A method for improving the rolling quality of Ti2AlNb / high-strength aluminum alloy composite plates using a self-coating structure
By employing a self-encasing structure and a gradient platform design for sealing, the oxidation and cracking problems of Ti2AlNb-based alloy and high-strength aluminum alloy composite plates during the rolling process were solved, achieving high-quality composite plate rolling that meets the requirements of high temperature, high strength, and lightweight.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HARBIN INST OF TECH
- Filing Date
- 2024-01-23
- Publication Date
- 2026-06-26
AI Technical Summary
The existing Ti2AlNb-based alloy and high-strength aluminum alloy composite plates have an incompatible rolling temperature and deformation resistance during the rolling process, which leads to severe interface oxidation, easy cracking, and difficulty in achieving high-quality rolling.
The design employs a self-encasing structure, using a back plate and cover plate made of high-strength aluminum alloy to form a gradient platform design. Combined with sealing treatment and metastable heating, this ensures that the Ti2AlNb-based alloy is rolled within the high-strength aluminum alloy cladding, avoiding interface oxidation and enabling rolling under different temperature conditions.
It effectively inhibits the oxidation of the composite plate interface, ensures the high processing temperature of Ti2AlNb-based alloy, improves material utilization, and realizes the rolling and forming of high-strength and lightweight composite plates, which meets the needs of green development.
Smart Images
Figure CN117862245B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a method for improving the rolling quality of Ti2AlNb / high-strength aluminum alloy composite plates. Background Technology
[0002] The rapid development of supersonic and hypersonic vehicles, coupled with increasingly mature transonic maneuvering and hypersonic flight technologies, has led to short-duration Mach 6 flights becoming commonplace. However, the "thermal barrier effect" causes vehicle skin temperatures to exceed 700°C, resulting in stringent requirements such as short-duration high-temperature resistance, lightweight construction, and high strength. Single metals are no longer sufficient to meet these demands. Ti2AlNb-based alloys are a novel high-temperature resistant titanium-based alloy with service temperatures above 700°C, making them well-suited for the operational environment of hypersonic vehicle skins. However, their high density hinders weight reduction in the skin structure. Using Ti2AlNb / high-strength aluminum alloy composite plates could achieve lightweighting while maintaining high temperature resistance and strength. Currently, high-quality rolling of Ti2AlNb / high-strength aluminum alloy composite plates remains a challenge. There are two main reasons for this. First, the processing temperature of Ti2AlNb-based alloys is above 750℃, which is far higher than the rolling temperature of high-strength aluminum alloys. It is difficult to coordinate the rollable temperature and deformation resistance of Ti2AlNb-based alloys with those of high-strength aluminum alloys. Second, the severe oxidation that occurs at the interface between Ti2AlNb-based alloys and high-strength aluminum alloys during heating severely hinders interfacial bonding, leading to interfacial cracking. Summary of the Invention
[0003] This invention aims to address the problems of irreconcilable rolling temperatures and deformation resistance between existing Ti2AlNb matrix alloys and high-strength aluminum alloys, which lead to cracking and separation during composite plate rolling, as well as interface oxidation during pre-rolling heat treatment and rolling of Ti2AlNb / high-strength aluminum alloy composite plates. Furthermore, it provides a method for improving the rolling quality of Ti2AlNb / high-strength aluminum alloy composite plates using a self-encasing structure.
[0004] A method for improving the rolling quality of Ti2AlNb / high-strength aluminum alloy composite plates using a self-coating structure, comprising the following steps:
[0005] I. Self-encasing structure and preparation:
[0006] The back plate is made of high-strength aluminum alloy, and the cover plate is made of steel or high-strength aluminum alloy. The back plate and the cover plate form a self-enclosing structure.
[0007] The back plate has an upper platform and a bottom platform arranged in a gradient from the outside to the inside on one side surface, with the bottom platform located at the bottom center of the upper platform; the cover plate matches the upper platform.
[0008] II. Assembly:
[0009] The bottom platform of the back plate and the side of the Ti2AlNb-based alloy plate that contacts the bottom platform are ground and cleaned. Then the Ti2AlNb-based alloy plate is placed in the bottom platform of the back plate and the cover plate is put on to obtain the part to be rolled.
[0010] III. Composite Plate Rolling:
[0011] The workpiece is held at a temperature of 250℃~300℃, and then held at a temperature of 650℃~800℃. After holding, it is rolled with the roll temperature at room temperature, the rolling speed at 0.5m / min~5m / min, the total reduction at 30%~70%, and the number of rolling passes at 1~4. After rolling, it is heat-treated to obtain the rolled composite plate.
[0012] IV. Post-processing of composite panels:
[0013] The cover plate on the rolled composite plate is removed, and then the excess back plate on all four sides is cut off. This completes the method of improving the rolling quality of Ti2AlNb / high-strength aluminum alloy composite plate by utilizing the self-encasing structure.
[0014] The beneficial effects of this invention are:
[0015] This invention processes a softer, high-strength aluminum alloy into a self-encasing structure, encasing a harder Ti2AlNb-based alloy within the high-strength aluminum alloy casing. This suppresses interfacial oxidation, improves the coordinated deformation behavior of the two metals, and utilizes metastable heating to place the two alloys in different temperature states. After heat treatment, rolling is performed, thereby achieving high-quality rolling. This invention offers the following advantages:
[0016] 1. The self-encasing structure and sealing treatment greatly avoid oxidation of the composite plate joint surface during heat treatment and rolling. Brittle oxides generated during heat treatment can easily become crack initiation points during rolling. Oxides generated during rolling can hinder interfacial metallurgical bonding and reduce interfacial strength.
[0017] 2. Due to the high processing strength of Ti2AlNb-based alloys at room temperature, the Ti2AlNb / high-strength aluminum alloy composite plate must be heated to a temperature above 650℃ to ensure its forming. 650℃ exceeds the melting point of the high-strength aluminum alloy, which may melt. However, in this method, the heat treatment of the composite plate at 650℃ involves a short holding time, and due to the self-encasing structure of the high-strength aluminum alloy, it comes into contact with the rolls during rolling, causing its temperature to drop and preventing melting. The Ti2AlNb-based alloy, located inside the encasing structure and not in contact with the rolls, experiences a slower temperature drop, maintaining good deformability throughout the rolling process.
[0018] 3. The high-strength aluminum alloy self-encasing structure is itself part of the composite plate, improving material utilization and meeting the requirements of green development. Furthermore, this method also shows promise for preparing high-strength aluminum / Ti2AlNb / high-strength aluminum three-layer composite plates.
[0019] The above advantages demonstrate that this method can achieve high processing temperatures for Ti2AlNb-based alloys while ensuring that the high-strength aluminum alloy does not melt, thus matching the strength of the Ti2AlNb-based alloy with that of the high-strength aluminum alloy and making the rolling of the composite plate possible. Furthermore, through its self-encasing structure and sealing, it avoids interface oxidation of the composite plate while improving material utilization, ensuring high-quality rolling of the composite plate.
[0020] Instruction manual illustrations
[0021] Figure 1 This is a schematic diagram of the backplate structure described in step one of the present invention;
[0022] Figure 2 This is a schematic diagram of the cover plate structure described in step one of the present invention;
[0023] Figure 3 This is a schematic diagram of the Ti2AlNb-based alloy plate structure described in step two of this invention;
[0024] Figure 4 This is a schematic diagram of the assembly in step two of the present invention;
[0025] Figure 5 The image shows the physical specimen of the Ti2AlNb / high-strength aluminum alloy composite plate prepared in Example 1.
[0026] Figure 6 The image shows the actual Ti2AlNb / high-strength aluminum alloy composite plate prepared in Example 2.
[0027] Figure 7 This is a cross-sectional view of the Ti2AlNb / high-strength aluminum alloy composite plate prepared in Example 1;
[0028] Figure 8 The tensile stress-strain curve of the Ti2AlNb / high-strength aluminum alloy composite plate prepared in Example 1 at room temperature is shown.
[0029] Figure 9 The thickness distribution diagram is shown for the Ti2AlNb / high-strength aluminum alloy composite plate prepared in Example 1. Detailed Implementation
[0030] Specific implementation method one, combined with Figures 1 to 4 Detailed explanation: This embodiment describes a method for improving the rolling quality of Ti2AlNb / high-strength aluminum alloy composite plates using a self-coating structure. It is carried out according to the following steps:
[0031] I. Self-encasing structure and preparation:
[0032] The back plate is made of high-strength aluminum alloy, and the cover plate is made of steel or high-strength aluminum alloy. The back plate and the cover plate form a self-enclosing structure.
[0033] The back plate has an upper platform and a bottom platform arranged in a gradient from the outside to the inside on one side surface, with the bottom platform located at the bottom center of the upper platform; the cover plate matches the upper platform.
[0034] II. Assembly:
[0035] The bottom platform of the back plate and the side of the Ti2AlNb-based alloy plate that contacts the bottom platform are ground and cleaned. Then the Ti2AlNb-based alloy plate is placed in the bottom platform of the back plate and the cover plate is put on to obtain the part to be rolled.
[0036] III. Composite Plate Rolling:
[0037] The workpiece is held at a temperature of 250℃~300℃, and then held at a temperature of 650℃~800℃. After holding, it is rolled with the roll temperature at room temperature, the rolling speed at 0.5m / min~5m / min, the total reduction at 30%~70%, and the number of rolling passes at 1~4. After rolling, it is heat-treated to obtain the rolled composite plate.
[0038] IV. Post-processing of composite panels:
[0039] The cover plate on the rolled composite plate is removed, and then the excess back plate on all four sides is cut off. This completes the method of improving the rolling quality of Ti2AlNb / high-strength aluminum alloy composite plate by utilizing the self-encasing structure.
[0040] In this embodiment, when steel is selected as the material for the cover plate, the steel and the Ti2AlNb-based alloy are not metallurgically bonded, making it easier to remove in subsequent processing.
[0041] In this embodiment, the self-encased structure is prepared by additive manufacturing, specifically in the following ways: ① aluminum alloy laser additive manufacturing; ② aluminum alloy electric arc additive manufacturing; ③ aluminum alloy friction stir welding additive manufacturing.
[0042] In step two of this embodiment, the bottom platform of the high-strength aluminum alloy backplate is the intended bonding surface. This surface is polished and cleaned sequentially with alcohol and acetone. The intended bonding surface of the Ti2AlNb-based alloy plate is also polished until the oxide layer is removed, and then cleaned sequentially with alcohol and acetone.
[0043] The beneficial effects of this embodiment are:
[0044] This embodiment processes a softer high-strength aluminum alloy into a self-sheathing structure, encasing a harder Ti2AlNb-based alloy within the high-strength aluminum alloy sheath. This suppresses interfacial oxidation, improves the coordinated deformation behavior of the two metals, and utilizes metastable heating to place the two alloys in different temperature states. After heat treatment, rolling is performed, thereby achieving high-quality rolling. This has the following advantages:
[0045] 1. The self-encasing structure and sealing treatment greatly avoid oxidation of the composite plate joint surface during heat treatment and rolling. Brittle oxides generated during heat treatment can easily become crack initiation points during rolling. Oxides generated during rolling can hinder interfacial metallurgical bonding and reduce interfacial strength.
[0046] 2. Due to the high processing strength of Ti2AlNb-based alloys at room temperature, the Ti2AlNb / high-strength aluminum alloy composite plate must be heated to a temperature above 650℃ to ensure its forming. 650℃ exceeds the melting point of the high-strength aluminum alloy, which may melt. However, in this method, the heat treatment of the composite plate at 650℃ involves a short holding time, and due to the self-encasing structure of the high-strength aluminum alloy, it comes into contact with the rolls during rolling, causing its temperature to drop and preventing melting. The Ti2AlNb-based alloy, located inside the encasing structure and not in contact with the rolls, experiences a slower temperature drop, maintaining good deformability throughout the rolling process.
[0047] 3. The high-strength aluminum alloy self-encasing structure is itself part of the composite plate, improving material utilization and meeting the requirements of green development. Furthermore, this method also shows promise for preparing high-strength aluminum / Ti2AlNb / high-strength aluminum three-layer composite plates.
[0048] The above advantages demonstrate that this method can achieve high processing temperatures for Ti2AlNb-based alloys while ensuring that the high-strength aluminum alloy does not melt, thus matching the strength of the Ti2AlNb-based alloy with that of the high-strength aluminum alloy and making the rolling of the composite plate possible. Furthermore, through its self-encasing structure and sealing, it avoids interface oxidation of the composite plate while improving material utilization, ensuring high-quality rolling of the composite plate.
[0049] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that the high-strength aluminum alloy mentioned in step one is a 2-series high-strength aluminum alloy or a 7-series high-strength aluminum alloy. Everything else is the same as in Specific Implementation Method One.
[0050] Specific Implementation Method Three: This implementation method differs from Specific Implementation Method One or Two in that: the area of the bottom platform in step one is smaller than that of the upper platform; the Ti2AlNb-based alloy plate in step two matches the bottom platform in step one; and the end of the back plate in step one that first enters the rolling mill is ground with a bevel. Everything else is the same as in Specific Implementation Method One or Two.
[0051] In this specific embodiment, a bevel is ground on the end of the high-strength aluminum alloy back plate that preferentially enters the rolling mill, so that it can enter the rolling mill better.
[0052] Specific Implementation Method Four: This implementation method differs from Specific Implementation Methods One to Three in that: the upper platform and the bottom platform, which are sequentially gradient-set from the outside to the inside on one side surface of the back plate in step one, are specifically prepared according to the following steps: First, a groove is machined into one side surface of the back plate to form the bottom platform, and then a step with a width of 10mm to 15mm is machined along the upper edge of the bottom platform to form the upper platform. Everything else is the same as in Specific Implementation Methods One to Three.
[0053] Specific Implementation Method Five: This implementation method differs from Specific Implementation Methods One to Four in that the Ti2AlNb-based alloy plate mentioned in step two is Ti-22Al-25Nb, Ti-23Al-17Nb, Ti-25Al-24Nb, or Ti-22Al-27Nb. Everything else is the same as in Specific Implementation Methods One to Four.
[0054] Specific Implementation Method Six: This implementation method differs from Specific Implementation Methods One to Five in that: in step two, a cover plate is placed and sealed; the sealing process involves applying high-temperature sealant or vacuum welding. Everything else is the same as in Specific Implementation Methods One to Five.
[0055] This specific embodiment seals the interface between the cover plate and the back plate, thus not affecting the intended bonding surface between the high-strength aluminum alloy and the Ti2AlNb-based alloy. Sealing the bonding surface would impede the flow of the Ti2AlNb-based alloy and the high-strength aluminum alloy at the interface, potentially causing tearing during the composite plate rolling process.
[0056] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Methods One to Six in that a graphite sheet is placed between the Ti2AlNb-based alloy plate and the cover plate in step two. Everything else is the same as in Specific Implementation Methods One to Six.
[0057] In this specific embodiment, a graphite sheet is placed between the Ti2AlNb-based alloy and the high-strength aluminum alloy cover plate, followed by sealing. The graphite sheet hinders the metallurgical bonding between the Ti2AlNb-based alloy and the cover plate, making it easier to remove the cover plate in subsequent processing.
[0058] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Methods One to Seven in that the heat treatment described in step three is specifically carried out as follows: Under vacuum conditions and a temperature of 100℃~200℃, the temperature is maintained for 30min~60min. Everything else is the same as in Specific Implementation Methods One to Seven.
[0059] Specific Implementation Method Nine: This implementation method differs from Specific Implementation Methods One to Eight in that: after heat preservation in step three, rolling is performed within 30 seconds. Everything else is the same as Specific Implementation Methods One to Eight.
[0060] Specific Implementation Method Ten: This implementation method differs from Specific Implementation Methods One to Nine in that: in step three, the workpiece to be rolled is held at a temperature of 250℃~300℃ for 20min~30min, and then held at a temperature of 680℃~720℃ for 2min~5min. Everything else is the same as in Specific Implementation Methods One to Nine.
[0061] The beneficial effects of the present invention are verified using the following embodiments:
[0062] Example 1:
[0063] A method for improving the rolling quality of Ti2AlNb / high-strength aluminum alloy composite plates using a self-coating structure, comprising the following steps:
[0064] I. Self-encasing structure and preparation:
[0065] The back plate is made of high-strength aluminum alloy, and the cover plate is made of steel or high-strength aluminum alloy. The back plate and the cover plate form a self-enclosing structure.
[0066] The back panel has an upper platform and a bottom platform arranged in a gradient from the outside to the inside on one side surface, with the bottom platform located at the bottom center of the upper platform; the cover plate matches the upper platform, the total thickness of the back panel is 5mm, and the thickness of the cover plate is 1mm.
[0067] II. Assembly:
[0068] The bottom platform of the back plate and the surface of the Ti2AlNb-based alloy plate that is in contact with the bottom platform are polished and cleaned with alcohol and acetone. Then the Ti2AlNb-based alloy plate is placed in the bottom platform of the back plate, covered with a cover plate and sealed to obtain the part to be rolled.
[0069] III. Composite Plate Rolling:
[0070] The workpiece is held at 300℃ for 20 minutes, then at 680℃ for 3 minutes. After holding, it is rolled within 30 seconds. The roll temperature is room temperature, the rolling speed is 1 m / min, the reduction is 30%, and the rolling pass is 1. After rolling, it is heat treated to obtain the rolled composite plate.
[0071] IV. Post-processing of composite panels:
[0072] The cover plate on the rolled composite plate is removed, and then the excess back plate on all four sides is cut off to obtain the Ti2AlNb / high-strength aluminum alloy composite plate. This completes the method of improving the rolling quality of Ti2AlNb / high-strength aluminum alloy composite plate by utilizing the self-encasing structure.
[0073] The high-strength aluminum alloy sheet mentioned in step one is a 7-series high-strength aluminum alloy with grade 7075.
[0074] The area of the bottom platform mentioned in step one is smaller than that of the upper platform; the Ti2AlNb-based alloy plate mentioned in step two is matched with the bottom platform mentioned in step one; the back plate mentioned in step one first enters the rolling mill and the end is ground with a bevel.
[0075] The upper and lower platforms on one side of the back plate described in step one are arranged in a gradient from the outside to the inside. Specifically, they are prepared according to the following steps: First, a groove is machined on one side of the back plate to form the lower platform. Then, a step with a width of 10mm is machined along the upper edge of the lower platform to form the upper platform.
[0076] The Ti2AlNb-based alloy plate mentioned in step two is Ti-22Al-25Nb with a thickness of 1mm.
[0077] The sealing process described in step two involves applying an inorganic aluminosilicate high-temperature sealant. Specifically, the inorganic aluminosilicate is applied to the upper platform of the backplate, the Ti2AlNb-based alloy plate is placed in the lower platform of the backplate, the cover plate is placed on top, pressure is applied perpendicular to the upper surface of the cover plate, and the plate is left to stand for 12 hours. Then, the plate is kept at 80°C for 2 hours, and then at 150°C for 2 hours to complete the sealing.
[0078] In step two, a graphite sheet is placed between the Ti2AlNb-based alloy plate and the cover plate.
[0079] The heat treatment described in step three is carried out in the following steps: under vacuum and at a temperature of 200°C, the temperature is maintained for 60 minutes.
[0080] Comparative experiment: The difference between this implementation method and specific implementation method one is that the sealing process is omitted in step two. Everything else is the same as specific implementation method one.
[0081] Figure 5 This is a photograph of the Ti2AlNb / high-strength aluminum alloy composite plate prepared in Example 1. Figure 6 The image shows a physical photograph of the Ti2AlNb / high-strength aluminum alloy composite plate prepared in Example 2. It can be seen that, using a self-sealing composite plate, regardless of whether sealing treatment is applied, the Ti2AlNb-based alloy and the high-strength aluminum alloy are tightly bonded.
[0082] Figure 7The image shows a cross-sectional view of the Ti2AlNb / high-strength aluminum alloy composite plate prepared in Example 1. It can be seen that the two dissimilar alloys are tightly bonded, and the Ti2AlNb-based alloy exhibits uniform deformation. Therefore, this example demonstrates that it facilitates high-quality rolling of the Ti2AlNb / high-strength aluminum composite plate.
[0083] Tensile properties of Ti2AlNb / high-strength aluminum composite plates were tested using GB / T 228.1-2021 standard: Figure 8 The image shows the tensile stress-strain curve of the Ti2AlNb / high-strength aluminum alloy composite plate prepared in Example 1 at room temperature; the maximum stress is 630 MPa and the maximum strain is 11.2%. The curve contains two plateaus: the first plateau is when both metals yield together, and the second plateau is when only the high-strength aluminum alloy yields.
[0084] Figure 9 The image shows the thickness distribution of the Ti2AlNb / high-strength aluminum alloy composite plate prepared in Example 1. Twelve sampling points on the Ti2AlNb / high-strength aluminum alloy composite plate were measured using vernier calipers, and the data were recorded. It can be seen that the thickness ranges from 3.30 mm to 3.39 mm, and the thickness distribution is uniform.
Claims
1. A method for improving the rolling quality of Ti2AlNb / high-strength aluminum alloy composite plates using a self-coating structure, characterized in that... It is done in the following steps: I. Self-encasing structure and preparation: The back plate is made of high-strength aluminum alloy, and the cover plate is made of steel or high-strength aluminum alloy. The back plate and the cover plate form a self-enclosing structure. The back plate has an upper platform and a bottom platform arranged in a gradient from the outside to the inside on one side surface, with the bottom platform located at the bottom center of the upper platform; the cover plate matches the upper platform. II. Assembly: The bottom platform of the back plate and the side of the Ti2AlNb-based alloy plate that contacts the bottom platform are ground and cleaned. Then the Ti2AlNb-based alloy plate is placed in the bottom platform of the back plate and the cover plate is put on to obtain the part to be rolled. III. Composite Plate Rolling: The workpiece is held at 250℃~300℃ for 20min~30min, then held at 650℃~800℃ for 2min~5min. After holding, it is rolled at room temperature with a rolling speed of 0.5m / min~5m / min, a total reduction of 30%~70%, and 1~4 rolling passes. After rolling, it is heat treated to obtain the rolled composite plate. IV. Post-processing of composite panels: The cover plate on the rolled composite plate is removed, and then the excess back plate on all four sides is cut off. This completes the method of improving the rolling quality of Ti2AlNb / high-strength aluminum alloy composite plate by utilizing the self-encasing structure.
2. The method for improving the rolling quality of Ti2AlNb / high-strength aluminum alloy composite plates using a self-coating structure according to claim 1, characterized in that... The high-strength aluminum alloy mentioned in step one is a 2-series high-strength aluminum alloy or a 7-series high-strength aluminum alloy.
3. The method for improving the rolling quality of Ti2AlNb / high-strength aluminum alloy composite plates using a self-coating structure according to claim 1, characterized in that... The area of the bottom platform mentioned in step one is smaller than that of the upper platform; the Ti2AlNb-based alloy plate mentioned in step two is matched with the bottom platform mentioned in step one; the back plate mentioned in step one first enters the rolling mill and the end is ground with a bevel.
4. The method for improving the rolling quality of Ti2AlNb / high-strength aluminum alloy composite plates using a self-coating structure according to claim 1, characterized in that... The upper and lower platforms on one side of the back plate described in step one are arranged in a gradient from the outside to the inside. Specifically, they are prepared according to the following steps: First, a groove is machined on one side of the back plate to form the lower platform. Then, a step with a width of 10mm to 15mm is machined along the upper edge of the lower platform to form the upper platform.
5. A method for improving the rolling quality of Ti2AlNb / high-strength aluminum alloy composite plates using a self-coating structure according to claim 1, characterized in that... The Ti2AlNb-based alloy plate mentioned in step two is Ti-22Al-25Nb, Ti-23Al-17Nb, Ti-25Al-24Nb or Ti-22Al-27Nb.
6. A method for improving the rolling quality of Ti2AlNb / high-strength aluminum alloy composite plates using a self-coating structure according to claim 1, characterized in that... In step two, the cover plate is placed on and sealed; the sealing process involves applying high-temperature sealant or vacuum welding.
7. A method for improving the rolling quality of Ti2AlNb / high-strength aluminum alloy composite plates using a self-coating structure according to claim 6, characterized in that... In step two, a graphite sheet is placed between the Ti2AlNb-based alloy plate and the cover plate.
8. A method for improving the rolling quality of Ti2AlNb / high-strength aluminum alloy composite plates using a self-coating structure according to claim 1, characterized in that... The heat treatment described in step three is carried out in the following steps: under vacuum and at a temperature of 100℃~200℃, the temperature is maintained for 30min~60min.
9. A method for improving the rolling quality of Ti2AlNb / high-strength aluminum alloy composite plates using a self-coating structure according to claim 1, characterized in that... After heat preservation in step three, rolling is carried out within 30 seconds.