High-strength aluminum-lithium alloy friction stir deposition additive manufacturing and multi-stage heat treatment method

Abstract

The invention provides a high-strength aluminum lithium alloy friction stir deposition additive manufacturing and multi-stage heat treatment method, and relates to the related technical field of aluminum alloy friction stir deposition additive manufacturing. The method comprises the steps that a base plate is fixed, and a stirring head is arranged in a to-be-added area of the base plate; the base metal is loaded into a stirring head; a program is started, the ejector rod slowly pushes the aluminum-lithium alloy base material to a to-be-added material area, and when the aluminum-lithium alloy base material reaches a thermoplastic state, the stirring head advances to complete deposition; the stirring head is lifted up, the height of the end face of the stirring head and the deposition layer is adjusted, material adding in the opposite direction is conducted, and deposition is completed; the deposition step is repeated, upward layer-by-layer deposition is conducted till the height of a deposition layer reaches the target height, and the friction stir deposition additive component is obtained; according to the method, low-temperature solid solution and first aging treatment are firstly carried out on the friction stir deposition additive component, then high-temperature solid solution and second aging treatment are carried out, the high-strength aluminum-lithium alloy is obtained, and the problems that an oversized and medium-complex aluminum-lithium alloy structural component is difficult to form and prone to cracking are effectively solved.

Description

Technical Field

[0001] The present invention belongs to the technical field related to aluminum alloy stir friction deposition additive manufacturing, and specifically relates to a high-strength aluminum-lithium alloy stir friction deposition additive manufacturing and multi-stage heat treatment method. Background Art

[0002] To improve the effective carrying capacity of launch vehicles, there is an urgent need to lightweight rocket body structural components. The use of lightweight, high-performance materials is a key approach to achieving this. Compared to conventional aluminum alloys such as 2A14, 2024, and 2219, aluminum-lithium alloys offer lighter weight and higher strength, enabling greater lightweighting of rocket body structural components.

[0003] Traditional methods for manufacturing structural components include casting, forging, and machining. However, the difficulty in preparing oversized 2195 aluminum-lithium alloy ingots and producing homogeneous forgings makes the integrated production of oversized 2195 aluminum-lithium alloy structural components an international challenge. Therefore, there is an urgent need to develop new technologies for the integrated forming of oversized aluminum-lithium alloy structural components. Friction stir deposition additive manufacturing (FSAM) technology offers a new approach for the efficient and flexible production of large-scale aluminum-lithium alloy structural components.

[0004] However, the poor formability of aluminum-lithium alloys poses challenges in the stable forming of aluminum-lithium alloys by friction stir deposition additive manufacturing (FSAM). Furthermore, aluminum alloys prepared under dynamic thermomechanical coupling are prone to abnormal grain growth during subsequent heat treatment, significantly degrading the material's strength and toughness. Therefore, there is an urgent need to explore methods for the FSD AM and multi-stage heat treatment of high-strength aluminum-lithium alloys.

[0005] Patent document CN115519136A provides an additive manufacturing device and a solid-phase additive manufacturing method for hollow parts. The device comprises a feed tool, a tool head, a mold, and a base, which together form a variable-volume mold cavity. The lower portion of the feed tool protrudes downward relative to the bottom end of the tool head. The feed tool is a hollow structure, and the sidewall of the feed tool is provided with a discharge channel, which communicates with the mold cavity. The method comprises feeding powdered material into the mold cavity, controlling the rotation of the base, controlling the rotation of the tool head and axially moving it downward under the action of a forging force, and the powdered material flowing out of the discharge channel spreads along the bottom end of the tool head and is deposited on the upper surface of the base. However, patent document CN115519136A makes it difficult to prepare large-scale, high-performance aluminum-lithium alloy solid structural parts, such as rocket connecting rings. Summary of the Invention

[0006] In view of the defects in the prior art, the purpose of the present invention is to provide a high-strength aluminum-lithium alloy stir friction deposition additive manufacturing and multi-stage heat treatment method.

[0007] According to the present invention, a high-strength aluminum-lithium alloy friction stir deposition additive manufacturing and multi-stage heat treatment method is provided, comprising: Step S1, preparing a substrate and an aluminum-lithium alloy parent material; Step S2, fixing the substrate, placing a stirring head on the area of ​​the substrate to be added material, and adjusting the distance between the end face of the stirring head and the substrate; Step S3, loading the base material into the hollow stirring head, and setting the rotation speed, travel speed of the stirring head and the feeding speed of the aluminum-lithium alloy base material in the program; Step S4, starting the program, the stirring head starts to rotate, and the push rod slowly pushes the aluminum-lithium alloy base material to the area to be added. When the aluminum-lithium alloy base material reaches a thermoplastic state, the stirring head starts to move forward according to the set program to complete the deposition of the first layer of the deposition layer; Step S5, the stirring head is lifted, and the height between the end face of the stirring head and the deposited layer is adjusted to perform material addition in the reverse direction to complete the deposition of the second layer of the deposited layer; Step S6, repeating steps S3 to S5, depositing layer by layer upward until the height of the deposited layer reaches the target height, thereby obtaining a friction stir deposition additive component; Step S7: firstly subjecting the friction stir deposition additive component to a low-temperature solid solution treatment and a first aging treatment, and then subjecting the component to a high-temperature solid solution treatment and a second aging treatment to obtain a high-strength aluminum-lithium alloy.

[0008] Preferably, the aluminum-lithium alloy base material is an Al-Cu-Li alloy.

[0009] Preferably, the diameter of the aluminum-lithium alloy base material is 10 to 15 mm.

[0010] Preferably, the rotation speed of the stirring head is 380-500 r / min, the travel speed is 180-220 mm / min, the feeding speed of the aluminum-lithium alloy base material is 70-100 mm / min, and the interlayer lifting amount is 1-2 mm.

[0011] Preferably, the actual height of the deposited layer in each deposition is 2-3 mm.

[0012] Preferably, the low-temperature solution temperature is 400-460° C., and the time is 2-6 hours.

[0013] Preferably, the temperature of the first aging treatment is 165-175° C., and the time is 12-24 hours.

[0014] Preferably, the high-temperature solution temperature is 480-520° C., and the time is 0.5-2 h.

[0015] Preferably, the temperature of the second aging treatment is 170-175° C., and the time is 24-36 hours.

[0016] The present application also provides a high-strength aluminum-lithium alloy, which is made using any of the methods described above.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. The high-strength aluminum-lithium alloy friction stir deposition additive manufacturing method provided by the present invention can achieve stable forming of Al-Cu-Li alloy; 2. The multi-stage heat treatment method provided by the present invention releases strain energy and forms second-phase particles with pinning effect inside the structure through low-temperature solid solution and first aging treatment. After high-temperature short-time treatment and second aging treatment, abnormal grain growth is effectively suppressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Other features, objects and advantages of the present invention will become more apparent upon reading the detailed description of non-limiting embodiments with reference to the following drawings: Figure 1 Schematic diagram of the structure of friction stir deposition additive manufacturing in Example 1; Figure 2 This is a macroscopic photograph of the 2195 aluminum-lithium alloy after friction stir deposition additive manufacturing in Example 1; Figure 3 This is the metallographic structure after low-temperature solution aging + high-temperature solution aging in Example 1; Figure 4 This is the metallographic structure after low-temperature solid solution + high-temperature solid solution aging in Comparative Example 1; Figure 5 This is the metallographic structure after high temperature solution aging in Comparative Example 2; Figure 6 This is a comparison chart of the hardness of the component after multi-stage heat treatment in Example 1 and the hardness of the T8 state 2195 aluminum-lithium alloy base material; Figure 7 Schematic diagram of the process of friction stir deposition additive manufacturing and multi-stage heat treatment in the embodiment.

[0019] The figure shows: a substrate 1, a deposited layer 2, a stirring head 3, an aluminum-lithium alloy base material 4, a first forward direction 501, and a second forward direction 502. DETAILED DESCRIPTION

[0020] The present invention will be described in detail below with reference to specific embodiments. The following examples will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those skilled in the art, several changes and improvements can be made without departing from the scope of the present invention. These all fall within the scope of protection of the present invention.

[0021] This embodiment provides a high-strength aluminum-lithium alloy friction stir deposition additive manufacturing and multi-stage heat treatment method, such as Figure 7 As shown, the following steps are included: Step S1, preparing a substrate 1 and an aluminum-lithium alloy base material 4; Step S2, fixing the substrate 1, placing the stirring head 3 on the area of ​​the substrate 1 to be added, and adjusting the distance between the end face of the stirring head 3 and the substrate; Step S3, loading the aluminum-lithium alloy base material 4 into the hollow stirring head 3, and setting the rotation speed and travel speed of the stirring head 3 and the feeding speed of the aluminum-lithium alloy base material 4 in the program; Step S4, starting the program, the stirring head 3 starts to rotate, and the push rod slowly pushes the aluminum-lithium alloy base material 4 to the area to be added. When the aluminum-lithium alloy base material 4 reaches a thermoplastic state, the stirring head 3 starts to move forward according to the set program to complete the deposition of the first layer of the deposition layer; Step S5: the stirring head 3 is lifted, and the height between the end face of the stirring head 3 and the deposition layer is adjusted to perform material addition in the reverse direction to complete the deposition of the second layer of the deposition layer; Step S6, repeating steps S3 to S5, depositing layer by layer upward until the height of the deposited layer reaches the target height, thereby obtaining a friction stir deposition additive component; In step S7, the FSD component is first subjected to a low-temperature solution treatment and a first aging treatment, followed by a high-temperature solution treatment and a second aging treatment, to obtain a high-strength aluminum-lithium alloy. The low-temperature solution treatment temperature is 400-460°C for 2-6 hours. The first aging treatment temperature is 165-175°C for 12-24 hours. The high-temperature solution treatment temperature is 480-520°C for 0.5-2 hours. The second aging treatment temperature is 170-175°C for 24-36 hours.

[0022] In one embodiment, the aluminum-lithium alloy matrix is ​​an Al-Cu-Li alloy.

[0023] In one embodiment, the diameter of the aluminum-lithium alloy base material is 10-15 mm.

[0024] In one embodiment, the rotation speed of the stirring head is 380-500 r / min, the travel speed is 180-220 mm / min, the feeding speed of the aluminum-lithium alloy base material is 70-100 mm / min, and the interlayer lifting amount is 1-2 mm.

[0025] The interlayer lifting amount is the distance between the end face of the stirring head 3 and the previous deposition layer.

[0026] In one embodiment, the actual height of the deposition layer during each deposition is 2-3 mm.

[0027] The high-strength aluminum-lithium alloy friction stir deposition additive manufacturing method provided in this embodiment can achieve stable forming of Al-Cu-Li alloys. The friction stir deposition additive manufacturing component undergoes multi-stage heat treatment. Through low-temperature solutionization and a first aging treatment, strain energy storage is released and second-phase particles with a pinning effect are formed within the structure. After a high-temperature, short-time treatment and a second aging treatment, abnormal grain growth is effectively suppressed. This effectively solves the problems of difficult forming and prone to cracking of ultra-large, moderately complex aluminum-lithium alloy structures, ultimately producing a high-strength aluminum-lithium alloy.

[0028] Example 1 like Figure 1 As shown, the aluminum-lithium alloy base material 4 is T8 state 2195 aluminum-lithium alloy with a diameter of 15 mm, the size of the additively manufactured structural part is 45 mm × 35 mm × 200 mm, the low-temperature solution temperature is 460 ° C, the time is 2 h, the aging temperature is 170 ° C, the time is 12 h; the high-temperature solution temperature is 520 ° C, the time is 0.5 h; the aging temperature is 175 ° C, and the time is 36 h.

[0029] Step S11: First, prepare substrate 1 as an O-state 2219 aluminum alloy substrate with a size of 400mm×400mm×25mm, use 1000# and 2000# sandpaper to polish the surface oxide of substrate 1 clean; then, wipe the surface of substrate 1 clean with alcohol.

[0030] Step S12: fix the substrate 1, place the stirring head 3 in the area to be added, and adjust the distance between the end face of the stirring head 3 and the substrate 1 to 1.5 mm.

[0031] Step S13: Place the 2195 Al-Li alloy base material 4 into the hollow stirring head 3 for later use. Set the rotation speed of the stirring head 3 to 430 r / min, the travel speed to 195 mm / min, and the feeding speed to 90 mm / min.

[0032] In step S14, the program is started, the stirring head 3 begins to rotate, and the push rod slowly pushes the aluminum-lithium alloy base material 4 to the area to be added. When the aluminum-lithium alloy base material 4 reaches a thermoplastic state, the stirring head 3 begins to advance in the set first forward direction 501, and the thermoplasticized 2195 aluminum alloy material is deposited on the surface of the substrate 1 by stirring friction to form a 2-3 mm deposition layer 2.

[0033] In step S15, the stirring head 3 is lifted, and the height between its end face and the first deposition layer is adjusted to 1.5 mm. The forward direction is adjusted to the opposite direction of the first forward direction 501 in step S4: the second forward direction 502. According to the set parameters, the thermoplasticized 2195 aluminum alloy material is deposited on the surface of the first deposition layer by stirring friction to form a 2-3 mm deposition layer 2.

[0034] Step S16, repeating steps S13 to S15 to perform layer-by-layer deposition until a friction stir deposition additive component (such as Figure 2 shown).

[0035] Step S17: After the deposition is completed, the substrate and the component are separated by wire cutting, and the FSD component is subjected to multi-stage heat treatment: Step S18: The friction stir deposition additive component in step S16, i.e., the aluminum-lithium alloy after the additive process is first subjected to low-temperature solid solution and aging treatment, and then subjected to high-temperature solid solution and aging treatment: 1) The friction stir deposition additive 2195 aluminum-lithium alloy component was subjected to low-temperature solution treatment at a temperature of 460°C for 2 hours, and then quenched in cold water; then the first aging treatment was performed at a temperature of 170°C for 12 hours, and the component was cooled in air after the aging treatment; 2) The components that have undergone low-temperature solution and aging treatment are subjected to high-temperature solution treatment at a temperature of 520°C for 0.5 h. After the solution treatment, they are quenched in cold water; then a second aging treatment is carried out at a temperature of 175°C for 36 h.

[0036] Its microstructure is Figure 3 As shown in the figure, the grain structure is small and uniform, and there are no abnormally grown grains.

[0037] like Figure 6 As shown in the figure, the hardness of the high-strength aluminum-lithium alloy obtained in Example 1 is compared with the hardness of the T8 state 2195 aluminum-lithium alloy base material. The average hardness of the 2195 aluminum-lithium alloy manufactured by friction stir deposition after heat treatment reaches 180.7HV, the average hardness of the T8 state 2195 aluminum-lithium alloy base material is 190.0HV, and the performance of the T6 state additively manufactured 2195 aluminum-lithium alloy reaches 95% of the base material alloy.

[0038] Example 1 solves the problem of difficult forming and easy cracking of ultra-large-sized, medium-complex aluminum-lithium alloy structural parts, and its performance is comparable to that of T8 aluminum-lithium alloy.

[0039] Comparative Example 1 The parent material alloy is T8 state 2195 aluminum-lithium alloy with a diameter of 15 mm. The size of the additively manufactured structural part is 45 mm × 35 mm × 200 mm. The low-temperature solution temperature is 460 ° C, the time is 2 h, the high-temperature solution temperature is 520 ° C, the time is 0.5 h; the aging temperature is 175 ° C, and the time is 36 h.

[0040] Step S21: First, prepare a substrate of O-state 2219 aluminum alloy substrate material with a size of 400mm×400mm×25mm, use 1000# and 2000# sandpaper to clean the oxide on the surface of the substrate; then, wipe the surface of the substrate clean with alcohol.

[0041] Step S22: fix the substrate, place the stirring head in the area to be added, and adjust the distance between the end face of the stirring head and the substrate to 1.5 mm; Step S23: Place the 2195 aluminum-lithium alloy base material into the hollow stirring head for standby use.

[0042] Step S24, setting the rotation speed of the stirring head to 430 r / min, the travel speed to 195 mm / min, and the feeding speed to 90 mm / min.

[0043] Step S25, start the program, the stirring head starts to rotate, and the push rod slowly pushes the aluminum-lithium alloy base material to the area to be added. When the aluminum-lithium alloy base material reaches a thermoplastic state, the stirring head starts to move forward according to the set program, and the thermoplasticized 2195 aluminum alloy material is deposited on the surface of the substrate by stirring friction to form a 2-3 mm deposition layer.

[0044] In step S26, the stirring head is raised, and the height between its end face and the first deposition layer is adjusted to 1.5 mm. The forward direction is adjusted to the opposite direction. According to the set parameters, the thermoplasticized 2195 aluminum alloy material is deposited on the surface of the first deposition layer by stirring friction to form a 2-3 mm deposition layer. According to this step, it is repeated and deposited layer by layer until a component with a size of 45 mm × 35 mm × 200 mm is prepared.

[0045] Step S27: After the deposition is completed, the substrate and the component are separated by wire cutting, and the stir friction deposition additive component is subjected to multi-stage heat treatment.

[0046] Step S28: The aluminum-lithium alloy after the addition in step S25 is first subjected to low-temperature solution treatment, and then subjected to high-temperature solution treatment and aging treatment: 1) The friction stir deposition additive 2195 aluminum-lithium alloy component was subjected to low-temperature solution treatment at 460°C for 2 h, and then quenched in cold water after the solution treatment; 2) The components that have undergone low-temperature solution treatment are subjected to high-temperature solution treatment at a temperature of 520°C for 0.5 h. After the solution treatment is completed, they are quenched in cold water; then aging treatment is carried out at a temperature of 175°C for 36 h. The microstructure is as follows: Figure 4 shown.

[0047] like Figure 4As shown in the figure, the phenomenon of abnormal grain growth occurs in Comparative Example 1, which significantly deteriorates the strength and toughness of the material. It is proved that the multi-stage heat treatment in Example 1 releases the strain energy storage, and the second phase particles with the effect of pinning the grain boundaries are formed inside the grains during the first aging treatment, which effectively suppresses the abnormal grain growth during the subsequent high-temperature short-time treatment. Although Comparative Example 1 relies on low-temperature solution heat treatment to release the strain energy storage inside the material, the effect is limited, and the lack of precipitation phases pinning the grain boundaries inside the grains leads to abnormal grain growth in the subsequent high-temperature solution heat treatment stage.

[0048] Comparative Example 2 The parent material alloy is T8 state 2195 aluminum-lithium alloy with a diameter of 15 mm. The size of the additively manufactured structural part is 45 mm × 35 mm × 200 mm. The high-temperature solution temperature is 520 ° C and the time is 0.5 h; the aging temperature is 175 ° C and the time is 36 h.

[0049] Step S31: First, prepare a substrate made of O-state 2219 aluminum alloy substrate material with a size of 400 mm × 400 mm × 25 mm, and use 1000# and 2000# sandpaper to clean the oxide on the substrate surface; then, wipe the substrate surface clean with alcohol; Step S32: fix the substrate, place the stirring head in the area to be added, and adjust the distance between the end face of the stirring head and the substrate to 1.5 mm; Step S33, placing the 2195 aluminum-lithium alloy base material into the hollow stirring head for standby use; Step S34, setting the rotation speed of the stirring head to 430 r / min, the travel speed to 195 mm / min, and the feeding speed to 90 mm / min; Step S35: Start the program, the stirring head begins to rotate, and the push rod slowly pushes the aluminum-lithium alloy base material to the area to be added. When the aluminum-lithium alloy base material reaches a thermoplastic state, the stirring head begins to advance according to the set program, and the thermoplasticized 2195 aluminum alloy base material is deposited on the substrate surface by stirring friction to form a 2-3 mm thick deposition layer; In step S36, the stirring head is raised, and the height between its end face and the first deposited layer is adjusted to 1.5 mm. The forward direction is adjusted to the opposite direction. According to the set parameters, the thermoplasticized 2195 aluminum alloy material is deposited on the surface of the first deposited layer by stirring friction to form a 2-3 mm thick deposited layer. This step is repeated and deposited layer by layer until a component with a size of 45 mm × 35 mm × 200 mm is prepared. Step S37: After the deposition is completed, the substrate and the component are separated by wire cutting, and the FSD component is heat treated: Step S38: subjecting the aluminum-lithium alloy after the addition in step S36 to high-temperature solid solution and aging treatment: The friction stir deposition additive 2195 aluminum-lithium alloy component was subjected to high-temperature solution treatment at a temperature of 520°C for 0.5 h, and then quenched in cold water after the solution treatment; then it was subjected to aging treatment at an aging temperature of 175°C for 36 h. The microstructure is shown in the figure. Figure 5 shown.

[0050] like Figure 5 As shown, the phenomenon of abnormal grain growth occurs in Comparative Example 2, which significantly deteriorates the strength and toughness of the material. It is proved that the multi-stage heat treatment in Example 1 releases strain energy storage, and second-phase particles with the effect of pinning grain boundaries are formed inside the grains during the first aging treatment, which effectively suppresses the abnormal growth of grains during subsequent high-temperature short-time treatment. Because the material undergoes severe plastic deformation during the forming process, a large number of dislocations and substructures are generated inside, which increases the driving force for grain growth and causes the grains to increase significantly. However, Comparative Example 2 directly subjects the deposited material to a high-temperature solution treatment, which lacks the steps of removing the strain energy storage inside the material and introducing pinning second-phase particles, which ultimately leads to significant grain growth.

[0051] In the description of this application, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0052] The above describes specific embodiments of the present invention. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art may make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. The embodiments of this application and the features in the embodiments may be combined with each other in any manner unless there is a conflict.

Claims

1. A high-strength aluminum-lithium alloy friction stir deposition additive manufacturing and multi-stage heat treatment method, characterized in that: include: Step S1, preparing a substrate (1) and an aluminum-lithium alloy base material (4); Step S2, fixing the substrate (1), placing a stirring head (3) on the area of ​​the substrate (1) to be added, and adjusting the distance between the end face of the stirring head (3) and the substrate (1); Step S3, loading the aluminum-lithium alloy base material (4) into the hollow stirring head (3), and setting the rotation speed and travel speed of the stirring head (3) and the feeding speed of the aluminum-lithium alloy base material (4) in the program; Step S4, starting the program, the stirring head (3) starts to rotate, and the push rod pushes the aluminum-lithium alloy base material (4) to the area to be added. When the aluminum-lithium alloy base material (4) reaches a thermoplastic state, the stirring head (3) starts to move forward according to the set program to complete the deposition of the first layer of the deposition layer (2); Step S5, the stirring head (3) is lifted, and the height between the end face of the stirring head (3) and the deposition layer is adjusted to perform material addition in the reverse direction to complete the second layer deposition of the deposition layer (2); Repeating steps S3 to S5, depositing upward layer by layer until the height of the deposition layer (2) reaches the target height, thereby obtaining a friction stir deposition additive component; Step S6: firstly subjecting the friction stir deposition additive component to a low-temperature solid solution treatment and a first aging treatment, and then subjecting the component to a high-temperature solid solution treatment and a second aging treatment to obtain a high-strength aluminum-lithium alloy.

2. The high-strength aluminum-lithium alloy friction stir deposition additive manufacturing and multi-stage heat treatment method according to claim 1, characterized in that: The aluminum-lithium alloy base material (4) is an Al-Cu-Li alloy.

3. The high-strength aluminum-lithium alloy friction stir deposition additive manufacturing and multi-stage heat treatment method according to claim 1, characterized in that: The diameter of the aluminum-lithium alloy base material (4) is 10 to 15 mm.

4. The high-strength aluminum-lithium alloy friction stir deposition additive manufacturing and multi-stage heat treatment method according to claim 1, characterized in that: The rotation speed of the stirring head (3) is 380-500 r / min, the travel speed is 180-220 mm / min, the feeding speed of the aluminum-lithium alloy base material (4) is 70-100 mm / min, and the interlayer lifting amount is 1-2 mm.

5. The high-strength aluminum-lithium alloy friction stir deposition additive manufacturing and multi-stage heat treatment method according to claim 1, characterized in that: The actual height of the deposited layer in each deposition is 2 to 3 mm.

6. The high-strength aluminum-lithium alloy friction stir deposition additive manufacturing and multi-stage heat treatment method according to claim 1, characterized in that: The low-temperature solution temperature is 400-460° C., and the time is 2-6 hours.

7. The high-strength aluminum-lithium alloy friction stir deposition additive manufacturing and multi-stage heat treatment method according to claim 1, characterized in that: The temperature of the first aging treatment is 165-175° C., and the time is 12-24 hours.

8. The high-strength aluminum-lithium alloy friction stir deposition additive manufacturing and multi-stage heat treatment method according to claim 1, characterized in that: Most high-temperature solution temperatures are 480-520°C, and the time is 0.5-2h.

9. The high-strength aluminum-lithium alloy friction stir deposition additive manufacturing and multi-stage heat treatment method according to claim 1, characterized in that: The temperature of the second aging treatment is 170-175° C., and the time is 24-36 hours.

10. A high-strength aluminum-lithium alloy, characterized in that: It is produced using the method according to any one of claims 1 to 9.

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