminum alloy is used to prepare the component, the weight of the aerospace vehicle can be reduced, energy can be saved, and the component has great competitive advantage in the field of aerospace, and the application scenarios are further enriched. In addition, the component manufactured by the SPF / DB technology generally does not rebound, the quality of the formed part is high, the forming stability is good, the design freedom is large, and when the multi-flow channel curved surface heat dissipation structure is prepared, the SPF / DB technology has certain advantages.

[0005] In the preparation of the multi-flow channel curved surface structure, the traditional processing method is difficult to directly form due to the existence of the internal flow channel. When the SPF / DB process is used for forming, the bearing capacity of the flow channel area is weak, and the process specification parameters are too large, which can easily cause the internal flow channel of the component to deform and collapse, reduce the heat dissipation effect of the component, and the process specification parameters are too small, which can easily cause problems such as insufficient diffusion connection and incomplete plate material bonding. In addition, in the superplastic forming process of the multi-flow channel curved surface structure, the deformation degree of the plate material is large, the flow channel can be closed due to the large deformation of the plate material, and the uniformity of the wall thickness is affected. Therefore, solving the problem that the internal flow channel of the multi-flow channel curved surface structure is closed due to excessive deformation in the superplastic forming / diffusion connection process is the key to the superplastic forming / diffusion connection technology of the multi-flow channel curved surface structure. SUMMARY

[0006] In order to solve the above technical problems, the present application provides a method for superplastic forming / diffusion connection of a multi-flow channel curved surface structure.

[0007] The present application designs a multi-flow channel curved surface structure, and in order to solve the problem that the flow channel is closed due to excessive deformation in the superplastic forming / diffusion connection process of the multi-flow channel curved surface structure, a method for superplastic forming / diffusion connection of a multi-flow channel curved surface structure is provided, which adopts an intermediate layer method for diffusion connection, and provides air pressure to the flow channel in the superplastic forming process.

[0008] A method for multi-channel curved surface structure superplastic forming / diffusion bonding, specifically completed by the following steps:

[0009] I. Milling a plate with multiple grooves, making a mask plate according to the shape of the grooves on the plate, cutting the middle layer in the groove area of the plate by using the mask plate, obtaining a milled grooved plate and a cut middle layer;

[0010] II. Taking two milled grooved plates, polishing the surfaces to be flat, removing surface oil stains, and then ultrasonically cleaning the plates with the cut middle layer, and blowing dry with cold air, to obtain a grooved plate to be used and a middle layer to be used;

[0011] III. Placing the middle layer to be used between the two grooved plates to be used, aligning the grooves on the two plates to form a flow channel; connecting a gas pipe to the flow channel opening, and then assembling and welding the two plates, the middle layer and the gas pipe to obtain an assembled plate;

[0012] IV. Spraying an isolation agent on the outer surface of the assembled plate to obtain a sprayed isolation agent assembled plate;

[0013] V. Placing the forming die in the superplastic forming / diffusion bonding equipment and heating the superplastic forming / diffusion bonding equipment to the diffusion bonding process section temperature;

[0014] VI. Placing the sprayed isolation agent assembled plate in the forming die in the superplastic forming / diffusion bonding equipment that has reached the diffusion bonding process section temperature;

[0015] VII. Heating the superplastic forming / diffusion bonding equipment again and vacuumizing through the upper die connected gas pipe, after the forming die reaches the diffusion bonding process section temperature, keeping warm for a period of time, then pressurizing the lower surface of the plate through the lower die exhaust hole to perform diffusion bonding, keeping warm and pressurizing for a period of time after reaching the set air pressure value;

[0016] VIII. After the diffusion bonding is completed, stop the aeration and heating, and stop the vacuumizing;

[0017] IX. After the temperature of the forming die decreases to the superplastic forming process section temperature, keeping warm for a period of time, then aerating the plate through the upper die connected gas pipe and the gas pipe at the flow channel opening to perform superplastic forming, keeping warm and pressurizing for a period of time after reaching the set air pressure value respectively;

[0018] X. After the superplastic forming is completed, stop the aeration and heating, cool down in the furnace, and take out the product, to obtain a multi-channel curved surface structure.

[0019] The beneficial effects of the present application are:

[0020] The present application provides a method for multi-channel curved surface structure superplastic forming / diffusion bonding, which has the following advantages compared with the prior art:

[0021] (1), the first stage of the method provided by the application is a diffusion bonding stage of a multi-flow channel structure, a heterogeneous metal foil (copper foil) with a flow channel region removed is used as an intermediate layer, an element concentration gradient is constructed at the interface, and a transition phase can be formed by reacting with the matrix to promote the diffusion stage, reduce the process parameters, and reduce the degree of flow channel deformation collapse;

[0022] (2), the second stage of the method provided by the application is a superplastic forming stage of a multi-flow channel curved surface structure, internal gas pressure is applied to the flow channel during the superplastic forming of the plate, which can offset the deformation of the flow channel caused by the large deformation of the plate, maintain the basic shape of the flow channel, and thus ensure the heat dissipation effect of the component;

[0023] (3), in the diffusion bonding stage of the multi-flow channel structure, the shape of the intermediate layer used in cooperation with the grooved plate eliminates the influence of the intermediate layer on the flow channel region, reduces the process parameters, improves the quality of the diffusion bonding interface, and improves the mechanical properties of the joint, which is helpful for the subsequent superplastic forming stage and improves the safety of the multi-flow channel curved surface heat dissipation component, thereby improving the overall quality of the forming;

[0024] (4), in the superplastic forming process of the multi-flow channel curved surface structure, internal gas pressure is applied to the flow channel to ensure the basic shape of the flow channel, improve the heat dissipation effect of the component, and avoid the reduction of wall thickness caused by the collapse of the flow channel, which greatly improves the uniformity of the wall thickness of the component and is beneficial to the preparation of high-quality multi-flow channel curved surface heat dissipation structure;

[0025] (5), the application is suitable for heat dissipation type structure with internal flow channel and complex geometry. By using the intermediate layer diffusion bonding and superplastic forming technology with internal pressure applied to the flow channel, a complex heat dissipation type structure with good flow channel shape, uniform wall thickness and good mechanical properties of the joint interface can be prepared at one time. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 It is a schematic diagram of the diffusion bonding stage and the superplastic forming stage of example 1;

[0027] Figure 2 It is a schematic diagram of the upper and lower outer surface of the plate after welding in example 1;

[0028] Figure 3 It is a three-dimensional wireframe diagram of the forming effect of example 1;

[0029] Figure 4 It is a three-dimensional model diagram of the forming effect of example 1;

[0030] Figure 5 It is a three-dimensional model cross-sectional view of the forming effect of example 1;

[0031] Figure 6This is a digital photograph of a multi-channel curved surface structure component including a process section, as shown in Example 1.

[0032] Figure 7 This is a digital photograph of the reverse side of the multi-channel curved surface structure component in Example 1;

[0033] Figure 8 This is a digital photograph of the front (flow channel side) of the multi-channel curved surface structure component in Example 1;

[0034] Figure 9 This is a diagram showing the change in cross-sectional thickness in Example 1;

[0035] Figure 10 This is a comparison diagram of the tensile properties of the molded part and the original base material in Example 1;

[0036] In the diagram, 1-groove plate, 2-intermediate layer, 3-upper mold of forming mold, 4-lower mold of forming mold. Detailed Implementation

[0037] Specific Implementation Method 1: This implementation method provides a superplastic forming / diffusion bonding method for multi-channel curved surface structures, which is specifically completed according to the following steps:

[0038] 1. Mill out a plate with multiple grooves, make a mask template according to the shape of the grooves on the plate, and use the mask template to cut out the middle layer of the groove area on the plate to obtain the milled grooved plate and the cut middle layer.

[0039] 2. Take two milled grooved plates, grind their surfaces smooth, remove surface oil stains, and then ultrasonically clean them together with the cut intermediate layer. Dry them with cold air to obtain the grooved plates and intermediate layer to be used.

[0040] 3. Place the intermediate layer to be used between two grooved plates to be used, align the grooves on the two plates to form a flow channel; connect an air pipe to the flow channel opening, and then weld the two plates, the intermediate layer, and the air pipe together to obtain the welded plate.

[0041] 4. Spray a release agent onto the outer surface of the welded plate to obtain a welded plate coated with the release agent;

[0042] 5. Place the molding die in the superplastic forming / diffusion bonding equipment, and heat the superplastic forming / diffusion bonding equipment to the temperature of the diffusion bonding process section;

[0043] 6. Place the welded plates coated with release agent into the forming mold inside the superplastic forming / diffusion joining equipment at the temperature of the diffusion joining process section;

[0044] Seven, the superplastic forming / diffusion bonding equipment is heated again, vacuum is drawn through the outer connecting air pipe of the upper die, when the forming die reaches the diffusion bonding process section temperature, a period of time is kept, then the lower surface of the plate is pressurized by air through the exhaust hole of the lower die for diffusion bonding, when the air pressure reaches the set value, a period of time is kept for temperature and pressure;

[0045] Eight, after the diffusion bonding is completed, the air supply and heating are stopped, and the vacuum drawing is stopped;

[0046] Nine, when the temperature of the forming die decreases to the superplastic forming process section temperature, a period of time is kept, then the plate is superplastically formed by air through the outer connecting air pipe of the upper die and the air pipe at the flow channel opening, respectively, when the air pressure reaches the set value, a period of time is kept for temperature and pressure;

[0047] Ten, after the superplastic forming is completed, the air supply and heating are stopped, the furnace is cooled, and the temperature is decreased to take out the product, thereby obtaining a multi-flow channel curved surface structure.

[0048] Specific implementation method two: the difference between the embodiment and the specific implementation method one is that the material of the plate in step one is aluminum alloy; the material of the intermediate layer in step one is copper foil; the material of the mask plate in step one is stainless steel; and the opening area of the mask plate in step one is the same as the groove shape on the plate. The other steps are the same as those in the specific implementation method one.

[0049] Specific implementation method three: the difference between the embodiment and the specific implementation method one or two is that the polishing in step two is performed by using 180#-400# SiC sandpaper; and the solvent for the ultrasonic cleaning in step two is anhydrous ethanol, and the time for the ultrasonic cleaning is 2-3 minutes. The other steps are the same as those in the specific implementation method one or two.

[0050] Specific implementation method four: the difference between the embodiment and the specific implementation method one to three is that the material of the air pipe in step three is aluminum alloy; and the outer diameter of the air pipe in step three is 2-3 mm larger than the flow channel size, and the wall thickness is 1 mm. The other steps are the same as those in the specific implementation method one to three.

[0051] Specific implementation method five: the difference between the embodiment and the specific implementation method one to four is that the release agent in step four is boron nitride release agent; and the diffusion bonding process section temperature in step five is 410-540 DEG C. The other steps are the same as those in the specific implementation method one to four.

[0052] Specific implementation method six: the difference between the embodiment and the specific implementation method one to five is that the superplastic forming / diffusion bonding equipment is heated in step seven, and vacuum is drawn through the outer connecting air pipe of the upper die to a vacuum degree of 0.01-0.1 MPa; and the diffusion bonding process section temperature in step seven is 410-540 DEG C. The other steps are the same as those in the specific implementation method one to five.

[0053] Seventh embodiment: the difference between this embodiment and one of the first to sixth embodiments is that the holding time in step seven is 5 min to 10 min; the gas pressure is gradually increased at a rate of 0.1 MPa / min in step seven, and after reaching the set value of 1 MPa to 3 MPa, the pressure is held for 20 min to 40 min. The other steps are the same as the first to sixth embodiments.

[0054] Eighth embodiment: the difference between this embodiment and one of the first to seventh embodiments is that after the temperature of the forming die in step nine is lowered to the superplastic forming process temperature, the temperature is held for 5 min to 10 min; the superplastic forming process temperature in step nine is 370℃ to 460℃. The other steps are the same as the first to seventh embodiments.

[0055] Ninth embodiment: the difference between this embodiment and one of the first to eighth embodiments is that the sheet is superplastically formed by connecting the upper die to the gas pipe in step nine, the gas pressure is gradually increased at a rate of 0.1 MPa / min, and after reaching the set value of 2 MPa to 5 MPa, the pressure is held for 20 min to 40 min to end the superplastic forming stage; the gas pipe at the flow channel opening is used to maintain the shape of the flow channel during the forming process in step nine, the gas pressure is gradually increased at a rate of 0.1 MPa / min, and after reaching the set value of 1 MPa to 3 MPa, the pressure is held until the end of the superplastic forming stage. The other steps are the same as the first to eighth embodiments.

[0056] Tenth embodiment: the difference between this embodiment and one of the first to ninth embodiments is that the upper and lower surfaces of the multi-flow curved surface structure in step ten are curved surfaces with the same width and a depth-to-width ratio of 0.25 to 0.3; the flow channels cross the inside of the multi-flow curved surface structure, the flow channel width is 3 mm to 5 mm, the flow channel height is 1 mm to 1.2 mm, and the flow channel spacing is 4 mm to 8 mm. The other steps are the same as the first to ninth embodiments.

[0057] The following examples are used to verify the beneficial effects of the present application:

[0058] The experimental methods used in the following examples are conventional methods unless otherwise specified. The materials and methods used, unless otherwise specified, are conventional materials and methods in the art, which can be obtained by commercial channels by those skilled in the art.

[0059] Example 1: A method for superplastic forming / diffusion bonding of a multi-flow curved surface structure, which is completed according to the following steps:

[0060] I. Milling a plate with multiple grooves (the width of the grooves is 3 mm, and the depth is 0.5 mm), making a mask plate according to the shape of the grooves on the plate, and cutting the middle layer in the groove area of the plate using the mask plate to obtain a milled grooved plate and a cut middle layer;

[0061] The material of the plate in step one is 5A06 aluminum alloy, and the thickness is 2 mm;

[0062] The material of the middle layer in step one is high-purity copper foil, and the thickness is 10 μm;

[0063] The material of the mask plate in step one is stainless steel, and the thickness is 1 mm;

[0064] The opening area of the mask plate in step one is the same as the shape of the grooves on the plate;

[0065] II. Two milled grooved plates are taken, the surfaces are polished flat, the surface oil is removed, and then the plates and the cut middle layer are ultrasonically cleaned with anhydrous ethanol for 3 min, and then blown dry with cold air to obtain a grooved plate to be used and a middle layer to be used;

[0066] The polishing in step two is performed using 400# SiC sandpaper;

[0067] III. The middle layer to be used is placed between the two grooved plates to be used, the grooves on the two plates are aligned to form a flow channel, a gas pipe (6 mm in outer diameter and 1 mm in wall thickness) is connected to the flow channel, and then the two plates, the middle layer, and the gas pipe are assembled and welded, and the current during assembly and welding is 90 A to obtain an assembled and welded plate;

[0068] The material of the gas pipe in step three is 5A06 aluminum alloy;

[0069] IV. The outer surface of the assembled and welded plate is sprayed with a release agent to obtain a sprayed release agent assembled and welded plate, as shown in Figure 2 ;

[0070] The release agent in step four is boron nitride release agent;

[0071] V. The forming mold is placed in the superplastic forming / diffusion bonding equipment, and the superplastic forming / diffusion bonding equipment is heated to the diffusion bonding process section temperature;

[0072] The diffusion bonding process section temperature in step five is 520°C;

[0073] VI. The sprayed release agent assembled and welded plate is placed in the forming mold in the superplastic forming / diffusion bonding equipment that has reached the diffusion bonding process section temperature, as shown in Figure 1 ;

[0074] Seven, the welding plate material sprayed with the release agent is placed in the superplastic forming / diffusion bonding equipment, the furnace door is opened, the temperature is lowered, the superplastic forming / diffusion bonding equipment is heated again, and vacuum is drawn through the upper die external gas pipe, after the forming die reaches the set temperature (520 DEG C), the lower surface of the plate material is pressurized for diffusion bonding through the lower die exhaust hole, and after the gas pressure set value is reached, the temperature and pressure are kept for 30 min;

[0075] In step seven, the superplastic forming / diffusion bonding equipment is heated and vacuum is drawn through the upper die external gas pipe to a vacuum degree of 0.1 MPa;

[0076] In step seven, the gas pressure is gradually increased at a speed of 0.1 MPa / min, and after reaching the gas pressure set value of 1 MPa, the temperature and pressure are kept for 30 min;

[0077] In step seven, the diffusion bonding process section temperature is 520 DEG C;

[0078] Eight, after the diffusion bonding is completed, stop the ventilation and heating, and stop the vacuum drawing;

[0079] Nine, after the temperature of the forming die decreases to the superplastic forming process section temperature, keep the temperature for a period of time, and then superplastic form the plate material through the upper die external gas pipe and the gas pipe at the flow channel opening, and keep the temperature and pressure for a period of time after reaching the gas pressure set value respectively;

[0080] In step nine, after the temperature of the forming die decreases to the superplastic forming process section temperature, keep the temperature for 5 min;

[0081] In step nine, the superplastic forming process section temperature is 430 DEG C;

[0082] In step nine, during the superplastic forming of the plate material through the upper die external gas pipe and the gas pipe at the flow channel opening, the gas pressure is gradually increased at a speed of 0.1 MPa / min, and after reaching the set value of 3 MPa, the temperature and pressure are kept for 30 min, and the superplastic forming stage is completed;

[0083] In step nine, the gas pipe at the flow channel opening is ventilated to provide the internal gas pressure of the flow channel, so that the flow channel does not deform and collapse during the superplastic forming, the internal gas pressure of the flow channel is set to 1 MPa, the gas pressure is gradually increased at a speed of 0.1 MPa / min, and after reaching the set value of 1 MPa, the temperature and pressure are kept until the superplastic forming stage is completed;

[0084] Ten, after the superplastic forming is completed, stop the ventilation and heating, cool down with the furnace, and take out the piece after cooling, to obtain a multi-flow channel curved surface structure.

[0085] The process schematic diagram of steps six to ten is shown in Figure 1 .

[0086] The effect diagram of the multi-flow channel curved surface heat dissipation component finally formed in the embodiment is shown inFigures 3 to 5 As shown, the upper and lower surfaces are curved, the width a1=a2=a3=a4, the depth-width ratio h / a1 is 0.25, the flow channel traverses the inside of the curved member, the width is 3mm, the height is 1mm, and the flow channel spacing is 4mm. The actual multi-flow curved surface structure member containing the process section is as shown in Figure 6 As shown, the process section is cut off by wire cutting to obtain a multi-flow curved surface heat dissipation structure member as shown in Figure 7 、 8 As shown, in the presence of internal air pressure, the appearance and flow channel shape of the curved member are good.

[0087] The vertical flow channel is cut, the thickness of the characteristic points of the member is measured, and the cross-sectional thickness change curve of Example 1 is as shown in Figure 6 As shown, the member has a small degree of thickness reduction and is safe and reliable.

[0088] As can be seen from Figure 10 Compared with the base material, the tensile strength of the formed member of Example 1 increases, the elongation decreases, the carrying capacity of the formed member under tensile load is improved, and the safety of the member is improved.

[0089] Although the present application has been disclosed with the above preferred embodiments, it is not intended to limit the present application, and any person skilled in the art can make various modifications and modifications without departing from the spirit and scope of the present application, therefore the protection scope of the present application should be defined by the claims.

Claims

1. A method for superplastic forming / diffusion bonding of multi-channel curved surface structures, characterized in that... The method is specifically implemented according to the following steps:

1. Mill out a plate with multiple grooves, make a mask template according to the shape of the grooves on the plate, and use the mask template to cut out the middle layer of the groove area on the plate to obtain the milled grooved plate and the cut middle layer.

2. Take two milled grooved plates, grind their surfaces smooth, remove surface oil stains, and then ultrasonically clean them together with the cut intermediate layer. Dry them with cold air to obtain the grooved plates and intermediate layer to be used.

3. Place the intermediate layer to be used between two grooved plates to be used, align the grooves on the two plates to form a flow channel; connect an air pipe to the flow channel opening, and then weld the two plates, the intermediate layer, and the air pipe together to obtain the welded plate.

4. Spray a release agent onto the outer surface of the welded plate to obtain a welded plate coated with the release agent; 5. Place the molding die in the superplastic forming / diffusion bonding equipment, and heat the superplastic forming / diffusion bonding equipment to the temperature of the diffusion bonding process section; 6. Place the welded plates coated with release agent into the forming mold inside the superplastic forming / diffusion joining equipment at the temperature of the diffusion joining process section; 7. Heat up the superplastic forming / diffusion bonding equipment again and evacuate the vacuum through the external air pipe of the upper mold. After the forming mold reaches the temperature of the diffusion bonding process section, keep it warm for a period of time, and then pressurize the lower surface of the board through the exhaust hole of the lower mold to perform diffusion bonding. After reaching the set air pressure value, keep it warm and pressurized for a period of time.

8. After the diffusion connection is completed, stop the ventilation and heating, and stop the vacuuming.

9. After the temperature of the forming mold drops to the temperature of the superplastic forming process section, keep it at that temperature for a period of time, and then ventilate through the air pipes connected to the upper mold and the air pipes at the flow channel opening to superplastic form the sheet. After reaching the set air pressure value, keep it at that temperature and pressure for a period of time.

10. After superplastic molding and molding, stop the ventilation and heating, cool with the furnace, and remove the part after cooling to obtain a multi-channel curved surface structure part.

2. The method for superplastic forming / diffusion bonding of multi-channel curved surface structures according to claim 1, characterized in that... The material of the plate mentioned in step one is aluminum alloy; the material of the intermediate layer mentioned in step one is copper foil; the material of the mask template mentioned in step one is stainless steel; the opening area of ​​the mask template mentioned in step one has the same shape as the groove on the plate.

3. The method for superplastic forming / diffusion bonding of multi-channel curved surface structures according to claim 1, characterized in that... The polishing described in step two is performed using 180# to 400# SiC sandpaper; the ultrasonic cleaning solvent described in step two is anhydrous ethanol, and the ultrasonic cleaning time is 2 to 3 minutes.

4. The method for superplastic forming / diffusion bonding of multi-channel curved surface structures according to claim 1, characterized in that... The trachea mentioned in step three is made of aluminum alloy; the outer diameter of the trachea mentioned in step three is 2-3 mm larger than the flow channel size, and the wall thickness is 1 mm.

5. The method for superplastic forming / diffusion bonding of multi-channel curved surface structures according to claim 1, characterized in that... The isolating agent mentioned in step four is boron nitride isolating agent; the temperature of the diffusion bonding process section mentioned in step five is 410℃~540℃.

6. The method for superplastic forming / diffusion bonding of multi-channel curved surface structures according to claim 1, characterized in that... In step seven, the superplastic forming / diffusion bonding equipment is heated and a vacuum is drawn through the external gas pipe of the upper mold to a vacuum degree of 0.01MPa to 0.1MPa; the temperature of the diffusion bonding process section in step seven is 410℃ to 540℃.

7. The method for superplastic forming / diffusion bonding of multi-channel curved surface structures according to claim 1, characterized in that... The heat preservation time mentioned in step seven is 5 min to 10 min; in step seven, the air pressure is gradually increased at a rate of 0.1 MPa / min, and after reaching the air pressure set value of 1 MPa to 3 MPa, the heat preservation and pressure preservation are maintained for 20 min to 40 min.

8. The method for superplastic forming / diffusion bonding of multi-channel curved surface structures according to claim 1, characterized in that... In step nine, after the temperature of the mold to be formed drops to the temperature of the superplastic forming process section, it is kept at that temperature for 5 to 10 minutes; the temperature of the superplastic forming process section mentioned in step nine is 370℃ to 460℃.

9. The method for superplastic forming / diffusion bonding of multi-channel curved surface structures according to claim 1, characterized in that... In step nine, the sheet material is superplastically formed through an external air pipe connected to the upper mold. The air pressure is gradually increased at a rate of 0.1 MPa / min until it reaches the set value of 2 MPa to 5 MPa. After reaching this value, the material is held at the temperature and pressure for 20 to 40 minutes, and the superplastic forming stage ends. In step nine, air is introduced through an air pipe at the runner opening to maintain the runner shape during the forming process. The air pressure is gradually increased at a rate of 0.1 MPa / min until it reaches the set value of 1 MPa to 3 MPa. After reaching this value, the material is held at the temperature and pressure until the superplastic forming stage ends.

10. The method for superplastic forming / diffusion bonding of multi-channel curved surface structures according to claim 1, characterized in that... The upper and lower surfaces of the multi-channel curved surface structure mentioned in step ten are curved, with the same width and a depth-to-width ratio of 0.25 to 0.

3. The flow channels run through the interior of the multi-channel curved surface structure, with a flow channel width of 3 mm to 5 mm, a flow channel height of 1 mm to 1.2 mm, and a flow channel spacing of 4 mm to 8 mm.

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