A manufacturing method of a lightweight high-bearing-capacity skin friction stir welding superplastic forming

Abstract

The present application relates to a kind of lightweight high bearing skin friction stir welding superplastic forming manufacturing method, belong to metal processing forming field;Skin structure design is simulated, its rationality is verified and further optimized design.Processing skin layer and reinforcing rib layer after using friction stir welding this kind of weld high strength, small heat output connection form, skin layer and reinforcing rib layer are connected together;The whole skin structure connected using certain design surface hot forming model is completed the superplastic forming of reinforcing rib layer using superplastic forming processing mode.The method of the present application can reduce the overall skin structure 40% weight under the condition of same material, same bearing capacity, realize the lightweight manufacturing of high bearing skin component in true sense.

Description

Technical Field

[0001] This invention belongs to the field of metal processing and forming, and relates to a manufacturing method for lightweight, high load-bearing skin friction stir bonding superplastic forming. Background Technology

[0002] Metal skin materials are widely used in aircraft, automobiles, and other fields. Due to the large span of the skin material, the maximum load the structure itself can withstand is limited. To improve the load-bearing capacity of the skin material, a common method is to add reinforcing ribs. This method can improve its strength and stiffness without increasing the thickness of the skin workpiece itself. However, this type of skin material with reinforcing ribs is heavy and has a relatively low load-bearing capacity. The existing process for manufacturing reinforcing skin involves: flatbed machining + reinforcing rib bending + pressure spot welding. However, traditional welding processes involve high heat input, easily causing workpiece deformation after welding, resulting in varying degrees of skin distortion, requiring extensive manual straightening, and making the process complex. Existing processes suffer from problems such as complex forming of reinforcing skin workpieces, insufficient weld connection strength, easy deformation, low material utilization, long production cycles, and complex manual operations. Summary of the Invention

[0003] The technical problem solved by this invention is to overcome the shortcomings of the prior art and propose a manufacturing method for lightweight, high-load-bearing skin friction stir bonding superplastic forming, which can reduce the weight of the overall skin structure by 40% under the same material and load-bearing capacity, and truly realize the lightweight manufacturing of high-load-bearing skin components.

[0004] The solution of the present invention is: A manufacturing method for lightweight, high-load-bearing skin friction stir bonding superplastic forming includes: Step 1: Design the skin structure process according to the design requirements, and form a preliminary process model diagram of the skin; Step 2: Using the preliminary process model diagram as input, perform finite element simulation to verify the load-bearing capacity of the skin. If the simulation results do not meet the load-bearing and weight design requirements, return to Step 1 and iteratively optimize the structural process design of the skin. Continue until the simulation results meet the load-bearing and weight design requirements, and obtain the final compliant skin process model diagram, then proceed to Step 3. The compliant skin process model includes the skin layer, the hollow reinforcing rib layer, and the weight-reducing groove. Step 3: Design the skin layer structure and reinforcing rib layer according to the hollow reinforcing rib layer in the skin process model drawing; cut the skin layer structure and reinforcing rib layer into materials; Step 4: Mill the skin layer structure after cutting to mill out the shape and size required for subsequent welding with the reinforcing rib layer, as well as the weight reduction groove, to obtain the skin layer structure. Step 5: Remove impurities and oil from the skin layer and reinforcing rib layer; weld the skin layer and reinforcing rib layer using friction stir welding. Step 6: Fit the welded skin layer structure and reinforcing rib layer with the corresponding forming mold; ventilate the skin layer structure and reinforcing rib layer evenly, so that the reinforcing rib layer is superplastically formed and fits into the mold cavity to obtain a hollow reinforcing rib layer; Step 7: Post-process the formed hollow reinforcing rib skin to remove the mold positioning and stirring head feed allowance; and eliminate residual stress through process treatment to reduce shape error and improve the overall load strength and dimensional stability of the skin.

[0005] In the above-mentioned manufacturing method for lightweight, high-load-bearing skin superplastic forming using friction stir bonding, the specific details of the skin structure process design in step one are as follows: Determine the structural form and material selection for the skin and reinforcing ribs.

[0006] In the above-mentioned manufacturing method of lightweight high load-bearing skin friction stir connection superplastic forming, in step two, the finite element simulation is used to verify whether the skin meets the load-bearing requirements and weight design requirements.

[0007] In the above-mentioned manufacturing method for lightweight, high-load-bearing skin superplastic forming using friction stir bonding, step three involves the following method for fabricating the reinforcing rib layer: Based on the skin layer, the mold positioning and the feed allowance of the stirring head are designed and added to form the skin layer structure; after filling the weight reduction groove on the skin layer structure, the skin layer plate is obtained; the skin layer plate and the reinforcing rib layer are cut according to the design drawings.

[0008] In the above-mentioned manufacturing method of lightweight high load-bearing skin friction stir connection superplastic forming, in step four, after obtaining the skin layer structure, the skin layer structure and the reinforcing rib layer after blanking are deburred.

[0009] In the above-mentioned manufacturing method of lightweight high load-bearing skin friction stir connection superplastic forming, in step five, a chemical surface treatment method is used to clean the skin layer structure and the reinforcing rib layer to ensure that the skin layer structure and the reinforcing rib layer meet the pre-welding requirements.

[0010] In the above-mentioned manufacturing method of lightweight high load-bearing skin friction stir connection superplastic forming, in step five, when welding the skin layer structure and the reinforcing rib layer, the weld position is welded along the outer edge shape of the reinforcing rib, and a hollow position in the middle is reserved for superplastic forming of the middle reinforcing rib layer.

[0011] In the above-mentioned manufacturing method of lightweight high load-bearing skin friction stir joint superplastic forming, the welding parameters are as follows: welding tilt angle is set to 1°, shoulder pressing is 0.05-0.30 mm, welding speed is 150-500 mm / min, and rotation speed is 700-1200 rpm.

[0012] In the aforementioned manufacturing method for lightweight, high-load-bearing skin superplastic forming using friction stir bonding, step six specifically involves obtaining the hollow reinforcing rib layer as follows: S61. Based on the designed hollow reinforcing rib layer structure, design a superplastic forming mold with a corresponding cavity. S62. Secure the mold to the pressure platform and connect the air supply line; S63. Mold closing: Heat the mold and skin to a certain temperature, and uniformly pass a certain amount of inert gas through the skin layer structure and the reinforcing rib layer. The reinforcing rib layer is then superplastically molded to fit into the mold cavity to obtain a hollow reinforcing rib layer. A pressure platform is used to apply the mold closing force. S64. Continue to supply argon gas at a higher pressure between the skin layer structure and the reinforcing rib layer through the vent pipe; maintain the pressure for a certain period of time to ensure that the hollow reinforcing rib layer is completely bonded to the lower mold cavity of the mold. S65. After the mold temperature has cooled down, remove the skin.

[0013] In the above-mentioned manufacturing method of lightweight high load-bearing skin friction stir connection superplastic forming, step seven adopts solution aging, stress relief annealing, and processing and polishing processes to eliminate residual stress, reduce shape error, and improve the overall load strength and dimensional stability of the skin.

[0014] The advantages of this invention compared to the prior art are: (1) The hollow reinforcing rib skin structure design of the present invention can effectively reduce the weight of the workpiece and achieve lightweighting of the reinforcing rib skin component. Under the same material and the same load-bearing capacity, the weight of the reinforcing rib structure can be reduced by 40%, truly achieving lightweighting of the skin component; (2) This invention, through solid-state welding methods such as friction stir welding, can further improve the weld strength between the reinforcing ribs and the skin, reduce heat input and skin deformation, thereby improving the load strength of the hollow reinforcing rib and skin workpiece. Compared with diffusion bonding, friction stir welding has stronger quality controllability and monitorability. Applying it to the local connection of aluminum alloy thin-walled structures and controlling the welding form according to requirements enables the precise forming of aluminum alloy hollow thin-walled structures, reduces machining workload, and improves efficiency. (3) The superplastic forming process after welding in this invention reduces the difficulty of traditional ribbed skin processes, enables integrated forming of skins of different shapes, has high surface accuracy, improves production efficiency, shortens cycle time, improves workpiece qualification rate and quality, and reduces costs. Welding is performed first in a flat state, and then the surface and reinforcing ribs are formed. The welding difficulty is low, deformation control is easy, and forming accuracy is high. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the forming method of the present invention; Figure 2 This is a process model diagram of the flat panel skin part of the present invention; Figure 3 This is a cross-sectional model diagram of the flat panel skin part of the present invention; Figure 4 This is a schematic diagram of the manufacturing process of the flat skin structure product of the present invention; Figure 5 This is a schematic diagram of the skin layer structure of the flat skin structure product of the present invention; Figure 6 This is a schematic diagram of the reinforcing rib layer structure of the flat skin structure product of the present invention; Figure 7 This is a schematic diagram of the skin layer structure after milling of the flat skin structure product of the present invention. Detailed Implementation

[0016] The present invention will be further described below with reference to the embodiments.

[0017] This invention provides a manufacturing method for lightweight, high-load-bearing skin friction stir bonding superplastic forming, which can reduce the overall weight of the skin structure by 40% under the same material and load-bearing capacity, truly realizing the lightweight manufacturing of high-load-bearing skin components.

[0018] Manufacturing methods for lightweight, high-load-bearing skin friction stir bonding superplastic forming, such as... Figure 1 As shown, the specific steps include the following: Step 1: Design the skin structure process according to the design requirements, and create a preliminary process model diagram of the skin. The specific contents of the skin structure process design are: determining the structural form and material selection of the skin and reinforcing ribs.

[0019] Step 2: Using the preliminary process model diagram as input, perform finite element simulation to verify the load-bearing capacity of the skin. If the simulation results do not meet the load-bearing and weight design requirements, return to Step 1 and perform iterative optimization of the structural process design of the skin. Continue until the simulation results meet the load-bearing and weight design requirements, and obtain the final skin process model diagram that meets the requirements, then proceed to Step 3. The skin process model that meets the requirements includes skin layer 1, hollow reinforcing rib layer 2, and weight reduction groove 3.

[0020] In this invention, finite element simulation is used to verify whether the skin meets the load-bearing requirements and weight design requirements.

[0021] Step 3: Design the skin layer 8 and the reinforcing rib layer 4 according to the hollow reinforcing rib layer 2 in the skin process model diagram; cut the skin layer 8 and the reinforcing rib layer 4 into materials.

[0022] The method for fabricating reinforcing rib layer 4 is as follows: Based on the skin layer 1, design and add mold positioning 5 and stirring head feed allowance 6 to form skin layer structure 7; fill the weight reduction groove 3 on the skin layer structure 7 to obtain skin layer plate 8; cut the skin layer plate 8 and reinforcing rib layer 4 according to the design drawing.

[0023] Step 4: Mill the cut skin layer structure 8 to mill out the shape and size required for subsequent welding with the reinforcing rib layer 4, as well as the weight reduction groove 3, to obtain the skin layer structure 7.

[0024] After obtaining the skin layer structure 7, the skin layer structure 7 and the reinforcing rib layer 4 after blanking are deburred.

[0025] Step 5: Remove impurities and oil stains from the skin layer structure 7 and the reinforcing rib layer 4; weld the skin layer structure 7 and the reinforcing rib layer 4 by friction stir welding.

[0026] The skin layer structure 7 and the reinforcing rib layer 4 are cleaned using a chemical surface treatment method to ensure that the skin layer structure 7 and the reinforcing rib layer 4 meet the pre-welding requirements.

[0027] When welding the skin layer structure 7 and the reinforcing rib layer 4, the weld seam is welded along the outer edge of the reinforcing rib, leaving a hollow space in the middle for superplastic forming of the hollow reinforcing rib layer 2. The welding parameters are: welding angle set to 1°, shoulder pressing down 0.05-0.30mm, welding speed 150-500 mm / min, and rotation speed 700-1200 rpm.

[0028] Step 6: Fit the welded skin layer structure 7 and reinforcing rib layer 4 with the corresponding forming mold; ventilate the skin layer structure 7 and reinforcing rib layer 4 evenly, so that the reinforcing rib layer 4 is superplastically molded to fit the mold cavity to obtain the hollow reinforcing rib layer 2.

[0029] The specific method for obtaining the hollow reinforcing rib layer 2 is as follows: S61. Based on the designed hollow reinforcing rib layer 2 structure, design a superplastic forming mold with a corresponding cavity. S62. Secure the mold to the pressure platform and connect the air supply line; S63. Mold closing: Heat the mold and skin to a certain temperature, and uniformly pass a certain amount of inert gas through the skin layer structure 7 and the reinforcing rib layer 4, so that the reinforcing rib layer 4 is superplastically formed to fit into the mold cavity to obtain the hollow reinforcing rib layer 2, and apply the mold closing force using a pressure platform. S64. Continue to supply argon gas at a higher pressure between the skin layer structure 7 and the reinforcing rib layer 4 through the vent pipe; maintain the pressure for a certain period of time to ensure that the hollow reinforcing rib layer 2 is completely fitted and formed with the lower mold cavity; S65. After the mold temperature has cooled down, remove the skin.

[0030] Step 7: Post-process the formed hollow reinforcing rib skin, remove mold positioning 5 and stirring head infeed 6; and eliminate residual stress through process treatment to reduce shape error and improve the overall load strength and dimensional stability of the skin.

[0031] By employing solution aging, stress-relief annealing, and machining and polishing processes, residual stress is eliminated, shape errors are reduced, and the overall load-bearing strength and dimensional stability of the skin are improved.

[0032] Example This example provides a lightweight, high-load-bearing flat-plate hollow ribbed skin composite manufacturing method using friction stir welding / superplastic forming. The specific steps of this method are as follows: Specifically, in step 1, based on design requirements and technical conditions, the structural process design of the skin is first carried out to determine the structural form and material selection of the skin and reinforcing ribs; In the structural and process design of the target-shaped flat skin, the skin reinforcing ribs are designed as a cross-shaped hollow "U" structure. The flat skin product consists of a skin layer and a reinforcing rib layer. For product lightweighting, the skin layer is made of 5A06 aluminum alloy with a thickness of 3mm, and weight-reducing grooves are designed in some locations. To improve the overall load-bearing capacity of the skin, the reinforcing rib layer is made of 1mm thick 7075 aluminum alloy, whose yield strength at room temperature is typically between 520-550MPa, and its tensile strength can reach 560-600MPa.

[0033] Specifically, in step 2, the load-bearing capacity of the designed flat ribbed skin workpiece is verified by finite element simulation, and the skin structure is continuously optimized, such as fillet features, rib aspect ratio, and connection form. After multiple rounds of simulation verification and iterative optimization, it is confirmed that the final flat ribbed skin product meets the requirements of the technical specifications for weight, load-bearing capacity, and structural form. The overall flat skin product includes skin layer 1, hollow reinforcing rib layer 2, and skin layer weight-reducing groove 3. The final flat ribbed skin product sample is shown below. Figure 2 As shown in the diagram, the reinforcing rib structure is as follows: Figure 3 As shown.

[0034] Specifically, in step 3, after completing the process design and verification stage, based on the skin structure design drawing and process model drawing, and fully considering the friction stir welding and superplastic forming processes, the process part design is completed, and the skin layer structure and reinforcing rib layer are cut and processed according to the process part design drawing. The main steps are as follows: Based on the skin structure design drawing, and considering the machining allowance and forming positioning during the specific stirring friction and superplastic forming process, the specific skin process part drawing is designed.

[0035] For example, the process drawing of the designed flat panel skin product is as follows: Figure 4 As shown, 5 is the positioning slot for the skin to cooperate with the mold during the superplastic forming process, which is intended to prevent the part from deviating from the predetermined cavity position during the superplastic forming process. 6 is the starting welding position of the stirring head reserved to prevent damage to the product itself during the friction stir welding process.

[0036] The sheet metal is cut using laser cutting. The reinforcing ribs are laser-cut into a cross-shaped structure. After cutting, burrs on the surface of the reinforcing rib material are removed by grinding. Based on the above-mentioned structural process design drawing of the skin, the cutting diagrams for the skin layer and reinforcing layer are as follows: Figure 5 , Figure 6 As shown.

[0037] The skin layer is machined with the required shape and size for welding to the reinforcing rib layer, along with weight-reducing grooves, according to the designed locations. Figure 7 As shown, the shape and size to be milled are the same as those of the reinforcing rib layer. After machining, the edges are sanded until there are no obvious burrs.

[0038] After machining, the skin layer and the cross-shaped reinforcing rib layer are soaked in a chemical cleaning agent at 80°C for 120 minutes to remove oxides, oil, cutting fluid, etc. from the material surface, and then taken out and dried.

[0039] Specifically, in step 5, friction stir welding is used to fix and connect the skin layer and the reinforcing rib layer. When connecting the skin layer and the reinforcing rib layer using friction stir welding, the welding stirring head enters from the pre-reserved position on the skin layer and connects the skin layer and the reinforcing rib layer along the edge of the reinforcing rib. The weld should follow the shape of the reinforcing rib, leaving a hollow space in the middle for superplastic forming of the reinforcing rib structure. The welding parameters are as follows: Specifically, in step 6, after welding, superplastic forming is performed to obtain a skin workpiece with hollow reinforcing ribs. This example designs and manufactures the mold required for superplastic forming of the flat skin reinforcing ribs. The forming mold includes an upper mold with a welding angle of 1°, a shoulder pressing down of 0.15 mm, a welding speed of 300 mm / min, and a rotation speed of 950 rpm; a lower mold; lifting lugs; baffles; temperature measuring holes; venting holes; through-pipe grooves; positioning pins; and a clamping platform. The upper and lower molds cooperate to form the mold cavity of the flat skin. The mold includes a venting pipe, and the mold cavity and the venting pipe are connected. The skin is placed between the upper and lower molds, and the pressure required for thermoforming is applied through the upper and lower molds to initially fit the skin's edges against the mold surface. The mold is heated to a predetermined temperature and held for a period of time. Then, high-pressure gas is introduced between the skin layer and the reinforcing rib layer through the ventilation pipe, and a clamping force is applied by a pressure platform. After sufficient pressure holding, the corresponding parts of the skin and reinforcing rib layers completely adhere to the lower surface of the mold, resulting in a hollow reinforcing rib structure identical to the mold surface. After full forming, the pressure and argon gas flow rate are reduced, and the skin is removed.

[0040] Specifically, in step 7, the ventilation holes of the thermoformed workpiece are sealed by welding, and the locating holes and welding stirring head allowance are removed to improve the load-bearing strength of the ribs and skin, reduce surface accuracy errors, and finally obtain a lightweight, high-load-bearing flat hollow ribbed skin with acceptable dimensions and performance. This invention is suitable not only for relatively simple skin structures such as flat ribbed skins, but also for the processing and manufacturing of curved skins.

[0041] The hollow reinforcing rib skin structure design of this invention can effectively reduce the weight of the workpiece, achieving lightweighting of the reinforcing rib skin component. Under the same material and load-bearing capacity, the weight of the reinforcing rib structure can be reduced by 40%, truly achieving lightweighting of the skin component; This invention utilizes a solid-state welding method, friction stir welding, to further improve the weld strength between the reinforcing ribs and the skin, reduce heat input and skin deformation, thereby increasing the load-bearing capacity of the hollow reinforcing rib and skin workpiece. Compared to diffusion bonding, friction stir welding offers greater quality control and monitorability. Applying it to the local connections of thin-walled aluminum alloy structures and controlling the welding method according to requirements enables precise forming of hollow thin-walled aluminum alloy structures, reducing machining work and improving efficiency. The superplastic forming process after welding in this invention reduces the difficulty of traditional ribbed skin processes, enabling integrated forming of skins of different shapes with high surface accuracy. This improves production efficiency, shortens cycle time, increases workpiece pass rate and quality, and reduces costs. Welding is performed first in a flat state, followed by forming the surface and reinforcing ribs. This reduces welding difficulty, facilitates deformation control, and achieves high forming accuracy.

[0042] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

Claims

1. A manufacturing method for a lightweight, high-load-bearing skin friction stir bonding superplastic forming process, characterized in that: include: Step 1: Design the skin structure process according to the design requirements, and form a preliminary process model diagram of the skin; Step 2: Using the preliminary process model diagram as input, perform finite element simulation to verify the skin's load-bearing capacity; When the simulation results do not meet the load-bearing requirements and weight design requirements, return to step one and iteratively optimize the structural process design of the skin; until the simulation results meet the load-bearing requirements and weight design requirements, obtain the final skin process model diagram that meets the requirements, and proceed to step three; the skin process model that meets the requirements includes the skin layer (1), the hollow reinforcing rib layer (2), and the weight reduction groove (3). Step 3: Design the skin layer (8) and the reinforcing rib layer (4) according to the hollow reinforcing rib layer (2) in the skin process model diagram; cut the skin layer (8) and the reinforcing rib layer (4) into pieces; Step 4: Mill the cut skin layer plate (8) to mill out the shape and size required for subsequent welding with the reinforcing rib layer (4) and the weight reduction groove (3) to obtain the skin layer structure (7). Step 5: Remove impurities and oil stains from the skin layer structure (7) and the reinforcing rib layer (4); weld the skin layer structure (7) and the reinforcing rib layer (4) by friction stir welding; Step 6: Fit the welded skin layer structure (7) and reinforcing rib layer (4) with the corresponding forming mold; ventilate the skin layer structure (7) and reinforcing rib layer (4) evenly, so that the reinforcing rib layer (4) is formed by superplastic forming and fitting the mold cavity to obtain the hollow reinforcing rib layer (2). The specific method for obtaining the hollow reinforcing rib layer (2) is as follows: S61. Based on the designed hollow reinforcing rib layer (2) structure, design the corresponding cavity superplastic forming mold; S62. Secure the mold to the pressure platform and connect the air supply line; S63. Mold closing: Heat the mold and skin to a certain temperature, and uniformly pass a certain amount of inert gas through the skin layer structure (7) and the reinforcing rib layer (4) so ​​that the reinforcing rib layer (4) is formed by superplastic forming and fits into the mold cavity to obtain the hollow reinforcing rib layer (2), and apply the mold closing force using a pressure platform. S64. Continue to supply argon gas at a higher pressure between the skin layer structure (7) and the reinforcing rib layer (4) through the vent pipe; maintain the pressure for a certain period of time to ensure that the hollow reinforcing rib layer (2) is completely fitted and formed with the lower mold cavity; S65. After the mold temperature has cooled down, remove the skin. Step 7: Post-process the formed hollow reinforcing rib skin, remove the mold positioning (5) and the cutting allowance of the stirring head (6); and eliminate residual stress through process treatment to reduce shape error and improve the overall load strength and dimensional stability of the skin. By employing solution aging, stress-relief annealing, and machining and polishing processes, residual stress is eliminated, shape errors are reduced, and the overall load-bearing strength and dimensional stability of the skin are improved.

2. The manufacturing method of a lightweight, high-load-bearing skin friction stir bonding superplastic forming according to claim 1, characterized in that: In step one, the specific details of the skin structure process design are as follows: Determine the structural form and material selection for the skin and reinforcing ribs.

3. The manufacturing method of a lightweight, high-load-bearing skin friction stir superplastic forming according to claim 1, characterized in that: In step two, finite element simulation is used to verify whether the skin meets the load-bearing requirements and weight design requirements.

4. The manufacturing method of a lightweight, high-load-bearing skin friction stir superplastic forming according to claim 1, characterized in that: In step three, the method for fabricating the reinforcing rib layer (4) is as follows: Based on the skin layer (1), the mold positioning (5) and the stirring head cutting allowance (6) are designed and added to form the skin layer structure (7); after filling the weight reduction groove (3) on the skin layer structure (7), the skin layer plate (8) is obtained; the skin layer plate (8) and the reinforcing rib layer (4) are cut according to the design drawing.

5. The manufacturing method of a lightweight, high-load-bearing skin friction stir superplastic forming according to claim 1, characterized in that: In step four, after obtaining the skin layer structure (7), the skin layer structure (7) and the reinforcing rib layer (4) after cutting are deburred.

6. The manufacturing method of a lightweight, high-load-bearing skin friction stir bonding superplastic forming according to claim 1, characterized in that: In step five, a chemical surface treatment method is used to clean the skin layer structure (7) and the reinforcing rib layer (4) to ensure that the skin layer structure (7) and the reinforcing rib layer (4) meet the pre-welding requirements.

7. The manufacturing method of a lightweight, high-load-bearing skin friction stir superplastic forming according to claim 6, characterized in that: In step five, when welding the skin layer structure (7) and the reinforcing rib layer (4), the weld seam is welded along the outer edge of the reinforcing rib, and a hollow position is reserved in the middle to form the hollow reinforcing rib layer (2) by superplastic forming.

8. The manufacturing method of a lightweight, high-load-bearing skin friction stir superplastic forming according to claim 7, characterized in that: The welding parameters are as follows: welding angle is set to 1°, shoulder pressure is 0.05-0.30 mm, welding speed is 150-500 mm / min, and rotation speed is 700-1200 rpm.

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