High-performance aluminum alloy composite board for liquid cooling runner plate of power battery and preparation method of high-performance aluminum alloy composite board

Abstract

The invention discloses a high-performance aluminum alloy composite board for a liquid cooling runner plate of a power battery and a preparation method of the high-performance aluminum alloy composite board, the high-performance aluminum alloy composite board is formed by rolling and compounding a brazing layer, a core material layer and a corrosion-resistant layer, and the core material layer is prepared from the following raw materials in percentage by mass: 0.4-1.0% of Si, 0.2-0.7% of Fe, 0.2-1.1% of Cu, 1.2-1.8% of Mn, less than or equal to 0.05% of Zn, 0.05-0.3% of Ti, less than or equal to 0.05% of single content of other elements, less than or equal to 0.15% in total and the balance of Al. The preparation method of the high-performance aluminum alloy composite board comprises the steps of casting, homogenizing annealing, surface treatment, skin material hot rolling cogging, mechanical welding, heating before rolling, hot rolling compounding, cold rolling, finished product annealing, finishing and shearing. The high-performance aluminum alloy composite board provided by the invention is high in strength, high in ductility, excellent in forming performance and excellent in corrosion resistance after brazing.

Description

Technical Field

[0001] This invention belongs to the field of liquid cooling plates for power batteries, and specifically relates to a high-performance aluminum alloy composite plate for liquid cooling flow channel plates of power batteries and its preparation method. Background Technology

[0002] As the core power source of new energy vehicles, the energy density and charging / discharging power of power batteries are constantly breaking through their limits. This results in a large amount of heat generated during battery operation. If this heat is not effectively controlled in a timely manner, it will lead to uneven battery temperature distribution, accelerated capacity decay, and in severe cases, even thermal runaway, directly threatening vehicle safety. Therefore, the reliability of the power battery pack thermal management system has become one of the key factors restricting the high-quality development of the new energy vehicle industry.

[0003] As a core heat exchange component of the battery pack thermal management system, the liquid cooling plate achieves efficient heat dissipation and preheating of the power battery in low-temperature environments through the circulation of coolant (mainly a mixture of ethylene glycol and water) in its internal precision flow channels. This ensures that the battery always operates within the optimal temperature range of 15-35℃, providing crucial support for stable battery performance and lifespan. In the selection of materials for liquid cooling plates, aluminum alloys have become the mainstream choice in the industry due to their excellent thermal conductivity, good processability, and lightweight advantages. Among them, composite aluminum alloy sheets are widely used in the manufacture of liquid cooling flow channel plates because they can meet multiple performance requirements.

[0004] Currently, the most widely used liquid cooling channel plate material on the market is the 4045 / 3003MOD aluminum alloy composite plate. This composite plate adopts a double-layer composite structure design: the core material is made of 3003MOD aluminum alloy, which has moderate mechanical strength, excellent processing performance, and good thermal conductivity, meeting the structural stability requirements during the stamping process of the liquid cooling plate; the brazing layer is made of 4045 aluminum alloy, which contains a certain amount of Si element, has a low melting point (about 577℃), and has excellent brazing performance, ensuring reliable sealing of the flow channel during subsequent assembly. This double-layer composite structure exhibits good overall performance under normal operating conditions and has been widely adopted by major power battery manufacturers in the production of liquid cooling plates.

[0005] However, with the global expansion of the new energy vehicle market, the service environment of vehicles is becoming increasingly complex. In high-salt and high-humidity environments such as coastal areas and northern regions with heavy snowfall and frequent salting for de-icing, the corrosion failure of liquid cooling plates is becoming increasingly prominent, posing a significant hidden danger to the long-term safe operation of battery packs. Although the 4045 brazing layer and the 3003 MOD core material layer themselves possess certain corrosion resistance, in high-salt and high-humidity environments, the corrosion mode is mainly pitting corrosion, and the Cl in the environment... - SO4 2-Corrosive ions can diffuse into the battery pack through the sealed gaps, coming into direct contact with the surface of the liquid cooling plate. Over time, this forms micro-corrosion pits on the aluminum alloy surface. As service life increases, these pits deepen and expand, eventually leading to perforation and leakage of the liquid cooling plate. Once the coolant leaks, it not only causes the thermal management system to fail but can also trigger serious safety incidents such as battery short circuits and fires. More importantly, power battery packs are typically designed to have a lifespan exceeding 8 years or 160,000 kilometers. However, existing 4045 / 3003 MOD composite plates, due to insufficient corrosion resistance, struggle to maintain structural integrity and sealing reliability throughout their entire lifespan. Corrosion failure has become a core bottleneck restricting the long-term safety of battery packs.

[0006] To address the corrosion problem of liquid cooling plates, the industry has tried various auxiliary protective measures, such as attaching corrosion-inhibiting materials like polymer blue films or foam to the outside of the liquid cooling flow channel plates, or applying anti-corrosion coatings to the surface. However, these methods have significant drawbacks: on the one hand, they add extra production steps to the liquid cooling plates, reducing production cycle time and leading to a significant increase in manufacturing costs; on the other hand, the attached or coated protective layers are prone to peeling and aging during long-term use, making the protective effect unsustainable and failing to fundamentally solve the corrosion problem. Therefore, both automakers and battery manufacturers urgently hope that material manufacturers can innovate from the material system itself, improving the corrosion resistance of liquid cooling plates from the source by optimizing material design and composite processes.

[0007] 7072 aluminum alloy, a recognized high-performance anodic protection material, has a more negative electrode potential (approximately -0.85V) than 4045 aluminum alloy (approximately -0.75V) and 3003 MOD aluminum alloy (approximately -0.78V), exhibiting preferential corrosion characteristics in corrosive environments. It is often used as a cladding layer to protect the core material from corrosion. Theoretically, if 7072 aluminum alloy can be innovatively integrated with the traditional 4045 / 3003 MOD composite system to construct a multilayer aluminum alloy composite material that combines excellent brazing properties (4045 layer), reliable mechanical strength (3003 MOD core material layer), and long-term corrosion resistance (7072 cladding layer), it is expected to fundamentally solve the corrosion failure problem of liquid cooling plates.

[0008] However, in practical applications, the design and fabrication of multilayer aluminum alloy composites face numerous technical challenges: the compositional differences of different aluminum alloys lead to significant variations in their coefficients of thermal expansion, melting points, and processing properties, making problems such as weak interfacial bonding and interlayer delamination prone to occur during multilayer composite processes; simultaneously, it is necessary to ensure that the 7072 cladding layer fully utilizes the protective function of the sacrificial anode without affecting the brazing performance of the 4045 layer and the structural stability of the 3003 MOD core material layer, and there is a lack of mature experience in controlling its cladding thickness and composite process parameters. Currently, the industry has not yet developed a scalable multilayer aluminum alloy composite solution that combines brazingability, strength, and corrosion resistance, which cannot meet the stringent requirements of new energy vehicles for the long-term reliability of liquid cooling plates.

[0009] In summary, as the new energy vehicle industry continues to demand higher standards for the safety and lifespan of power batteries, the corrosion resistance of existing aluminum alloy composite materials used in liquid-cooled flow channels has become a key bottleneck restricting their development. Developing a novel high-performance multilayer aluminum alloy composite material that improves the corrosion resistance and long-term reliability of liquid-cooled plates from the material system itself, while also considering brazing performance, mechanical strength, and processing feasibility, has become an urgent technical challenge to be solved in the field of thermal management for new energy vehicles. This is of great significance for promoting the safe and sustainable development of the new energy vehicle industry. Summary of the Invention

[0010] The present invention aims to solve the problem of corrosion and leakage after the liquid cooling plate is made from existing flow channel liquid cooling plate materials, and provides a high-performance aluminum alloy composite plate for power battery liquid cooling flow channel plate and its preparation method.

[0011] The high-performance aluminum alloy composite plate for the liquid cooling flow channel plate of the power battery of the present invention has a three-layer composite structure, wherein the upper surface layer is a 4045 aluminum alloy layer, the core material layer is a 3003MOD aluminum alloy layer, and the lower surface layer is a 7072 aluminum alloy layer; the alloy elements of the 3003MOD aluminum alloy layer are as follows by mass percentage: Si: 0.4%~1.0%, Fe: 0.2%~0.7%, Cu: 0.2%~1.1%, Mn: 1.2%~1.8%, Zn≤0.05%, Ti: 0.05~0.3%, and the content of other elements is ≤0.05% for each individual element, totaling ≤0.15%, with the balance being Al.

[0012] The preparation method of a high-performance aluminum alloy composite plate for a power battery liquid cooling channel plate according to the present invention is completed according to the following steps:

[0013] I. Melting and Casting: The alloy elements of 4045 aluminum alloy layer, 3003 MOD aluminum alloy layer and 7072 aluminum alloy layer are proportioned according to their mass percentages, and 4045 aluminum alloy ingot, 3003 MOD aluminum alloy ingot and 7072 aluminum alloy ingot are melted and cast respectively; 4045 aluminum alloy ingot and 7072 aluminum alloy ingot are used as skin ingots.

[0014] II. Homogenization Annealing: The 3003MOD aluminum alloy ingot is subjected to homogenization annealing to obtain the core material ingot;

[0015] 3. Surface treatment: Mill the leather ingot and core ingot according to the specifications. The milling depth of the top and bottom surfaces is 5~20mm, and the milling depth of the small sides is 2~10mm. Cut off the head and tail of the ingot.

[0016] IV. Hot Rolling of Leather Materials: 4045 alloy ingots are placed in a heating furnace and preheated to 500~540℃, held for 2~6 hours, and then hot rolled to form a slab with a thickness of 49mm. The slab is then cut into 49×1600×4000mm sections to obtain 4045 hot-rolled billets. 7072 alloy ingots are placed in a heating furnace and preheated to 420~480℃, held for 2~6 hours, and then hot rolled to form a slab with a thickness of 35~65mm. The slab is then cut into (35~65)×1600×4000mm sections to obtain 7072 hot-rolled billets.

[0017] V. Mechanical Welding: The 7072 hot-rolled billet and the core material ingot are combined by drilling machinery, and then combined with the 4045 hot-rolled billet by drilling machinery to form a welded billet;

[0018] VI. Pre-rolling heating: The welded billet is heated at a temperature of 460~540℃ and held for 2~4 hours to obtain a preheated welded billet;

[0019] VII. Hot-rolled composite: The preheated welded billet is hot-rolled composite, with an initial rolling temperature of 420~480℃ and a final rolling temperature of ≥300℃. The final thickness after hot rolling is 6~10mm, to obtain a hot-rolled composite plate.

[0020] 8. Cold rolling: The hot-rolled composite plate is cold-rolled with a total cold rolling processing rate of 60-85% to obtain the cold-rolled composite plate;

[0021] 9. Finished product annealing: The cold-rolled composite sheet is annealed at a temperature of 320~440℃ for 1~3 hours, and then air-cooled to obtain the finished sheet.

[0022] 10. Gas-shielded brazing: Nitrogen-shielded brazing is performed on the finished sheet metal, and the corrosion performance of the composite board after brazing is tested.

[0023] Beneficial effects of this invention:

[0024] This invention simultaneously meets the stringent requirements of liquid cooling plates for stampability, brazingability, strength, and corrosion resistance on a single composite plate. The rational composition design results in high tensile strength in the finished plate, enhancing battery pack safety. The innovative 7072 sacrificial anode layer design provides active electrochemical protection for the core material layer and potential weld areas, significantly improving resistance to intergranular corrosion, exfoliation corrosion, and long-term coolant corrosion, thus extending the lifespan of the liquid cooling plate. The three-layer hot-rolled composite structure ensures a strong metallurgical bond between the three layers, with controllable process and high interfacial bonding strength. Attached Figure Description

[0025] Figure 1 The image shows the metallographic structure of the high-performance aluminum alloy composite plate prepared in Example 1 of this invention.

[0026] Figure 2 The image shows the polarized microstructure of the high-performance aluminum alloy composite plate prepared in Example 1 of this invention.

[0027] Figure 3 Comparison of the cross-sectional corrosion microstructure after salt spray corrosion in Example 1;

[0028] Figure 4 This is a comparison of the microstructure of the cross-section after salt spray corrosion in Comparative Example 1. Detailed Implementation

[0029] The technical solution of the present invention is not limited to the specific embodiments listed below, but also includes any combination of the specific embodiments.

[0030] Specific Implementation Method 1: In this implementation method, the high-performance aluminum alloy composite plate used for the liquid cooling flow channel plate of the power battery has a three-layer composite structure, wherein the upper surface layer is a 4045 aluminum alloy layer, the core material layer is a 3003MOD aluminum alloy layer, and the lower surface layer is a 7072 aluminum alloy layer; the alloy elements of the 3003MOD aluminum alloy layer are as follows by mass percentage: Si: 0.4%~1.0%, Fe: 0.2%~0.7%, Cu: 0.2%~1.1%, Mn: 1.2%~1.8%, Zn≤0.05%, Ti: 0.05~0.3%, and the content of other elements is ≤0.05% for each individual element, totaling ≤0.15%, with the balance being Al.

[0031] This embodiment achieves high-strength sheet material by precisely controlling the Mn and Cu content and optimizing work hardening behavior, recrystallization process, and texture development.

[0032] The high-performance aluminum alloy composite plate used for the liquid cooling channel plate of the power battery consists of an 8%~13% layer of 4045 aluminum alloy, a 3003 MOD core alloy layer, and an 8%~13% layer of 7072 aluminum alloy. The 4045 aluminum alloy is the brazing layer, and the 7072 aluminum alloy is the corrosion-resistant layer. Using this composite ratio, the amount of solder melted in the brazing layer meets brazing requirements without causing core material corrosion due to excessive solder. The composite ratio of the corrosion-resistant layer maximizes the corrosion resistance of the composite plate while ensuring its overall strength.

[0033] In this embodiment, the electrode potential of the 7072 aluminum alloy (-0.85V) is significantly lower than that of the traditional 4045 layer (-0.75V) and the 3003MOD core material layer (-0.78V). In high-salt, high-humidity environments, it preferentially undergoes electrochemical corrosion. By "sacrificing itself," it provides active protection for the core material layer and weld area, preventing corrosive ions from contacting the core structure and inhibiting pitting corrosion initiation from an electrochemical perspective. The upper 4045 aluminum alloy retains excellent brazability, ensuring reliable flow channel sealing. The 3003MOD core material optimizes its mechanical properties through precise control of Mn (1.2%~1.8%) and Cu (0.2%~1.1%) content. These three components form a synergistic match of "brazability-strength-corrosion resistance," avoiding the shortcomings of any single material performance.

[0034] In this embodiment, the 3003MOD core material limits Zn to ≤0.05% to reduce intergranular corrosion sensitivity, and Ti (0.05~0.3%) refines the grains and reduces the corrosion pit propagation rate.

[0035] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that the alloying elements of the 7072 aluminum alloy layer, by mass percentage, are: Si: 0.035%~0.040%, Fe: 0.08%~0.15%, Cu≤0.01%, Mn≤0.005%, Zn: 0.8%~1.3%, Ti≤0.02%, with the individual content of other elements ≤0.05%, totaling ≤0.15%, and the balance being Al. Other steps and parameters are the same as in Specific Implementation Method One.

[0036] In this embodiment, the impurity content of the 7072 layer is strictly controlled (Cu≤0.01%, Mn≤0.005%) to avoid impurities causing localized galvanic corrosion. At the same time, the Zn content (0.8%~1.3%) optimizes the sacrificial anode activity to ensure long-term protection.

[0037] In this embodiment, the layer serves as a sacrificial anode layer, providing active electrochemical protection for the core material layer.

[0038] Specific Implementation Method Three: This implementation method differs from Specific Implementation Method One in that the alloying elements of the 4045 aluminum alloy layer are as follows by mass percentage: Si: 9.5%~10.5%, Fe: 0.1~0.2%, Ti≤0.02%, and the content of other elements is ≤0.05% for each individual element, totaling ≤0.15%, with the balance being Al. Other steps and parameters are the same as in Specific Implementation Method One.

[0039] In this embodiment, the high Si content (9.5%~10.5%) of the 4045 layer ensures brazing fluidity, while controlling Fe ≤ 0.2% to avoid the formation of brittle intermetallic compounds that affect interfacial bonding, thereby indirectly improving corrosion resistance.

[0040] In this embodiment, this layer provides the welding materials required for gas-protected brazing.

[0041] Specific Implementation Method Four: This implementation method differs from Specific Implementation Method One in that the mechanical properties of the high-performance aluminum alloy composite plate used for the power battery liquid cooling channel plate meet the following requirements: yield strength 60~80MPa, tensile strength 140~160MPa, elongation ≥17%, and cupping value ≥8mm. Other steps and parameters are the same as in Specific Implementation Method One.

[0042] Specific Implementation Method Five: This implementation method differs from Specific Implementation Method One in that the corrosion performance of the high-performance aluminum alloy composite plate used for brazing the liquid cooling channel plate of the power battery meets the following requirements: corrosion depth < 100 μm and tensile strength > 140 MPa after 210 hours of copper accelerated salt spray corrosion. Other steps and parameters are the same as in Specific Implementation Method One.

[0043] Specific Implementation Method Six: The preparation method of a high-performance aluminum alloy composite plate for liquid cooling channel plate of a power battery in this implementation method is completed according to the following steps:

[0044] I. Melting and Casting: The alloy elements of 4045 aluminum alloy layer, 3003 MOD aluminum alloy layer and 7072 aluminum alloy layer are proportioned according to their mass percentages, and 4045 aluminum alloy ingot, 3003 MOD aluminum alloy ingot and 7072 aluminum alloy ingot are melted and cast respectively; 4045 aluminum alloy ingot and 7072 aluminum alloy ingot are used as skin ingots.

[0045] II. Homogenization Annealing: The 3003MOD aluminum alloy ingot is subjected to homogenization annealing to obtain the core material ingot;

[0046] 3. Surface treatment: Mill the leather ingot and core ingot according to the specifications. The milling depth of the top and bottom surfaces is 5~20mm, and the milling depth of the small sides is 2~10mm. Cut off the head and tail of the ingot.

[0047] IV. Hot Rolling of Leather Materials: 4045 alloy ingots are placed in a heating furnace and preheated to 500~540℃, held for 2~6 hours, and then hot rolled to form a slab with a thickness of 49mm. The slab is then cut into 49×1600×4000mm sections to obtain 4045 hot-rolled billets. 7072 alloy ingots are placed in a heating furnace and preheated to 420~480℃, held for 2~6 hours, and then hot rolled to form a slab with a thickness of 35~65mm. The slab is then cut into (35~65)×1600×4000mm sections to obtain 7072 hot-rolled billets.

[0048] V. Mechanical Welding: The 7072 hot-rolled billet and the core material ingot are combined by drilling machinery, and then combined with the 4045 hot-rolled billet by drilling machinery to form a welded billet;

[0049] VI. Pre-rolling heating: The welded billet is heated at a temperature of 460~540℃ and held for 2~4 hours to obtain a preheated welded billet;

[0050] VII. Hot-rolled composite: The preheated welded billet is hot-rolled composite, with an initial rolling temperature of 420~480℃ and a final rolling temperature of ≥300℃. The final thickness after hot rolling is 6~10mm, to obtain a hot-rolled composite plate.

[0051] 8. Cold rolling: The hot-rolled composite plate is cold-rolled with a total cold rolling processing rate of 60-85% to obtain the cold-rolled composite plate;

[0052] 9. Finished product annealing: The cold-rolled composite sheet is annealed at a temperature of 320~440℃ for 1~3 hours, and then air-cooled to obtain the finished sheet.

[0053] 10. Gas-shielded brazing: Nitrogen-shielded brazing is performed on the finished sheet metal, and the corrosion performance of the composite board after brazing is tested.

[0054] This implementation method employs a mechanical welding + hot rolling composite process. The pre-rolling heating of 460~540℃ and the initial rolling temperature of 420~480℃ match the hot processing window of the three-layer material, achieving a metallurgical-grade strong bond and preventing interlayer gaps from becoming channels for corrosive media. The total cold rolling processing rate of 60~85% and the finished product annealing of 320~440℃ work together to refine the microstructure of the composite plate, improve the interfacial bonding strength, and at the same time avoid the decrease in corrosion resistance caused by overheating. Nitrogen-protected brazing (605℃×5min) avoids the formation of oxide scale during the welding process and reduces weak points in the weld area.

[0055] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Method Six in that the dimensions of the 3003 MOD alloy ingot in step one are 420×1700×4150mm, the 4045 alloy ingot is 420×1620×4000mm, and the 7072 alloy ingot is 420×1620×4000mm. Other steps and parameters are the same as in Specific Implementation Method Six.

[0056] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Method Six in that the homogenization annealing treatment in step two is carried out at a homogenization temperature of 600~630℃ for 16~24 hours. Other steps and parameters are the same as in Specific Implementation Method Six.

[0057] Specific Implementation Method Nine: This implementation method differs from Specific Implementation Method Six in that: the coverage rate of the 4045 hot-rolled billet in step four is 10.0%; the specifications of the 7072 hot-rolled billet are (40~60)×1600×4000mm, and the coverage rate of the 7072 alloy layer is 8.0~12.0%. Other steps and parameters are the same as in Specific Implementation Method Six.

[0058] Specific Implementation Method Ten: This implementation method differs from Specific Implementation Method Six in that the heating temperature in step six is ​​480~520℃, and the holding time is 2~4 hours. Other steps and parameters are the same as in Specific Implementation Method Six.

[0059] Specific Implementation Method Eleven: This implementation method differs from Specific Implementation Method Six in that the initial rolling temperature in step seven is 460~480℃. Other steps and parameters are the same as in Specific Implementation Method Six.

[0060] Specific Implementation Method Twelve: This implementation method differs from Specific Implementation Method Six in that the thickness of the cold-rolled finished sheet in step eight is 0.5~2.0mm. Other steps and parameters are the same as in Specific Implementation Method Six.

[0061] Specific Implementation Method Thirteen: This implementation method differs from Specific Implementation Method Six in that the annealing temperature of the finished product in step nine is 360~420℃. Other steps and parameters are the same as in Specific Implementation Method Six.

[0062] Specific Implementation Method Fourteen: This implementation method differs from Specific Implementation Method Six in that the brazing process in step ten is performed at 605℃ for 5 minutes. Other steps and parameters are the same as in Specific Implementation Method Six.

[0063] The beneficial effects of the present invention are verified using the following embodiments:

[0064] Example 1: The composition and mass percentage of the core material 3003 MOD alloy are: Si: 0.7%, Fe: 0.45%, Cu: 0.75%, Mn: 1.5%, Zn: 0.02%, Ti: 0.12%, with individual content of other elements ≤0.05% and total ≤0.15%, with the balance being Al. The composition and mass percentage of the brazing layer 4045 alloy are: Si: 10.1%, Fe: 0.14%, Ti: 0.01%, with individual content of other elements ≤0.05% and total ≤0.15%, with the balance being Al. The composition and mass percentage of the corrosion-resistant layer 7072 alloy are: Si: 0.039%, Fe: 0.11%, Zn: 1.09%, Ti: 0.02%, with individual content of other elements ≤0.05% and total ≤0.15%, with the balance being Al.

[0065] (1) Melting and casting: 4045 aluminum alloy ingots, 3003 MOD aluminum alloy ingots and 7072 aluminum alloy ingots were melted and cast respectively to obtain 4045 and 7072 alloy ingots for leather material with a size of 420×1620×4000mm, and 3003 MOD alloy ingots for core material with a size of 420×1700×4150mm.

[0066] (2) Homogenization treatment: After the core alloy is cast, the ingot is heated to 610℃ and held for 18h to carry out homogenization annealing treatment of the alloy ingot in order to reduce and eliminate intragranular segregation.

[0067] (3) Surface treatment: Mill the brazing layer, corrosion-resistant layer and core material layer ingots according to the specifications. The milling depth of the top and bottom surfaces is 10mm, the milling depth of the small surfaces on both sides is 5mm, and the head and tail of the ingot are cut off.

[0068] (4) Hot rolling of the leather: The 4045 alloy ingot with brazing layer is pushed into the heating furnace and heated to 510°C. After holding for 2 hours, it is taken out of the furnace and hot rolled into a 50mm thick slab. Then the slab is cut into 50×1600×4000mm. The 7072 alloy ingot with corrosion resistant layer is pushed into the heating furnace and heated to 460°C. After holding for 2 hours, it is taken out of the furnace and hot rolled into a 52mm thick slab. Then the slab is cut into 52×1600×4000mm.

[0069] (5) Mechanical welding: The 7072 hot-rolled billet is mechanically combined with the 3003 MOD ingot and then mechanically combined with the 4045 hot-rolled billet to form a welded billet.

[0070] (6) Pre-rolling heating: The mechanically welded composite billet is heated to 480°C and kept at that temperature for 2 hours to obtain the composite hot plate billet.

[0071] (7) Hot rolling composite: The welded billet is hot rolled at an initial rolling temperature of 460℃ and a final rolling temperature of 320℃, with a final thickness of 6.5mm.

[0072] (8) Cold rolling: The hot-rolled composite plate is cold rolled. The thickness of the cold-rolled finished plate is 1.0 mm, and the total cold rolling processing rate is 85%.

[0073] (9) Finished product annealing: The composite cold-rolled coil is annealed at 380℃ for 2 hours.

[0074] (10) Finishing: The finished annealed coil is straightened and shaped on a bending straightening machine to obtain finished aluminum alloy composite sheet.

[0075] (11) Shearing: The finished aluminum alloy composite plate is sheared and shaped to obtain a high-performance aluminum alloy composite plate for power battery liquid cooling channel plate.

[0076] (12) Gas-protected brazing: The finished composite plate is placed into an industrial nitrogen-protected brazing furnace for simulated brazing. The simulated brazing temperature is 605℃ and the temperature is maintained for 5 minutes.

[0077] The longitudinal mechanical properties of the high-performance aluminum alloy composite plate for power battery liquid cooling channel plates prepared in this invention were tested according to GB / T 228.1-2021 "Metallic materials - Tensile testing - Part 1: Room temperature test method": yield strength 75.0 MPa, tensile strength 154.0 MPa, and elongation after fracture 25.7%. The cupping value of the composite plate was 10.4 mm, tested according to GB / T 4156-2007 "Metallic materials - Thin plates and strips - Eriksen cupping test". Corrosion tests were conducted on the brazed composite plate according to GB / T 10125-2021 "Artificial atmosphere corrosion test - Salt spray test", with the 7072 alloy layer as the corrosion exposed surface. After 210 hours of accelerated copper corrosion, the corrosion depth was 21.2 μm, and the tensile strength of the composite plate was 149.3 MPa.

[0078] Example 2: Core material 3003 MOD alloy composition and mass percentage: Si: 0.7%, Fe: 0.3%, Cu: 0.8%, Mn: 1.6%, Zn: 0.04%, Ti: 0.15%, with individual content of other elements ≤0.05%, total ≤0.15%, and balance Al. Brazing layer 4045 alloy composition and mass percentage: Si: 10.1%, Fe: 0.14%, Ti: 0.01%, with individual content of other elements ≤0.05%, total ≤0.15%, and balance Al. Corrosion-resistant layer 7072 alloy composition and mass percentage: Si: 0.039%, Fe: 0.11%, Zn: 1.09%, Ti: 0.02%, with individual content of other elements ≤0.05%, total ≤0.15%, and balance Al.

[0079] (1) Melting and casting: 4045 aluminum alloy ingots, 3003 MOD aluminum alloy ingots and 7072 aluminum alloy ingots were melted and cast respectively to obtain 4045 and 7072 alloy ingots for leather material with a size of 420×1620×4000mm, and 3003 MOD alloy ingots for core material with a size of 420×1700×4150mm.

[0080] (2) Homogenization treatment: After the core alloy is cast, the ingot is heated to 620°C and held for 14 hours to carry out homogenization annealing treatment of the alloy ingot in order to reduce and eliminate intragranular segregation.

[0081] (3) Surface treatment: Mill the brazing layer, corrosion-resistant layer and core material layer ingots according to the specifications. The milling depth of the top and bottom surfaces is 10mm, the milling depth of the small surfaces on both sides is 5mm, and the head and tail of the ingot are cut off.

[0082] (4) Hot rolling of the leather: The 4045 alloy ingot with brazing layer is pushed into the heating furnace and heated to 500°C. After holding for 3 hours, it is taken out of the furnace and hot rolled into a slab with a thickness of 49mm. Then the slab is cut into 49×1600×4000mm. The 7072 alloy ingot with corrosion resistant layer is pushed into the heating furnace and heated to 480°C. After holding for 1 hour, it is taken out of the furnace and hot rolled into a slab with a thickness of 39mm. Then the slab is cut into 39×1600×4000mm.

[0083] (5) Mechanical welding: The 7072 hot-rolled billet is mechanically combined with the 3003 MOD ingot and then mechanically combined with the 4045 hot-rolled billet to form a welded billet.

[0084] (6) Pre-rolling heating: The mechanically welded composite billet is heated to 500°C and kept at that temperature for 2 hours to obtain the composite hot plate billet.

[0085] (7) Hot rolling composite: The welded billet is hot rolled at an initial rolling temperature of 480℃ and a final rolling temperature of 330℃, with a final thickness of 6.5mm.

[0086] (8) Cold rolling: The hot-rolled composite plate is cold rolled. The thickness of the cold-rolled finished plate is 1.5 mm, and the total cold rolling processing rate is 77%.

[0087] (9) Finished product annealing: The composite cold-rolled coil is annealed at 400℃ and held for 2 hours.

[0088] (10) Finishing: The finished annealed coil is straightened and shaped on a bending straightening machine to obtain finished aluminum alloy composite plate.

[0089] (11) Shearing: The finished aluminum alloy composite plate is sheared and shaped to obtain a high-performance aluminum alloy composite plate for power battery liquid cooling channel plate.

[0090] (12) Gas-protected brazing: The finished composite plate is placed into an industrial nitrogen-protected brazing furnace for simulated brazing. The simulated brazing temperature is 605℃ and the temperature is maintained for 5 minutes.

[0091] The longitudinal mechanical properties of the high-performance aluminum alloy composite plate for power battery liquid cooling channel plates prepared in this invention were tested according to GB / T 228.1-2021 "Metallic materials - Tensile testing - Part 1: Room temperature test method": yield strength 77.0 MPa, tensile strength 160.0 MPa, and elongation after fracture 24.0%. The cupping value of the composite plate was 9.5 mm, tested according to GB / T 4156-2007 "Metallic materials - Thin plates and strips - Eriksen cupping test". Corrosion tests were conducted on the brazed composite plate according to GB / T 10125-2021 "Artificial atmosphere corrosion test - Salt spray test", with the 7072 alloy layer as the corrosion exposed surface. After 210 hours of accelerated copper corrosion, the corrosion depth was 24.1 μm, and the tensile strength of the composite plate was 155.2 MPa.

[0092] Example 3: Core material 3003 MOD alloy composition and mass percentage: Si: 0.5%, Fe: 0.2%, Cu: 0.7%, Mn: 1.5%, Zn: 0.03%, Ti: 0.14%, with individual content of other elements ≤0.05%, total ≤0.15%, and balance Al. Brazing layer 4045 alloy composition and mass percentage: Si: 10.1%, Fe: 0.14%, Ti: 0.01%, with individual content of other elements ≤0.05%, total ≤0.15%, and balance Al. Corrosion-resistant layer 7072 alloy composition and mass percentage: Si: 0.039%, Fe: 0.11%, Zn: 1.09%, Ti: 0.02%, with individual content of other elements ≤0.05%, total ≤0.15%, and balance Al.

[0093] (1) Melting and casting: 4045 aluminum alloy ingots, 3003 MOD aluminum alloy ingots and 7072 aluminum alloy ingots were melted and cast respectively to obtain 4045 and 7072 alloy ingots for leather material with a size of 420×1620×4000mm, and 3003 MOD alloy ingots for core material with a size of 420×1700×4150mm.

[0094] (2) Homogenization treatment: After the core alloy is cast, the ingot is heated to 610℃ and held for 18h to carry out homogenization annealing treatment of the alloy ingot in order to reduce and eliminate intragranular segregation.

[0095] (3) Surface treatment: Mill the brazing layer, corrosion-resistant layer and core material layer ingots according to the specifications. The milling depth of the top and bottom surfaces is 10mm, the milling depth of the small surfaces on both sides is 5mm, and the head and tail of the ingot are cut off.

[0096] (4) Hot rolling of the leather: The 4045 alloy ingot with brazing layer is pushed into the heating furnace and heated to 520°C. After holding for 2 hours, it is taken out of the furnace and hot rolled into a slab with a thickness of 49mm. Then the slab is cut into 49×1600×4000mm. The 7072 alloy ingot with corrosion resistant layer is pushed into the heating furnace and heated to 440°C. After holding for 3 hours, it is taken out of the furnace and hot rolled into a slab with a thickness of 39mm. Then the slab is cut into 39×1600×4000mm.

[0097] (5) Mechanical welding: The 7072 hot-rolled billet is mechanically combined with the 3003 MOD ingot and then mechanically combined with the 4045 hot-rolled billet to form a welded billet.

[0098] (6) Pre-rolling heating: The mechanically welded composite billet is heated to 480°C and kept at that temperature for 2 hours to obtain the composite hot plate billet.

[0099] (7) Hot rolling composite: The welded billet is hot rolled at an initial rolling temperature of 460℃ and a final rolling temperature of 320℃, with a final thickness of 6.5mm.

[0100] (8) Cold rolling: The hot-rolled composite plate is cold rolled. The thickness of the cold-rolled finished plate is 1.2 mm, and the total cold rolling processing rate is 82%.

[0101] (9) Finished product annealing: The composite cold-rolled coil is annealed at 380℃ for 2 hours.

[0102] (10) Finishing: The finished annealed coil is straightened and shaped on a bending straightening machine to obtain finished aluminum alloy composite plate.

[0103] (11) Shearing: The finished aluminum alloy composite plate is sheared and shaped to obtain a high-performance aluminum alloy composite plate for power battery liquid cooling channel plate.

[0104] (12) Gas-protected brazing: The finished composite plate is placed into an industrial nitrogen-protected brazing furnace for simulated brazing. The simulated brazing temperature is 605℃ and the temperature is maintained for 5 minutes.

[0105] The longitudinal mechanical properties of the high-performance aluminum alloy composite plate for power battery liquid cooling channel plates prepared in this invention were tested according to GB / T 228.1-2021 "Metallic materials - Tensile testing - Part 1: Room temperature test method": yield strength 72.0 MPa, tensile strength 150.0 MPa, and elongation after fracture 26.0%. The cupping value of the composite plate was 10.6 mm, tested according to GB / T 4156-2007 "Metallic materials - Thin plates and strips - Eriksen cupping test". Corrosion tests were conducted on the brazed composite plate according to GB / T 10125-2021 "Artificial atmosphere corrosion test - Salt spray test", with the 7072 alloy layer as the corrosion exposed surface. After 210 hours of accelerated copper corrosion, the average corrosion depth was 23.9 μm, and the tensile strength of the composite plate was 148.0 MPa.

[0106] Example 4: Core material 3003 MOD alloy composition and mass percentage: Si: 0.6%, Fe: 0.35%, Cu: 0.5%, Mn: 1.5%, Zn: 0.04%, Ti: 0.13%, with individual content of other elements ≤0.05%, total ≤0.15%, and balance Al. Brazing layer 4045 alloy composition and mass percentage: Si: 10.1%, Fe: 0.14%, Ti: 0.01%, with individual content of other elements ≤0.05%, total ≤0.15%, and balance Al. Corrosion-resistant layer 7072 alloy composition and mass percentage: Si: 0.039%, Fe: 0.11%, Zn: 1.09%, Ti: 0.02%, with individual content of other elements ≤0.05%, total ≤0.15%, and balance Al.

[0107] (1) Melting and casting: 4045 aluminum alloy ingots, 3003 MOD aluminum alloy ingots and 7072 aluminum alloy ingots were melted and cast respectively to obtain 4045 and 7072 alloy ingots for leather material with a size of 420×1620×4000mm, and 3003 MOD alloy ingots for core material with a size of 420×1700×4150mm.

[0108] (2) Homogenization treatment: After the core alloy is cast, the ingot is heated to 600℃ and held for 20h to carry out homogenization annealing treatment of the alloy ingot in order to reduce and eliminate intragranular segregation.

[0109] (3) Surface treatment: Mill the brazing layer, corrosion-resistant layer and core material layer ingots according to the specifications. The milling depth of the top and bottom surfaces is 10mm, the milling depth of the small surfaces on both sides is 5mm, and the head and tail of the ingot are cut off.

[0110] (4) Hot rolling of the leather: The 4045 alloy ingot with brazing layer is pushed into the heating furnace and heated to 500°C. After holding for 3 hours, it is taken out of the furnace and hot rolled into a slab with a thickness of 49mm. Then the slab is cut into 49×1600×4000mm. The 7072 alloy ingot with corrosion resistant layer is pushed into the heating furnace and heated to 460°C. After holding for 2 hours, it is taken out of the furnace and hot rolled into a slab with a thickness of 61mm. Then the slab is cut into 61×1600×4000mm.

[0111] (5) Mechanical welding: The 7072 hot-rolled billet is mechanically combined with the 3003 MOD ingot and then mechanically combined with the 4045 hot-rolled billet to form a welded billet.

[0112] (6) Pre-rolling heating: The mechanically welded composite billet is heated to 500°C and kept at that temperature for 1 hour to obtain the composite hot plate billet.

[0113] (7) Hot rolling composite: The welded billet is hot rolled at an initial rolling temperature of 480℃ and a final rolling temperature of 320℃, with a final thickness of 6.5mm.

[0114] (8) Cold rolling: The hot-rolled composite plate is cold rolled. The thickness of the cold-rolled finished plate is 1.0 mm, and the total cold rolling processing rate is 85%.

[0115] (9) Finished product annealing: The composite cold-rolled coil is annealed at 360℃ for 2 hours.

[0116] (10) Finishing: The finished annealed coil is straightened and shaped on a bending straightening machine to obtain finished aluminum alloy composite plate.

[0117] (11) Shearing: The finished aluminum alloy composite plate is sheared and shaped to obtain a high-performance aluminum alloy composite plate for power battery liquid cooling channel plate.

[0118] (12) Gas-protected brazing: The finished composite plate is placed into an industrial nitrogen-protected brazing furnace for simulated brazing. The simulated brazing temperature is 605℃ and the temperature is maintained for 5 minutes.

[0119] The longitudinal mechanical properties of the high-performance aluminum alloy composite plate for power battery liquid cooling channel plates prepared in this invention were tested according to GB / T 228.1-2021 "Metallic materials - Tensile testing - Part 1: Room temperature test method": yield strength 68.0 MPa, tensile strength 148.0 MPa, and elongation after fracture 26.2%. The cupping value of the composite plate was 11.1 mm, tested according to GB / T 4156-2007 "Metallic materials - Thin plates and strips - Eriksen cupping test". Corrosion tests were conducted on the brazed composite plate according to GB / T 10125-2021 "Artificial atmosphere corrosion test - Salt spray test", with the 7072 alloy layer as the corrosion exposed surface. After 210 hours of accelerated copper corrosion, the average corrosion depth was 24.5 μm, and the tensile strength of the composite plate was 146.8 MPa.

[0120] Comparative Example 1: The composition and mass percentage of the core material 3003 MOD alloy are: Si: 0.7%, Fe: 0.45%, Cu: 0.75%, Mn: 1.5%, Zn: 0.01%, Ti: 0.14%, with individual content of other elements ≤0.05% and total content ≤0.15%, with the balance being Al. The composition and mass percentage of the brazing layer 4045 alloy are: Si: 10.1%, Fe: 0.14%, Ti: 0.01%, with individual content of other elements ≤0.05% and total content ≤0.15%, with the balance being Al.

[0121] (1) Melting and casting: 4045 aluminum alloy ingots and 3003 MOD aluminum alloy ingots were melted and cast respectively to obtain 4045 alloy ingots for leather material with a size of 420×1620×4000mm and 3003 MOD alloy ingots for core material with a size of 420×1700×4150mm.

[0122] (2) Homogenization treatment: After the core alloy is cast, the ingot is heated to 610℃ and held for 18h to carry out homogenization annealing treatment of the alloy ingot in order to reduce and eliminate intragranular segregation.

[0123] (3) Surface treatment: Mill the brazing layer, corrosion-resistant layer and core material layer ingots according to the specifications. The milling depth of the top and bottom surfaces is 10mm, the milling depth of the small surfaces on both sides is 5mm, and the head and tail of the ingot are cut off.

[0124] (4) Hot rolling of the leather: The 4045 alloy ingot with brazing layer is pushed into the heating furnace and heated to 510°C. After holding for 2 hours, it is taken out of the furnace and hot rolled into a slab with a thickness of 49mm. Then the slab is cut into 49×1600×4000mm.

[0125] (5) Mechanical welding: The 4045 hot-rolled billet is mechanically combined with the 3003 MOD ingot to form a welded billet.

[0126] (6) Pre-rolling heating: The mechanically welded composite billet is heated to 480°C and kept at that temperature for 2 hours to obtain the composite hot plate billet.

[0127] (7) Hot rolling composite: The welded billet is hot rolled at an initial rolling temperature of 460℃ and a final rolling temperature of 315℃, with a final thickness of 4.0mm.

[0128] (8) Cold rolling: The hot-rolled composite plate is cold rolled. The thickness of the cold-rolled finished plate is 1.0 mm, and the total cold rolling processing rate is 75%.

[0129] (9) Finished product annealing: The composite cold-rolled coil is annealed at 400℃ and held for 2 hours.

[0130] (10) Finishing: The finished annealed coil is straightened and shaped on a bending straightening machine to obtain finished aluminum alloy composite plate.

[0131] (11) Shearing: The finished aluminum alloy composite plate is sheared and shaped to obtain a high-performance aluminum alloy composite plate for power battery liquid cooling channel plate.

[0132] (12) Gas-protected brazing: The finished composite plate is placed into an industrial nitrogen-protected brazing furnace for simulated brazing. The simulated brazing temperature is 605℃ and the temperature is maintained for 5 minutes.

[0133] The longitudinal mechanical properties of the high-performance aluminum alloy composite plate for liquid cooling channel plates of power batteries prepared in this invention were tested according to GB / T 228.1-2021 "Metallic materials - Tensile testing - Part 1: Test method at room temperature": yield strength 76.0 MPa, tensile strength 155.7 MPa, and elongation after fracture 25.8%. The cupping value of the composite plate was 10.3 mm, tested according to GB / T 4156-2007 "Metallic materials - Thin plates and strips - Eriksen cupping test". Corrosion tests were conducted on the brazed composite plate according to GB / T 10125-2021 "Artificial atmosphere corrosion test - Salt spray test", with the 3003 MOD alloy layer as the corrosion exposed surface. After 210 hours of accelerated copper corrosion, the average corrosion depth was 85.8 μm, and the tensile strength of the composite plate was 151.5 MPa.

[0134] Comparative Example 2: The composition and mass percentage of the core material 3003 MOD alloy are as follows: Si: 0.6%, Fe: 0.3%, Cu: 0.7%, Mn: 1.5%, Zn: 0.02%, Ti: 0.15%, with individual content of other elements ≤0.05% and total content ≤0.15%, with the balance being Al. The composition and mass percentage of the brazing layer 4045 alloy are as follows: Si: 10.1%, Fe: 0.14%, Ti: 0.01%, with individual content of other elements ≤0.05% and total content ≤0.15%, with the balance being Al.

[0135] (1) Melting and casting: 4045 aluminum alloy ingots and 3003 MOD aluminum alloy ingots were melted and cast respectively to obtain 4045 alloy ingots for leather material with a size of 420×1620×4000mm and 3003 MOD alloy ingots for core material with a size of 420×1700×4150mm.

[0136] (2) Homogenization treatment: After the core alloy is cast, the ingot is heated to 610℃ and held for 18h to carry out homogenization annealing treatment of the alloy ingot in order to reduce and eliminate intragranular segregation.

[0137] (3) Surface treatment: Mill the brazing layer, corrosion-resistant layer and core material layer ingots according to the specifications. The milling depth of the top and bottom surfaces is 10mm, the milling depth of the small surfaces on both sides is 5mm, and the head and tail of the ingot are cut off.

[0138] (4) Hot rolling of the leather: The 4045 alloy ingot with brazing layer is pushed into the heating furnace and heated to 500°C. After holding for 2 hours, it is taken out of the furnace and hot rolled into a slab with a thickness of 49mm. Then the slab is cut into 49×1600×4000mm.

[0139] (5) Mechanical welding: The 4045 hot-rolled billet is mechanically combined with the 3003 MOD ingot to form a welded billet.

[0140] (6) Pre-rolling heating: The mechanically welded composite billet is heated to 500°C and kept at that temperature for 2 hours to obtain the composite hot plate billet.

[0141] (7) Hot rolling composite: The welded billet is hot rolled at an initial rolling temperature of 480℃ and a final rolling temperature of 320℃, with a final thickness of 4.0mm.

[0142] (8) Cold rolling: The hot-rolled composite plate is cold rolled. The thickness of the cold-rolled finished plate is 1.0 mm, and the total cold rolling processing rate is 75%.

[0143] (9) Finished product annealing: The composite cold-rolled coil is annealed at 380℃ for 2 hours.

[0144] (10) Finishing: The finished annealed coil is straightened and shaped on a bending straightening machine to obtain finished aluminum alloy composite plate.

[0145] (11) Shearing: The finished aluminum alloy composite plate is sheared and shaped to obtain a high-performance aluminum alloy composite plate for power battery liquid cooling channel plate.

[0146] (12) Gas-protected brazing: The finished composite plate is placed into an industrial nitrogen-protected brazing furnace for simulated brazing. The simulated brazing temperature is 605℃ and the temperature is maintained for 5 minutes.

[0147] The longitudinal mechanical properties of the high-performance aluminum alloy composite plate for liquid cooling channel plates of power batteries prepared in this invention were tested according to GB / T 228.1-2021 "Metallic materials - Tensile testing - Part 1: Test method at room temperature": yield strength 68.0 MPa, tensile strength 154.1 MPa, and elongation after fracture 26.7%. The cupping value of the composite plate was 10.4 mm, tested according to GB / T 4156-2007 "Metallic materials - Thin plates and strips - Erikson cupping test". Corrosion tests were conducted on the brazed composite plate according to GB / T 10125-2021 "Artificial atmosphere corrosion test - Salt spray test", with the 3003 MOD alloy layer as the corrosion exposed surface. After 210 hours of accelerated copper corrosion, the average corrosion depth was 57.4 μm, and the tensile strength of the composite plate was 153.0 MPa.

Claims

1. A high-performance aluminum alloy composite sheet for a power battery liquid cooling runner plate, characterized in that The high-performance aluminum alloy composite plate for power battery liquid cooling flow channel plate is a three-layer composite structure, wherein the upper surface layer is a 4045 aluminum alloy layer, the core material layer is a 3003MOD aluminum alloy layer, and the lower surface layer is a 7072 aluminum alloy layer; the alloy elements of the 3003MOD aluminum alloy layer are as follows in terms of mass percentage: Si: 0.4%-1.0%, Fe: 0.2%-0.7%, Cu: 0.2%-1.1%, Mn: 1.2%-1.8%, Zn≤0.05%, Ti: 0.05-0.3%, the content of other elements is ≤0.05% individually, the total content of other elements is ≤0.15%, and the balance is Al.

2. The high-performance aluminum alloy composite sheet for a liquid cooling channel plate of a power battery according to claim 1, characterized in that The alloy elements of the 7072 aluminum alloy layer are as follows in terms of mass percentage: Si: 0.035%-0.040%, Fe: 0.08%-0.15%, Cu≤0.01%, Mn≤0.005%, Zn: 0.8%-1.3%, Ti≤0.02%, the content of other elements is ≤0.05% individually, the total content of other elements is ≤0.15%, and the balance is Al.

3. The high-performance aluminum alloy composite sheet for a liquid cooling channel plate of a power battery according to claim 1, characterized in that The alloy elements of the 4045 aluminum alloy layer are as follows in terms of mass percentage: Si: 9.5%-10.5%, Fe: 0.1-0.2%, Ti≤0.02%, the content of other elements is ≤0.05% individually, the total content of other elements is ≤0.15%, and the balance is Al.

4. The high-performance aluminum alloy composite sheet for a liquid cooling channel plate of a power battery according to claim 1, characterized in that The mechanical properties of the high-performance aluminum alloy composite plate for power battery liquid cooling flow channel plate meet the following requirements: yield strength: 60-80 MPa, tensile strength: 140-160 MPa, elongation: ≥17%, and cupping value: ≥8 mm.

5. The high-performance aluminum alloy composite sheet for a liquid cooling channel plate of a power battery according to claim 1, characterized in that The corrosion performance of the high-performance aluminum alloy composite plate for power battery liquid cooling flow channel plate after brazing meets the following requirements: corrosion depth: <100 μm after copper accelerated salt spray corrosion for 210 h, and tensile strength: >140 MPa.

6. The method for preparing a high-performance aluminum alloy composite plate for a liquid cooling channel plate of a power battery according to claim 1, characterized in that The preparation method of the high-performance aluminum alloy composite plate for power battery liquid cooling flow channel plate is completed by the following steps: I. Melting and casting: according to the mass percentage of the alloy elements of the 4045 aluminum alloy layer, the 3003MOD aluminum alloy layer and the 7072 aluminum alloy layer, the 4045 aluminum alloy ingot, the 3003MOD aluminum alloy ingot and the 7072 aluminum alloy ingot are respectively melted and cast; the 4045 aluminum alloy ingot and the 7072 aluminum alloy ingot are used as the skin material ingot; II. Homogenization annealing: the 3003MOD aluminum alloy ingot is subjected to homogenization annealing treatment to obtain the core material ingot; III. Surface treatment: the skin material ingot and the core material ingot are milled according to the specification requirements, the milling depth of the upper and lower surfaces is 5-20 mm, the milling depth of the two side surfaces is 2-10 mm, and the head and tail portions of the ingot are cut off; IV. Skin material hot rolling breakdown: the 4045 alloy ingot is preheated to 500-540 ℃ in a heating furnace, the holding time is 2-6 h, and then the ingot is taken out for hot rolling, the ingot is rolled into a plate blank with a thickness of 49 mm, and then the plate blank is cut into a 49×1600×4000 mm plate to obtain a 4045 hot rolled blank; the 7072 alloy ingot is preheated to 420-480 ℃ in a heating furnace, the holding time is 2-6 h, and then the ingot is taken out for hot rolling, the ingot is rolled into a plate blank with a thickness of 35-65 mm, and then the plate blank is cut into a (35-65)×1600×4000 mm plate to obtain a 7072 hot rolled blank; V. Mechanical welding: the 7072 hot-rolled blank and the core ingot are mechanically compounded by drilling, and then the 4045 hot-rolled blank is mechanically compounded by drilling to form a welding blank; VI. Pre-rolling heating: the welding blank is heated at a temperature of 460-540℃ for 2-4h to obtain a preheated welding blank; VII. Hot rolling: the preheated welding blank is hot-rolled at an initial rolling temperature of 420-480℃ and a final rolling temperature of ≥300℃ to obtain a hot-rolled composite plate with a thickness of 6-10mm; VIII. Cold rolling: the hot-rolled composite plate is cold-rolled at a total processing rate of 60-85% to obtain a cold-rolled composite plate; IX. Product annealing: the cold-rolled composite plate is annealed at a temperature of 320-440℃ for 1-3h, and then air-cooled to obtain a finished plate; X. Gas shielded brazing: the finished plate is nitrogen shielded brazed, and the corrosion performance of the brazed composite plate is detected.

7. The method of claim 6, wherein the method further comprises the steps of: providing a high-performance aluminum alloy composite sheet; and subjecting the high-performance aluminum alloy composite sheet to a heat treatment process. In step one, the 3003MOD alloy ingot has a size of 420×1700×4150mm, the 4045 alloy ingot has a size of 420×1620×4000mm, and the 7072 alloy ingot has a size of 420×1620×4000mm.

8. The method of claim 6, wherein the method further comprises: forming the high-performance aluminum alloy composite plate for a liquid cooling channel plate of a power battery by using a high-performance aluminum alloy plate and a high-performance aluminum alloy plate as the first plate and the second plate, respectively. In step two, the soaking temperature of the homogenization annealing treatment is 600-630℃, and the holding time is 16-24h.

9. The method of claim 6, wherein the method further comprises: forming the high-performance aluminum alloy composite plate for the liquid cooling channel plate of the power battery by using a high-performance aluminum alloy plate and a high-performance aluminum alloy plate as the base plate and the cover plate, respectively, and then performing a diffusion bonding process on the high-performance aluminum alloy plate and the high-performance aluminum alloy plate. In step four, the cladding rate of the 4045 hot-rolled blank is 10.0%, the 7072 hot-rolled blank has a size of (40-60)×1600×4000mm, and the cladding rate of the 7072 alloy layer is 8.0-12.0%.

10. The method of claim 6, wherein the method further comprises: forming the high-performance aluminum alloy composite plate for a liquid cooling channel plate of a power battery by using a high-performance aluminum alloy plate and a high-performance aluminum alloy plate as the first plate and the second plate, respectively. In step ten, the brazing process is performed at 605℃ for 5min.

Images