A method of forming a titanium / aluminum laminated composite shell

Abstract

The application provides a forming method of a titanium / aluminum layered composite shell, and belongs to the technical field of non-ferrous metal preparation. In view of the characteristics of high strength corrosion resistance of titanium alloy, light weight of aluminum alloy and low price, a threaded groove structure is processed on the inner surface of the outer titanium alloy, and a high-energy ultrasonic energy field is applied in the process of internal spinning forming, so as to promote plastic deformation and reduce the internal residual stress of the titanium / aluminum composite shell. The layered composite shell component of the titanium outer layer and the aluminum inner layer with low stress and three-dimensional interface connection of mechanical interlocking is formed, and has the advantages of saving raw materials, low cost, good forming performance, three-dimensional mechanical interlocking of the titanium / aluminum interface and the like. The method is advanced in process, and is an ideal method for preparing a high-performance layered composite pipe.

Description

Technical Field

[0001] This invention belongs to the technical field of non-ferrous metal preparation, and specifically discloses a method for forming a titanium / aluminum layered composite shell. Background Technology

[0002] Aluminum alloys possess advantages such as low density, high strength, low price, and certain corrosion resistance, making them widely used in aerospace, underwater equipment, and vehicle manufacturing. Compared to aluminum alloys, titanium alloys offer superior strength and corrosion resistance, but they are more expensive and have a higher density. Combining the advantages of both titanium and aluminum alloys, the fabrication of titanium-aluminum composite components holds great promise for a wide range of applications.

[0003] Titanium / aluminum layered composite shells combine the performance advantages of both titanium and aluminum alloys, offering lightweight, high strength, and flexible structural design. They can be fabricated with titanium alloy layers on the outside or inside, depending on the application environment. The fabrication methods for layered composite shells / plates mainly include solid-solid composite rolling technology, diffusion bonding technology, solid-liquid semi-solid rolling technology, and liquid-liquid bimetallic composite casting technology. For fabricating thin-walled shell components, spin forming technology has unique advantages.

[0004] In the process of preparing titanium-aluminum layered composite shells using spinning technology, the strength of titanium alloy is higher than that of aluminum alloy. When a load is applied under certain heating temperature conditions, aluminum alloy and titanium alloy undergo plastic deformation first. At the same time, under medium and low temperature conditions, titanium alloy is difficult to undergo plastic deformation, resulting in uncoordinated plastic deformation between the two and low interfacial bonding strength, which limits the application of titanium-aluminum layered composite shells. Summary of the Invention

[0005] This invention provides a forming method for a titanium / aluminum layered composite shell, which overcomes the technical problem in the prior art where the plastic deformation of the titanium / aluminum layered composite shell is not coordinated during heat forming, resulting in a reduction in the interfacial bonding strength.

[0006] The forming method of the above-mentioned titanium / aluminum layered composite shell includes the following steps:

[0007] S1, machining titanium alloy outer cylinder and aluminum alloy inner cylinder

[0008] The titanium alloy outer cylinder and the aluminum alloy inner cylinder are machined to the preset dimensions. Threaded grooves are machined on the inner surface of the titanium alloy outer cylinder, and a step is machined at the first end of the aluminum alloy inner cylinder.

[0009] S2, assemble the aluminum alloy inner cylinder into the titanium alloy outer cylinder, and press the first end of the aluminum alloy inner cylinder against the first end of the titanium alloy outer cylinder to form a titanium / aluminum assembly.

[0010] S3, High-energy ultrasonic-assisted spinning forming of titanium / aluminum composite shell

[0011] The titanium / aluminum assembly prepared in step S2 is mounted on an internal spinning press and spun into shape while being subjected to ultrasonic vibration. After spinning is completed, ultrasonic vibration is continued to be applied to regulate the internal residual stress of the titanium / aluminum composite shell.

[0012] S4. Place the spun titanium / aluminum composite shell on a lathe, clamp it with the lathe chuck, and machine the outer surface of the titanium / aluminum composite shell. After machining, remove the titanium / aluminum composite shell.

[0013] S5, storage

[0014] Storage temperature: 20℃, relative humidity: ≤10%.

[0015] The internal spinning press used in step S3 includes an internal spinning press frame, an internal spinning press spindle box, an internal spinning press spindle, an internal spinning press chuck, a support frame, an ultrasonic component, an ultrasonic power supply, a sliding frame, a spinning shaft, a spinning head, and a hydraulic cylinder. The internal spinning press spindle box, support frame, and sliding frame are sequentially arranged on the internal spinning press frame. The internal spinning press spindle is driven to rotate by the internal spinning press spindle box, and an internal spinning press chuck is installed on the output end. The support frame is coaxially arranged with the internal spinning press chuck. The ultrasonic component is arranged along the axial direction of the support frame at a preset interval. Each ultrasonic component group includes multiple ultrasonic pressure heads arranged circumferentially along the support frame; an ultrasonic power supply provides power to the ultrasonic pressure heads; a spinning shaft is mounted on a sliding frame and coaxially arranged with the inner spinning machine chuck, and is driven by a hydraulic cylinder to move axially; the spinning head includes a spinning head inner ring and cylindrical rolling elements; the spinning head inner ring has a frustum-shaped structure, with its central hole rotatably connected to the spinning shaft, its small end face facing the support frame, and its large end face facing the sliding frame; the cylindrical rolling elements surround the outer side of the spinning head inner ring, with their central axis parallel to the outer wall of the spinning head inner ring;

[0016] Step S3 includes:

[0017] t1, Install the titanium / aluminum assembly in the support frame, and clamp the second end onto the chuck of the internal spinning press, so that the center line of the titanium / aluminum assembly coincides with the center line of the main shaft of the internal spinning press. After adjustment, position and clamp the titanium / aluminum assembly.

[0018] t2, open the spindle box, ultrasonic press head, and hydraulic cylinder of the internal spinning press to make the titanium / aluminum assembly rotate, the spinning shaft is fed axially, and the cylindrical rolling body spins the titanium / aluminum assembly while performing ultrasonic vibration.

[0019] In the aforementioned internal spinning press, the spinning shaft is provided with a threaded section; the spinning head also includes a retainer, which passes through the cylindrical rolling element and has its two ends connected to the outer wall of the inner ring of the spinning head and the spinning shaft, respectively; a washer and a lock nut are fitted on the threaded section of the spinning shaft to press the retainer.

[0020] The aforementioned internal spinning press also includes an internal spinning press guide rail; the internal spinning press guide rail is mounted on the internal spinning press frame; and the sliding frame is mounted on the internal spinning press guide rail.

[0021] The aforementioned internal spinning press is controlled by an electrical control cabinet.

[0022] In step S1, the machining steps of the titanium alloy outer cylinder are as follows: the titanium alloy outer cylinder is clamped on the lathe by the lathe chuck, and the inner surface is machined by turning. The inner diameter is 100mm, the upper deviation is 0.1mm, and the lower deviation is 0.

[0023] An internal thread groove is machined on the inner surface of the titanium alloy outer cylinder. The depth of the thread groove is 0.1-0.5 mm and the pitch is 4 mm.

[0024] The machining steps of the aluminum alloy inner cylinder are as follows: the aluminum alloy inner cylinder is clamped on the lathe by the lathe chuck, the outer surface is machined, the outer diameter is 100mm, the upper deviation is 0.05mm, the lower deviation is 0.15mm, and a step is machined at the first end, with an outer diameter of 104mm and a thickness of 3mm.

[0025] The inner surface of the aluminum alloy inner cylinder is machined to an inner diameter of 94mm, with an upper deviation of 0.1mm and a lower deviation of 0.

[0026] In step S3, multi-pass forming is adopted, and the single-pass spinning deformation is less than 15%. The total spinning deformation reaches the preset value by adjusting the angle of the cylindrical rolling element between passes.

[0027] In step S3, a set of ultrasonic components is arranged every 100mm along the axial direction of the support frame, and an ultrasonic pressure head is arranged every 90° along the circumference of the support frame; the ultrasonic output power is 150W and the frequency is 20kHz.

[0028] The present invention has the following beneficial effects:

[0029] This invention leverages the high strength and corrosion resistance of titanium alloys and the lightweight and low cost of aluminum alloys. By machining threaded grooves on the inner surface of the outer titanium alloy layer and applying a high-energy ultrasonic field during the internal spinning process, plastic deformation is promoted, reducing residual stress within the titanium / aluminum composite shell. This results in the formation of a layered composite shell component with a low-stress, mechanically interlocked three-dimensional interface between the titanium outer layer and the aluminum inner layer. This method offers advantages such as material savings, low cost, good formability, and three-dimensional mechanical interlocking of the titanium / aluminum interface. The advanced process makes it an ideal method for preparing high-performance layered composite tubes. Attached Figure Description

[0030] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of the machining of a titanium alloy outer cylinder or an aluminum alloy inner cylinder on a lathe.

[0032] Figure 2 This is a schematic diagram of the titanium alloy outer cylinder.

[0033] Figure 3 for Figure 2 Enlarged image;

[0034] Figure 4 This is a schematic diagram of the aluminum alloy inner cylinder.

[0035] Figure 5 A schematic diagram of the spin forming process for a high-energy ultrasonic-assisted titanium / aluminum composite shell;

[0036] Figure 6 This is a schematic diagram of the spinning head structure;

[0037] Figure 7 This is a schematic diagram of the titanium / aluminum composite shell.

[0038] In the diagram: 101-Lathe bed; 102-Lathe legs; 103-Lathe headstock; 104-Change gearbox; 105-Feed gearbox; 106-Control lever; 107-Feed rod; 108-Lead screw; 109-Lathe guideway; 110-Tailstock; 111-Headstock speed change lever; 112-Lathe chuck; 113-Feed gearbox control lever; 114-Apron; 115-Saddle; 116-Apron control lever; 117-Slide plate; 118-Tool post; 119-Lathe tool;

[0039] 201-Internal spinning press frame; 202-Internal spinning press guide rail; 203-Internal spinning press spindle box; 204-Internal spinning press spindle; 205-Internal spinning press chuck; 206-Support frame; 207-Ultrasonic power supply; 208-Sliding frame; 209-Spinning shaft; 210-Hydraulic cylinder; 211-Ultrasonic pressure head; 212-Spinning head inner ring; 213-Cylindrical rolling element; 214-Cage; 215-Washer; 216-Locking nut; 217-First electrical control cabinet; 218-Second electrical control cabinet; 219-First electrical control cabinet power switch; 220-First electrical control cabinet power indicator light; 221-Spindle control switch; 222- 223-Spindle control switch indicator light; 224-Ultrasonic power switch; 225-Ultrasonic power indicator light; 226-Ultrasonic power control knob; 227-Ultrasonic amplitude control knob; 228-Ultrasonic amplitude control indicator light; 229-First display screen; 230-Spinning machine power switch; 231-Spinning machine power switch indicator light; 232-Speed ​​controller; 233-Speed ​​controller indicator light; 234-Pressure controller; 235-Pressure controller indicator light; 236-Temperature controller; 237-Temperature controller indicator light; 238-Second display screen; 239-Terminal terminal;

[0040] 301 - Titanium alloy outer cylinder; 302 - Aluminum alloy inner cylinder. Detailed Implementation

[0041] The technical solution of the present invention will now be clearly and completely described 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.

[0042] This embodiment provides a method for forming a titanium / aluminum layered composite shell. Titanium alloy is used as the outer layer material and aluminum alloy as the inner layer material. The titanium (outer) / aluminum (inner) layered composite shell is prepared by an internal spinning forming method. During the forming process, a threaded groove structure is machined on the inner surface of the outer titanium alloy shell. The aluminum alloy is then plastically deformed and filled into the threaded grooves on the inner surface of the titanium alloy through internal spinning, forming an interlocking three-dimensional interface at the titanium-aluminum interface, thus improving the interfacial shear strength. Simultaneously, high-energy ultrasonic waves are applied to the outer surface of the titanium alloy layers during the internal spinning process to reduce deformation resistance and promote plastic deformation of the inner and outer metal layers. After spinning is completed, ultrasonic waves are continued to be applied to control the residual stress inside the composite shell, achieving the preparation of a low-stress layered composite shell. This method is a practical and feasible preparation method for producing high-performance layered composite shells.

[0043] The raw materials used are: titanium alloy tubes, aluminum alloy tubes, sandpaper, and alcohol. The quantities used are as follows, measured in pieces, millimeters, and sheets.

[0044]

[0045] Machining is performed using a lathe, and the product is spun using an internal spinning press.

[0046] The lathe includes a bed 101, bed legs 102 for supporting the bed 101, a lathe headstock 103, a change gear box 104, a feed box 105, a control lever 106, a guide rod 107, a leadscrew 108, a lathe guide rail 109, and a tailstock 110. The lathe headstock 103 is equipped with a headstock speed change control lever 111 and a lathe chuck 112. The feed box 105 is equipped with a feed box control lever 113. The apron 114 is slidably connected to the lathe guide rail 109 via a saddle 115. The apron 114 is equipped with an apron control lever 116 and a middle slide 117. The middle slide 117 is equipped with a tool post 118, and a cutting tool 119 is mounted on the tool post 118.

[0047] The internal spinning press includes an internal spinning press frame 201, an internal spinning press guide rail 202, an internal spinning press spindle box 203, an internal spinning press spindle 204, an internal spinning press chuck 205, a support frame 206, an ultrasonic component, an ultrasonic power supply 207, a sliding frame 208, a spinning shaft 209, a spinning head, and a hydraulic cylinder 210; the internal spinning press spindle box 203, support frame 206, and sliding frame 208 are sequentially arranged on the internal spinning press frame 201; the sliding frame 209... 8. The internal spinning press is mounted on the internal spinning press frame 201 via the internal spinning press guide rail 202; the internal spinning press spindle 204 is driven to rotate by the internal spinning press spindle box 203, and the internal spinning press chuck 205 is mounted on the output end; the support frame 206 is coaxially arranged with the internal spinning press chuck 205; the ultrasonic components are arranged at preset intervals along the axial direction of the support frame 206, and each group of ultrasonic components includes multiple ultrasonic pressure heads 211 arranged circumferentially along the support frame 206; the ultrasonic pressure heads 211 The structure is arc-shaped to ensure good contact with the outer surface of the support frame 206; the ultrasonic power supply 207 provides power to the ultrasonic pressing head 211; the spinning shaft 209 is mounted on the sliding frame 208 and is coaxially arranged with the inner spinning machine chuck 205, and is driven by the hydraulic cylinder 210 to move axially; the spinning head includes a spinning head inner ring 212, cylindrical rolling elements 213 and a retainer 214; the spinning head inner ring 212 has a frustum-shaped structure, and its central hole is rotatably connected to the spinning shaft 209. The small end face faces the support frame 206, and the large end face faces the sliding frame 208; the cylindrical rolling element 213 surrounds the outer side of the inner ring 212 of the spinning head, and the central axis is parallel to the outer wall of the inner ring 212 of the spinning head; the retainer 214 passes through the cylindrical rolling element 213, and its two ends are respectively connected to the outer wall of the inner ring 212 of the spinning head and the spinning shaft 209; the spinning shaft 209 is provided with a threaded section, and a washer 215 and a locking nut 216 are fitted on the threaded section to press the retainer 214.

[0048] The aforementioned internal spinning press is controlled by the first electrical control cabinet 217 and the second electrical control cabinet 218.

[0049] The first electrical control cabinet 217 is equipped with a first electrical control cabinet power switch 219, a first electrical control cabinet power indicator light 220, a spindle control switch 221, a spindle control switch indicator light 222, an ultrasonic power switch 223, an ultrasonic power indicator light 224, an ultrasonic power control knob 225, an ultrasonic power control indicator light 226, an ultrasonic amplitude control knob 227, an ultrasonic amplitude control indicator light 228, and a first display screen 229.

[0050] The second electrical control cabinet 218 is equipped with a spinning machine power switch 230, a spinning machine power switch indicator light 231, a speed controller 232, a speed controller indicator light 233, a pressure controller 234, a pressure controller indicator light 235, a temperature controller 236, a temperature controller indicator light 237, and a second display screen 238.

[0051] The ultrasonic pressure head 211 is connected to the terminal block 239 on the first electrical control cabinet 217 via a wire.

[0052] The forming method of the above-mentioned titanium / aluminum layered composite shell includes the following steps.

[0053] S1, with titanium alloy outer cylinder 301 and aluminum alloy inner cylinder 302

[0054] The machining steps of the titanium alloy outer cylinder 301 are as follows: the titanium alloy outer cylinder 301 is clamped on the lathe through the lathe chuck 112, and the inner surface is machined by turning. The inner diameter is 100mm, the upper deviation is 0.1mm, and the lower deviation is 0.

[0055] Internal thread grooves are machined on the inner surface of the titanium alloy outer cylinder 301. The feed box control lever 113 is adjusted according to the pitch of the titanium alloy outer cylinder 301, the machine is started, the internal thread cutting tool 119 is selected, the tool is set, and cutting begins. According to different interface shear strength requirements, the depth of the thread groove is 0.1 to 0.5 mm, and the pitch is 4 mm.

[0056] The machining steps of the aluminum alloy inner cylinder 302 are as follows: the aluminum alloy inner cylinder 302 is clamped on the lathe through the lathe chuck 112, the outer surface is machined, the outer diameter is 100mm, the upper deviation is 0.05mm, the lower deviation is 0.15mm, and a step is machined at the first end, with an outer diameter of 104mm and a thickness of 3mm.

[0057] The inner surface of the aluminum alloy inner cylinder 302 is machined to an inner diameter of 94mm, with an upper deviation of 0.1mm and a lower deviation of 0.

[0058] S2, the aluminum alloy inner cylinder 302 is assembled into the titanium alloy outer cylinder 301 to form a titanium / aluminum assembly. The step at the first end of the aluminum alloy inner cylinder 302 presses against the first end of the titanium alloy outer cylinder 301 for positioning, while preventing coolant from entering the connection interface and affecting the interface connection performance.

[0059] S3, High-energy ultrasonic-assisted spinning forming of titanium / aluminum composite shell

[0060] t1, install the titanium / aluminum assembly prepared in step S2 into the support frame 206, and clamp the second end onto the chuck 205 of the internal spinning press, so that the center line of the titanium / aluminum assembly coincides with the center line of the main shaft 204 of the internal spinning press. After adjustment, position and clamp the titanium / aluminum assembly.

[0061] t2, turn on the spindle box 203, ultrasonic pressure head 211, and hydraulic cylinder 210 of the internal spinning press to make the titanium / aluminum assembly rotate, the spinning shaft 209 feeds axially, and the cylindrical rolling body 213 spins the titanium / aluminum assembly while performing ultrasonic vibration. After spinning ends, continue to apply ultrasonic vibration to adjust the internal residual stress of the titanium / aluminum composite shell. After adjustment, turn off the ultrasonic pressure head 211 and remove the titanium / aluminum composite shell formed by internal spinning.

[0062] Multi-pass forming is adopted, with single-pass spinning deformation amount less than 15%. The total spinning deformation amount reaches the preset value by adjusting the angle of the cylindrical rolling element 213 between passes.

[0063] An ultrasonic component is arranged every 100mm along the axial direction of the support frame 206, and an ultrasonic pressure head is arranged every 90° along the circumference of the support frame 206, for a total of 4 components; the ultrasonic output power is 150W and the frequency is 20kHz.

[0064] S4. Place the spun titanium / aluminum composite shell on a lathe and clamp it in place by the lathe chuck 112. Machin the outer surface of the titanium / aluminum composite shell. After machining, remove the titanium / aluminum composite shell.

[0065] S5, storage

[0066] The prepared titanium / aluminum composite shell should be packaged with soft material and stored in a clean, dry environment, protected from moisture, sunlight, and acid, alkali, and salt corrosion. The storage temperature should be 20℃ and the relative humidity ≤10%.

[0067] Conclusion: A titanium / aluminum composite shell was prepared by internal spinning forming, with titanium alloy as the outer layer and aluminum alloy as the inner layer. Threaded grooves were machined on the inner surface of the outer titanium alloy layer. An ultrasonic energy field was applied during the spinning process to improve the plastic deformation capacity of the aluminum alloy and simultaneously control the residual stress inside the composite shell. This resulted in a three-dimensional interface connection structure with low residual stress and mechanical interlocking, improving the shear bond strength of the interface and obtaining a titanium / aluminum composite shell that combines the properties of both titanium and aluminum alloys.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for forming a titanium / aluminum layered composite shell, characterized in that, Includes the following steps: S1, machining titanium alloy outer cylinder and aluminum alloy inner cylinder The titanium alloy outer cylinder and the aluminum alloy inner cylinder are machined to the preset dimensions. Threaded grooves are machined on the inner surface of the titanium alloy outer cylinder, and a step is machined at the first end of the aluminum alloy inner cylinder. S2, assemble the aluminum alloy inner cylinder into the titanium alloy outer cylinder, and press the first end of the aluminum alloy inner cylinder against the first end of the titanium alloy outer cylinder to form a titanium / aluminum assembly. S3, High-energy ultrasonic-assisted spinning forming of titanium / aluminum composite shell The titanium / aluminum assembly prepared in step S2 is mounted on an internal spinning press and spun into shape while being subjected to ultrasonic vibration. After spinning is completed, ultrasonic vibration is continued to be applied to regulate the internal residual stress of the titanium / aluminum composite shell. The internal spinning press used in step S3 includes an internal spinning press frame, an internal spinning press spindle box, an internal spinning press spindle, an internal spinning press chuck, a support frame, an ultrasonic component, an ultrasonic power supply, a sliding frame, a spinning shaft, a spinning head, and a hydraulic cylinder. The spindle box, support frame, and sliding frame of the internal spinning press are sequentially arranged on the frame of the internal spinning press. The main shaft of the internal spinning press is driven to rotate by the internal spinning press main shaft box, and an internal spinning press chuck is installed on the output end; The support frame is coaxially arranged with the chuck of the internal spinning press; The ultrasonic components are arranged at a preset interval along the axial direction of the support frame, and each group of ultrasonic components includes multiple ultrasonic pressure heads arranged circumferentially along the support frame. The ultrasonic power supply provides power to the ultrasonic indenter; The spinning shaft is mounted on the sliding frame and is coaxially arranged with the chuck of the inner spinning press. It is driven by a hydraulic cylinder to move axially. The spinning head includes a spinning head inner ring, cylindrical rolling elements, and a cage; The inner ring of the spinning head has a frustum-shaped structure, with the central hole rotatably connected to the spinning shaft. The small end face faces the support frame, and the large end face faces the sliding frame. The cylindrical rolling element surrounds the outer side of the inner ring of the spinning head, and the central axis is parallel to the outer wall of the inner ring of the spinning head. The cage passes through the cylindrical rolling element, and its two ends are respectively connected to the outer wall of the inner ring of the spinning head and the spinning shaft; The spinning shaft is provided with a threaded section; A washer and a lock nut are fitted onto the threaded section of the spinning shaft to compress and retain the cage; Step S3 includes: t1, Install the titanium / aluminum assembly in the support frame, and clamp the second end onto the chuck of the internal spinning press, so that the center line of the titanium / aluminum assembly coincides with the center line of the main shaft of the internal spinning press. After adjustment, position and clamp the titanium / aluminum assembly. t2, open the spindle box, ultrasonic press head, and hydraulic cylinder of the internal spinning press to make the titanium / aluminum assembly rotate, the spinning shaft is fed axially, and the cylindrical rolling body spins the titanium / aluminum assembly while performing ultrasonic vibration.

2. The method for forming the titanium / aluminum layered composite shell according to claim 1, characterized in that, The internal spinning press also includes an internal spinning press guide rail; The internal spinning press guide rail is mounted on the internal spinning press frame; The sliding frame is mounted on the guide rail of the internal spinning press.

3. The method for forming the titanium / aluminum layered composite shell according to claim 2, characterized in that, The internal spinning press is controlled by an electrical control cabinet.

4. The method for forming the titanium / aluminum layered composite shell according to any one of claims 1-3, characterized in that, In step S1, the machining steps of the titanium alloy outer cylinder are as follows: the titanium alloy outer cylinder is clamped on the lathe by the lathe chuck, and the inner surface is machined by turning. The inner diameter is 100mm, the upper deviation is 0.1mm, and the lower deviation is 0. An internal thread groove is machined on the inner surface of the titanium alloy outer cylinder. The depth of the thread groove is 0.1-0.5 mm and the pitch is 4 mm. The machining steps of the aluminum alloy inner cylinder are as follows: the aluminum alloy inner cylinder is clamped on the lathe by the lathe chuck, the outer surface is machined, the outer diameter is 100mm, the upper deviation is 0.05mm, the lower deviation is 0.15mm, and a step is machined at the first end, with an outer diameter of 104mm and a thickness of 3mm. The inner surface of the aluminum alloy inner cylinder is machined to an inner diameter of 94mm, with an upper deviation of 0.1mm and a lower deviation of 0.

5. The method for forming the titanium / aluminum layered composite shell according to claim 4, characterized in that, In step S3, multi-pass forming is adopted, with the single-pass spinning deformation amount being less than 15%. The total spinning deformation amount reaches the preset value by adjusting the angle of the cylindrical rolling element between passes.

6. The method for forming the titanium / aluminum layered composite shell according to claim 5, characterized in that, In step S3, a set of ultrasonic components is arranged every 100mm along the axial direction of the support frame, and an ultrasonic pressure head is arranged every 90° along the circumference of the support frame. The ultrasonic output power is 150W and the frequency is 20kHz.

7. The method for forming the titanium / aluminum layered composite shell according to claim 6, characterized in that, The process includes step S4, in which the spun titanium / aluminum composite shell is placed on a lathe, clamped by the lathe chuck, and the outer surface of the titanium / aluminum composite shell is machined. After machining, the titanium / aluminum composite shell is removed.

8. The method for forming the titanium / aluminum layered composite shell according to claim 7, characterized in that, Including step S5, storage Storage temperature: 20℃, relative humidity: ≤10%.

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