A metastable rolling method for preparing high-quality Ti2AlNb / high-strength aluminum double-layer composite plate by using high-temperature backing plate
By employing a high-temperature plate metastable rolling method, the forming temperature and deformation capacity of Ti2AlNb-based alloys and high-strength aluminum alloys were coordinated, solving the preparation problem of Ti2AlNb/high-strength aluminum double-layer composite plates and realizing the production of high-quality composite plates suitable for hypersonic aircraft skin and structural materials.
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
- 2026-07-03
Smart Images
Figure CN117862231B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a rolling method for Ti2AlNb / high-strength aluminum double-layer composite plates. Background Technology
[0002] With the rapid development of the military and aerospace industries, more and more aircraft are evolving towards ultra-high speed, high maneuverability, and high strike accuracy. The demands for increased Mach numbers, longer ranges, and low-cost mass production place stricter requirements on aircraft structural materials, which can no longer be met by the performance of single metals. Ti2AlNb-based alloys are a new type of lightweight, high-temperature resistant titanium-based alloy capable of long-term service at 650-750℃ and short-term service temperatures exceeding 800℃, meeting the strength and heat resistance requirements of aircraft during service. High-strength aluminum alloys are low-density and inexpensive materials, meeting the needs of weight reduction and low-cost manufacturing for aircraft. Ti2AlNb / high-strength aluminum composite plates can meet the requirements of short-term service across speed and temperature ranges for aircraft, showing great application potential. However, Ti2AlNb-based alloys and high-strength aluminum alloys differ significantly in forming temperature and deformation resistance, making coordinated rolling deformation and joining extremely difficult. Ti2AlNb-based alloys exhibit room temperature deformation resistance exceeding 1200 MPa and poor plasticity, with deformation resistance exceeding 500 MPa at 850℃. High-strength aluminum alloys can reach room temperature deformation resistance up to 600 MPa, but this resistance drops to less than 50 MPa above 500℃, and they are already in a molten state at 650℃. Using sheet metal torsion heating rolling or roll torsion heating rolling presents problems such as interface oxidation and difficulty in temperature control, making it difficult to achieve high-quality rolled joints. Summary of the Invention
[0003] This invention aims to solve the problem of difficulty in preparing Ti2AlNb / high-strength aluminum double-layer composite plates due to the incompatibility of rolling temperature and deformation resistance between existing Ti2AlNb-based alloys and high-strength aluminum alloys. It provides a metastable rolling method for preparing high-quality Ti2AlNb / high-strength aluminum double-layer composite plates using a high-temperature pad.
[0004] A metastable rolling method for preparing high-quality Ti2AlNb / high-strength aluminum double-layer composite plates using high-temperature pads, comprising the following steps:
[0005] I. Processing of high-strength aluminum alloy sheets and Ti2AlNb-based alloy sheets:
[0006] High-strength aluminum alloy sheet and Ti2AlNb-based alloy sheet are cut to obtain high-strength aluminum alloy billet and Ti2AlNb-based alloy billet, which are then ground, cleaned, stacked and sealed to obtain the part to be rolled.
[0007] II. Metastable rolling:
[0008] A hot pad is placed on one side of the Ti2AlNb-based alloy billet to be rolled. The hot pad and the workpiece are held at 250℃~300℃ for 20min~40min. Then, the workpiece is held at 650℃~800℃ for 2min~4min. After holding at 650℃~800℃, the workpiece is rolled in one pass within 30s at room temperature, rolling speed of 0.5m / min~5m / min and rolling amount of 30%~70% to obtain the rolled composite plate.
[0009] III. Post-rolling treatment:
[0010] The rolled composite plate is heat-treated, and then the heat pad is removed and trimmed, thus completing the metastable rolling method for preparing high-quality Ti2AlNb / high-strength aluminum double-layer composite plate using a high-temperature pad.
[0011] The beneficial effects of this invention are:
[0012] This invention achieves metastable rolling at room temperature using a heat-resistant pad, effectively coordinating the processing temperature and deformation capacity of the Ti2AlNb-based alloy and the high-strength aluminum alloy, successfully producing a high-quality Ti2AlNb / high-strength aluminum double-layer composite plate. The room-temperature rolling heat-resistant pad method ensures that the Ti2AlNb-based alloy does not directly contact the rolls, resulting in a slower temperature drop and better deformation capacity. The high-strength aluminum alloy, in direct contact with the rolls, experiences a faster temperature drop. Since the processing temperature is below the melting point, melting is avoided. Furthermore, the heat-resistant pad is made of steel, which prevents metallurgical diffusion between the steel and Ti2AlNb-based alloy, making it easy to remove during subsequent processing. Practical experience has shown that the heat-resistant pad exhibits almost no deformation during rolling and can be reused.
[0013] The Ti2AlNb / high-strength aluminum double-layer composite plate prepared by this invention can be used as a skin and structural material for hypersonic aircraft. The Ti2AlNb-based alloy side faces the short-term ultra-high temperature service environment, maintaining good heat resistance and high strength. The lightweight high-strength aluminum alloy side faces the interior of the aircraft and can be welded to other structural components, achieving maximum weight reduction. The Ti2AlNb / high-strength aluminum double-layer composite plate effectively combines excellent high-temperature service performance with lightweight and economical design.
[0014] Instruction manual illustrations
[0015] Figure 1 This is a schematic diagram of the design of placing the heat pad on one side of the Ti2AlNb-based alloy billet to be rolled in step two of the present invention.
[0016] Figure 2 The image shows the physical product of the Ti2AlNb / high-strength aluminum double-layer composite plate prepared in step three of Example 1.
[0017] Figure 3 The stress-strain diagram is obtained by tensile testing of the Ti2AlNb / high-strength aluminum double-layer composite plate prepared in step three of Example 1 at room temperature.
[0018] Figure 4 This is a port image of the Ti2AlNb / high-strength aluminum double-layer composite plate prepared in step three of Example 1, which was subjected to a tensile test at room temperature.
[0019] Figure 5 Three-point bending test of the Ti2AlNb / high-strength aluminum double-layer composite plate prepared in step three of Example 1;
[0020] Figure 6 This is a photograph of the Ti2AlNb / high-strength aluminum double-layer composite plate prepared in step three of Example 1, showing a three-point bending test.
[0021] Figure 7 The thickness distribution diagram is shown for the Ti2AlNb / high-strength aluminum double-layer composite plate prepared in step three of Example 1. Detailed Implementation
[0022] Specific implementation method one, combined with Figure 1 Detailed explanation: This embodiment describes a metastable rolling method for preparing high-quality Ti2AlNb / high-strength aluminum double-layer composite plates using a high-temperature pad. It is carried out according to the following steps:
[0023] I. Processing of high-strength aluminum alloy sheets and Ti2AlNb-based alloy sheets:
[0024] High-strength aluminum alloy sheet and Ti2AlNb-based alloy sheet are cut to obtain high-strength aluminum alloy billet and Ti2AlNb-based alloy billet, which are then ground, cleaned, stacked and sealed to obtain the part to be rolled.
[0025] II. Metastable rolling:
[0026] A hot pad is placed on one side of the Ti2AlNb-based alloy billet to be rolled. The hot pad and the workpiece are held at 250℃~300℃ for 20min~40min. Then, the workpiece is held at 650℃~800℃ for 2min~4min. After holding at 650℃~800℃, the workpiece is rolled in one pass within 30s at room temperature, rolling speed of 0.5m / min~5m / min and rolling amount of 30%~70% to obtain the rolled composite plate.
[0027] III. Post-rolling treatment:
[0028] The rolled composite plate is heat-treated, and then the heat pad is removed and trimmed, thus completing the metastable rolling method for preparing high-quality Ti2AlNb / high-strength aluminum double-layer composite plate using a high-temperature pad.
[0029] In step three of this specific implementation method, since the hot pad (steel) and the Ti2AlNb-based alloy are not metallurgically bonded, the hot pad is prone to falling off during the finishing process.
[0030] This specific embodiment utilizes a heat-absorbing plate to contact the Ti2AlNb-based alloy and employs a metastable rolling method to achieve synergistic deformation and effective bonding between the Ti2AlNb-based alloy and the high-strength aluminum alloy double-layer plate during rolling. This ensures a smooth surface and uniform thickness of the composite plate, thereby achieving high-quality preparation of the Ti2AlNb / high-strength aluminum double-layer composite plate.
[0031] The beneficial effects of this embodiment are:
[0032] This embodiment achieves metastable rolling at room temperature using a heat-resistant pad, effectively coordinating the processing temperature and deformation capacity of the Ti2AlNb-based alloy and the high-strength aluminum alloy, successfully producing a high-quality Ti2AlNb / high-strength aluminum double-layer composite plate. This embodiment employs room-temperature rolling with a heat-resistant pad, ensuring the Ti2AlNb-based alloy does not directly contact the rolls, resulting in a slower temperature drop and better deformation capacity. The high-strength aluminum alloy, in direct contact with the rolls, experiences a faster temperature drop. Since the processing temperature is below the melting point, melting is avoided. Furthermore, the heat-resistant pad is made of steel, which prevents metallurgical diffusion between the steel and Ti2AlNb-based alloy, making it easy to remove during subsequent processing. Practical experience shows that the heat-resistant pad exhibits almost no deformation during rolling and can be reused.
[0033] The Ti2AlNb / high-strength aluminum double-layer composite plate prepared in this embodiment can be used as a skin and structural material for hypersonic aircraft. The Ti2AlNb-based alloy side faces the short-term ultra-high temperature service environment, maintaining good heat resistance and high strength. The lightweight high-strength aluminum alloy side faces the interior of the aircraft and can be welded to other structural components, achieving maximum weight reduction. The Ti2AlNb / high-strength aluminum double-layer composite plate effectively combines good high-temperature service performance with lightweight and economical design.
[0034] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that it uses 2XXX series high-strength aluminum alloy or 7XXX series high-strength aluminum alloy. Everything else is the same as in Specific Implementation Method One.
[0035] Specific Implementation Method Three: This implementation method differs from Specific Implementation Method One or Two in that the Ti2AlNb-based alloy plate mentioned in step one is Ti-22Al-25Nb, Ti-23Al-17Nb, Ti-25Al-24Nb, or Ti-22Al-27Nb. Everything else is the same as in Specific Implementation Method One or Two.
[0036] Specific Implementation Method Four: This implementation method differs from Specific Implementation Methods One to Three in that the thickness ratio of the high-strength aluminum alloy billet to the Ti2AlNb-based alloy billet mentioned in step one is 1:(0.2~1), which is the same as Specific Implementation Methods One to Three.
[0037] Specific Implementation Method Five: This implementation method differs from Specific Implementation Methods One to Four in that: the area of the high-strength aluminum alloy billet mentioned in step one is larger than the area of the Ti2AlNb-based alloy billet; the area of the heat pad plate mentioned in step two is larger than the area of the Ti2AlNb-based alloy billet mentioned in step one. Everything else is the same as Specific Implementation Methods One to Four.
[0038] Specific Implementation Method Six: This implementation method differs from Specific Implementation Methods One to Five in that the sealing described in step one is specifically performed as follows: After stacking high-strength aluminum alloy billets and Ti2AlNb-based alloy billets, welding is carried out along the side surface gaps in a vacuum environment. Everything else is the same as in Specific Implementation Methods One to Five.
[0039] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Methods One to Six in that the heat pad mentioned in step two is made of 309 stainless steel, 309S stainless steel, or 310 stainless steel. Everything else is the same as in Specific Implementation Methods One to Six.
[0040] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Methods One to Seven in that the thickness of the heat pad in step two is 0.5 to 2 times the thickness of the Ti2AlNb-based alloy billet in step one. Everything else is the same as in Specific Implementation Methods One to Seven.
[0041] Specific Implementation Method Nine: This implementation method differs from Specific Implementation Methods One to Eight in that a layer of graphite sheet is placed between the hot pad and the workpiece to be rolled in step two. Everything else is the same as in Specific Implementation Methods One to Eight.
[0042] Specific Implementation Method Ten: This implementation method differs from Specific Implementation Methods One to Nine in that the heat treatment described in step three is specifically carried out under vacuum or atmospheric conditions and a temperature of 100℃~200℃, with a holding time of 30min~60min. Everything else is the same as in Specific Implementation Methods One to Nine.
[0043] The beneficial effects of the present invention are verified using the following embodiments:
[0044] Example 1:
[0045] A metastable rolling method for preparing high-quality Ti2AlNb / high-strength aluminum double-layer composite plates using high-temperature pads, comprising the following steps:
[0046] I. Processing of high-strength aluminum alloy sheets and Ti2AlNb-based alloy sheets:
[0047] High-strength aluminum alloy sheet and Ti2AlNb-based alloy sheet are cut to obtain high-strength aluminum alloy billet and Ti2AlNb-based alloy billet. Then the mating surfaces are ground, wiped with alcohol, stacked and sealed to obtain the parts to be rolled.
[0048] The high-strength aluminum alloy billet has a thickness of 3 mm; the Ti2AlNb-based alloy billet has a thickness of 1 mm.
[0049] II. Metastable rolling:
[0050] A hot pad is placed on one side of the Ti2AlNb-based alloy billet to be rolled. The hot pad and the workpiece are held at 300℃ for 20 minutes, and then held at 680℃ for 3 minutes. After holding at 680℃ for 30 seconds, the workpiece is rolled in one pass at room temperature, rolling speed of 2 m / min and rolling amount of 60% to obtain the rolled composite plate.
[0051] The thickness of the heat pad is 1mm;
[0052] III. Post-rolling treatment:
[0053] The rolled composite plate is heat-treated, then the heat pad is removed and trimmed to obtain a Ti2AlNb / high-strength aluminum double-layer composite plate. This completes the metastable rolling method for preparing high-quality Ti2AlNb / high-strength aluminum double-layer composite plates using a high-temperature pad.
[0054] The high-strength aluminum alloy sheet mentioned in step one is 7075 aluminum alloy.
[0055] The Ti2AlNb-based alloy plate mentioned in step one is Ti-22Al-25Nb.
[0056] The area of the high-strength aluminum alloy billet mentioned in step one is larger than the area of the Ti2AlNb-based alloy billet; the area of the pretreated heat pad mentioned in step two is larger than the area of the Ti2AlNb-based alloy billet mentioned in step one.
[0057] The sealing described in step one is carried out in the following steps: after stacking high-strength aluminum alloy billets and Ti2AlNb-based alloy billets, welding and sealing are performed along the side surface gaps in a vacuum environment to connect the two billets together and prevent oxygen from entering the contact surface of the two metals.
[0058] The heat pad mentioned in step two is made of 309 stainless steel.
[0059] The heat treatment described in step three is specifically performed under vacuum and at a temperature of 200°C for 60 minutes.
[0060] Figure 2 The image shows the actual Ti2AlNb / high-strength aluminum double-layer composite plate prepared in step three of Example 1. It can be seen that the Ti2AlNb layer is not cracked, and the deformation of the two metals is coordinated and uniform, proving that the heating pad method can successfully prepare the Ti2AlNb / high-strength aluminum double-layer composite plate.
[0061] Tensile properties of Ti2AlNb / high-strength aluminum double-layer composite plates were tested using GB / T 228.1-2021 standard; bending properties of Ti2AlNb / high-strength aluminum double-layer composite plates were tested using GB / T 232-2010 standard.
[0062] Figure 3 The stress-strain curve is obtained from a tensile test at room temperature of the Ti2AlNb / high-strength aluminum double-layer composite plate prepared in step three of Example 1. The curve is divided into two stages. In stage I, both metals are tensile deformed together, with a maximum stress of 770 MPa and a maximum strain of 7%. At the end of stage I, the stress drops sharply, at which point the Ti2AlNb-based alloy layer of the composite plate breaks first, while the high-strength aluminum alloy continues to undergo tensile deformation. In stage II, only the high-strength aluminum alloy undergoes tensile deformation, with a maximum stress of 262 MPa. The maximum strain at complete fracture of the composite plate is 10.2%. Therefore, the maximum stress before structural failure of the composite plate is 770 MPa, and the maximum strain at complete fracture is 10.2%.
[0063] Figure 4 This is a port image of the Ti2AlNb / high-strength aluminum double-layer composite plate prepared in step three of Example 1, subjected to a tensile test at room temperature. When the composite plate broke, the bonding surfaces of the two metals remained intact, demonstrating the high bonding strength at the composite plate's bonding surfaces.
[0064] Figure 5 The three-point bending test was performed on the Ti2AlNb / high-strength aluminum double-layer composite plate prepared in step three of Example 1. At room temperature, the maximum bending stress of the composite plate was 935 MPa and the maximum bending strain was 7%; at 200°C, the maximum bending stress of the composite plate was 785 MPa and the maximum bending strain was 4%.
[0065] Figure 6 The image shows a three-point bending test of the Ti2AlNb / high-strength aluminum double-layer composite plate prepared in step three of Example 1. As can be seen from the image, even when the composite plate undergoes significant bending deformation at room temperature and 200°C, the two metals remain connected and do not separate, demonstrating their high bonding strength.
[0066] Figure 7This is a thickness distribution diagram of the Ti2AlNb / high-strength aluminum double-layer composite plate prepared in step three of Example 1. Twelve sampling points on the Ti2AlNb / high-strength aluminum double-layer composite plate were measured using vernier calipers, and their thickness values were recorded. It can be seen that the thickness ranges from 1.76 mm to 1.9 mm, and the thickness distribution is uniform.
Claims
1. A metastable rolling method for preparing high-quality Ti2AlNb / high-strength aluminum double-layer composite plates using a high-temperature pad, characterized in that... It is done in the following steps: I. Processing of high-strength aluminum alloy sheets and Ti2AlNb-based alloy sheets: High-strength aluminum alloy sheet and Ti2AlNb-based alloy sheet are cut to obtain high-strength aluminum alloy billet and Ti2AlNb-based alloy billet, which are then ground, cleaned, stacked and sealed to obtain the part to be rolled. II. Metastable rolling: A hot pad is placed on one side of the Ti2AlNb-based alloy billet to be rolled. The hot pad and the workpiece are held at 250℃~300℃ for 20min~40min. Then, the workpiece is held at 650℃~800℃ for 2min~4min. After holding at 650℃~800℃, the workpiece is rolled in one pass within 30s at room temperature, rolling speed of 0.5m / min~5m / min and rolling amount of 30%~70% to obtain the rolled composite plate. III. Post-rolling treatment: The rolled composite plate is heat-treated, and then the heat pad is removed and trimmed, thus completing the metastable rolling method for preparing high-quality Ti2AlNb / high-strength aluminum double-layer composite plate using a high-temperature pad.
2. The metastable rolling method for preparing high-quality Ti2AlNb / high-strength aluminum double-layer composite plates using a high-temperature pad according to claim 1, characterized in that... The high-strength aluminum alloy sheet mentioned in step one is a 2XXX series high-strength aluminum alloy or a 7XXX series high-strength aluminum alloy.
3. The metastable rolling method for preparing high-quality Ti2AlNb / high-strength aluminum double-layer composite plates using a high-temperature pad according to claim 1, characterized in that... The Ti2AlNb-based alloy plate mentioned in step one is Ti-22Al-25Nb, Ti-23Al-17Nb, Ti-25Al-24Nb or Ti-22Al-27Nb.
4. The metastable rolling method for preparing high-quality Ti2AlNb / high-strength aluminum double-layer composite plates using a high-temperature pad according to claim 1, characterized in that... The thickness ratio of the high-strength aluminum alloy billet to the Ti2AlNb-based alloy billet mentioned in step one is 1:(0.2~1).
5. The metastable rolling method for preparing high-quality Ti2AlNb / high-strength aluminum double-layer composite plates using a high-temperature pad according to claim 1, characterized in that... The area of the high-strength aluminum alloy billet mentioned in step one is larger than the area of the Ti2AlNb-based alloy billet; the area of the heat pad mentioned in step two is larger than the area of the Ti2AlNb-based alloy billet mentioned in step one.
6. The method for preparing high-quality Ti2AlNb / high-strength aluminum double-layer composite plate by metastable rolling using a high-temperature pad according to claim 1, characterized in that... The sealing process described in step one is carried out in the following steps: after stacking high-strength aluminum alloy blanks and Ti2AlNb-based alloy blanks, welding and sealing are performed along the side surface gaps in a vacuum environment.
7. The metastable rolling method for preparing high-quality Ti2AlNb / high-strength aluminum double-layer composite plates using a high-temperature pad according to claim 1, characterized in that... The heat pad mentioned in step two is made of 309 stainless steel, 309S stainless steel, or 310 stainless steel.
8. The metastable rolling method for preparing high-quality Ti2AlNb / high-strength aluminum double-layer composite plates using a high-temperature pad according to claim 1, characterized in that... The thickness of the heat pad in step two is 0.5 to 2 times the thickness of the Ti2AlNb-based alloy billet in step one.
9. The metastable rolling method for preparing high-quality Ti2AlNb / high-strength aluminum double-layer composite plates using a high-temperature pad according to claim 1, characterized in that... In step two, a layer of graphite sheet is placed between the hot pad and the workpiece to be rolled.
10. The metastable rolling method for preparing high-quality Ti2AlNb / high-strength aluminum double-layer composite plates using a high-temperature pad according to claim 1, characterized in that... The heat treatment described in step three is specifically carried out under vacuum or atmospheric conditions and a temperature of 100℃~200℃, and held for 30min~60min.