Method for preparing copper-aluminum layered composite board by introducing laser into middle layer

Abstract

The invention discloses a method for preparing a copper-aluminum layered composite board by introducing laser into an intermediate layer, which comprises the following steps: introducing laser into the intermediate layer (Al-Cu-Mg-Si-Zr-Sc series alloy), so that on one hand, copper and aluminum to be compounded are in a heating state to be subjected to rolling compounding by utilizing the heat conduction effect of the heated intermediate layer; the rolling reduction rate and the rolling mill capacity requirement are obviously reduced; and on the other hand, the added middle layer has excellent obdurability, so that the cooperative deformation capacity between the to-be-compounded dissimilar materials can be improved, and the interface bonding performance of the composite material is improved. And a mode of'introducing laser into the middle layer and carrying out short-time online annealing treatment 'is adopted to replace'large down pressure and long-time diffusion annealing' adopted by a traditional copper-aluminum composite material, so that the processing and forming efficiency of the copper / aluminum composite material is remarkably improved, and the method has the characteristic of short process.

Description

Technical Field

[0001] The present invention relates to the technical field of copper-aluminum composite plates, and specifically relates to a method for preparing copper / aluminum laminated composite plates by introducing an intermediate layer using a laser. Background Art

[0002] Copper materials are widely used in many technical fields such as electronic components, the automotive industry, and construction engineering due to their outstanding electrical / thermal conductivity and excellent corrosion resistance. However, limited by its high material cost and limited natural resource reserves, there are obvious economic and sustainability challenges in the large-scale application of copper materials. Copper-aluminum composite plates are a type of laminated metal composite material that achieves metallurgical bonding between the copper layer and the aluminum layer through a specific composite process. They combine the electrical and thermal conductivity of copper and the low cost and lightweight advantages of aluminum. Therefore, copper-aluminum laminated composite plates show broad application prospects.

[0003] Currently, the cold rolling-diffusion annealing process is one of the main process methods for preparing copper-aluminum laminated composite plates. For example, the patent with the application number 202411602137.4 proposes a method for preparing copper-aluminum composite plates. First, the copper plate is subjected to roll pressing (several protrusions are obtained on the surface), alkali washing, annealing, and pickling. Then, the surface of the hot-rolled aluminum plate is mechanically polished. Then, the combination of copper and aluminum is achieved through single-pass large reduction cold rolling. Finally, the copper-aluminum composite plate is prepared by diffusion heat treatment. The patent with the application number 201810295821.0 proposes a method for preparing copper-aluminum composite strips, that is, a cold rolling process with a cumulative deformation of 80-95% is used to composite the copper plate and the aluminum strip after surface pretreatment. Subsequently, the cold-rolled composite copper-aluminum composite plate is subjected to high-temperature heat treatment under atmosphere protection to obtain the required finished product. It can be found from the above existing cold rolling-diffusion annealing treatment processes that they often require a large rolling deformation amount and a long-time high-temperature annealing treatment, resulting in high requirements for the rolling force of the rolling mill and low forming processing efficiency.

[0004] Therefore, this patent proposes a method of introducing an intermediate layer using a laser for copper-aluminum laminated composite plates, aiming to introduce an intermediate layer during the copper-aluminum rolling composite process based on the laser irradiation effect, and utilize the heat conduction effect and excellent co-deformation ability of the intermediate layer to achieve the efficient preparation and processing of multi-material copper-aluminum laminated composite plates. Summary of the Invention

[0005] In order to solve the problems that in the existing cold rolling-diffusion annealing treatment process for preparing copper-aluminum composite plates, a large rolling deformation amount is required, and long-time high-temperature annealing treatment is needed, resulting in high requirements for the rolling force of the rolling mill, large energy consumption, and low forming processing efficiency, the present invention provides a method for preparing a copper-aluminum laminated composite plate by introducing an intermediate layer with a laser. It realizes the efficient metallurgical composite of copper and aluminum through the synergistic effect of laser irradiation and the intermediate layer, significantly reduces the rolling reduction rate, reduces energy consumption, and improves the forming efficiency. It has the characteristics of excellent interfacial bonding performance of the composite plate, strong process compatibility, and adaptability to a variety of aluminum alloy materials.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions: The present invention provides a method for preparing a copper-aluminum laminated composite plate by introducing an intermediate layer with a laser, comprising the following steps: S1. Respectively convey a copper plate and an aluminum plate to a rolling mill; S2. Select an Al-Cu-Mg-Si-Zr-Sc series alloy as the intermediate layer, and use a cold spraying device to evenly cold spray the Al-Cu-Mg-Si-Zr-Sc series alloy powder onto the surface to be composite of the copper plate to obtain a pre-placed intermediate layer, and the thickness of the pre-placed intermediate layer is 0.15-0.4 mm; S3. Directly irradiate a laser beam onto the surface of the pre-placed intermediate layer. After laser irradiation, the Al-Cu-Mg-Si-Zr-Sc series alloy layer is in a semi-molten state. After the Al-Cu-Mg-Si-Zr-Sc series alloy layer is heated by laser irradiation, immediately bite into the rolls of the rolling mill, and transfer heat to the copper plate and the aluminum plate in contact with it through heat conduction, so that the copper plate and the aluminum plate are in a heated state, and use the pressing action of the rolls to realize the rolling composite of copper-intermediate layer-aluminum. The Al-Cu-Mg-Si-Zr-Sc series alloy layer remains in the copper-aluminum laminated composite plate in the form of an intermediate layer, and the rolling reduction rate of the rolling mill is 20-37%; S4. Anneal and flatten the copper-aluminum laminated composite plate after rolling composite by the rolling mill to obtain a finished product.

[0007] Adopt the above technical solutions: In the present invention, an Al-Cu-Mg-Si-Zr-Sc series alloy is used as the intermediate layer. The element ratio is dynamically adjusted according to the tensile strength of the aluminum layer (compared with the copper layer) to enhance the interfacial strength, toughness and bonding force, and improve the co-deformation ability. Subsequently, with the aid of laser irradiation, the Al-Cu-Mg-Si-Zr-Sc intermediate layer will be micro-melted, and the heat will be transferred to the copper / aluminum interface, softening the material and promoting plastic deformation. The Zr / Sc elements in the intermediate layer improve the strength and toughness, reducing the difference in deformation resistance between dissimilar metals. The rolling reduction rate only needs to be 20-37%, which is significantly lower than that of the traditional process. In addition, the bonding of the copper / aluminum interface only depends on mechanical interlocking and limited diffusion, and delamination is likely to occur. In the present invention, an Al-Cu-Mg-Si-Zr-Sc series alloy is used as the intermediate layer for bonding strengthening, and the element design of the intermediate layer optimizes the interfacial metallurgical bonding strength, greatly improving the bonding strength of the copper / aluminum interface. At the same time, the present invention does not require long-time diffusion annealing treatment after composite processing, improving the forming efficiency.

[0008] Further, in the step S2, when the tensile strength of the aluminum plate is less than or equal to that of the copper plate, the chemical composition of the Al-Cu-Mg-Si-Zr-Sc series alloy in the intermediate layer is: 2.8-3.5 wt% of Cu, 0.1-0.4 wt% of Mg, 0.7-1.1 wt% of Si, ≤0.1 wt% of Zr, ≤0.1 wt% of Sc, and the balance is Al.

[0009] Further, in the step S2, when the tensile strength of the aluminum plate is greater than that of the copper plate, the chemical composition of the Al-Cu-Mg-Si-Zr-Sc series alloy in the intermediate layer is: 3.3-4.7 wt% of Cu, 0.2-0.5 wt% of Mg, 0.8-1.3 wt% of Si, 0.2-0.5 wt% of Zr, 0.2-0.5 wt% of Sc, and the balance is Al.

[0010] The strength and toughness of the Al-Cu-Mg-Si-Zr-Sc series alloy selected in the present invention are between those of copper and aluminum, which is equivalent to adding an intermediate buffer layer during the copper-aluminum plate composite process, improving the co-deformation ability of copper and aluminum during the composite process.

[0011] In addition, in the present invention, the selection principle of the element content in the Al-Cu-Mg-Si-Zr-Sc series alloy is finally determined through a large number of experiments: when the strength of the aluminum plate is higher, the contents of Mg, Si, Zr, and Sc elements in the Al-Cu-Mg-Si-Zr-Sc series alloy in the intermediate layer are higher to improve the strength of the intermediate layer.

[0012] The copper layer to be composite is selected as the purple copper of grade T2. The aluminum alloys with tensile strength less than or equal to that of T2 copper are selected as 1060, 3003, etc., and the aluminum alloys with tensile strength greater than that of T2 copper are selected as 4004, 7050, etc.

[0013] Further, in the step S3, the wavelength of the laser beam emitted by the laser is 450 nm, and the laser power during rolling composite is 700 - 1300 W.

[0014] By controlling the laser power, the laser beam emitted by the laser irradiates the surface of the Al-Cu-Mg-Si-Zr-Sc alloy layer to form a micro-melting effect. The micro-melting state means that the outermost layer irradiated by the laser reaches above the melting point of the metal, and the layer thickness above the melting point is very thin (dozens of μm). The reason for achieving the micro-melting effect is that the micro-melting effect can well reduce the rolling force. However, if the layer above the melting point is thicker, pores are more likely to appear at the bonding interface.

[0015] Further, when performing rolling composite processing, a rectangular light spot with a uniform energy distribution is selected and irradiated on the surface of the pre-placed intermediate layer. The length direction of the rectangular light spot is the same as the width of the copper plate and the aluminum plate to be composite.

[0016] Further, the length of the rectangular light spot is 25 - 40 mm, and the width is 2 mm. The length of the rectangular light spot is the same as the width of the plate to be composite. Because usually during light spot shaping, the aspect ratio cannot be too large, so the length of the rectangular light spot is controlled within 25 - 40 mm, and the laser heating efficiency is good.

[0017] Further, in the step S3, the rolling composite speed of copper - intermediate layer - aluminum is 0.5 - 4 m / min.

[0018] Further, in the step S4, an online annealing treatment is performed on the composite copper-aluminum laminated composite plate by using a vacuum tunnel furnace arranged behind the rolling mill, and the annealing heating temperature is 310 - 370 °C. Since online annealing is adopted, the annealing time is consistent with the rolling composite speed.

[0019] Further, a cooling roller is arranged between the cold spraying device and the uncoiling device of the copper plate to ensure that the copper material at the uncoiling place is not affected by heat. A roller-type cooling device is arranged between the annealing treatment device and the leveling treatment device to ensure that the temperature of the copper-aluminum composite material before leveling treatment is lower than 50 °C.

[0020] Further, in the step S2, the particle size of the Al-Cu-Mg-Si-Zr-Sc alloy powder is 15 - 50 μm, the spraying distance during cold spraying is 20 - 30 mm, and the spraying angle is 90 degrees.

[0021] Specifically, according to the design requirements of the intermediate layer chemical composition, elemental powders with a purity ≥ 99.7% are used to obtain spraying alloy powders by mechanical mixing method. Nitrogen is selected as the powder feeding gas, and the spraying pressure and gas temperature are set to 3 - 5 MPa and 300 - 500 °C respectively. A pre-placed intermediate layer is obtained on the surface of the copper plate to be composite by using the cold spraying process.

[0022] Cold spraying is a process that accelerates metal or alloy powder particles to the substrate surface through a high-speed gas flow (supersonic or hypersonic), and uses the kinetic energy (rather than thermal energy) of the particles to achieve solid-state deposition. Through experimental verification, if the alloy powder particle size is too large: it has a large inertia and is difficult to accelerate, resulting in insufficient kinetic energy for impacting the substrate, unable to undergo plastic deformation, and difficult to bond with the substrate or the deposited layer. If the alloy powder particle size is too small: it is easily dispersed by the gas flow turbulence or deviated from the spraying path, and the deposition efficiency is significantly reduced. Therefore, in the present invention, the particle size of the Al-Cu-Mg-Si-Zr-Sc series alloy powder is finally selected to be 15 - 50 μm.

[0023] If the spraying distance is too far, the gas flow attenuation causes insufficient kinetic energy of the powder particles; if the spraying distance is too close, the high-speed gas flow damages the deposited coating. Therefore, in the present invention, the spraying distance during cold spraying is selected to be 20 - 30 mm, and the spraying angle is 90 degrees, that is, perpendicular impact, so that almost all of the kinetic energy of the particles is converted into normal variable energy, and the phenomenon of particle rebound does not occur.

[0024] Compared with the prior art, the present invention has the following beneficial effects: 1. In this invention patent, by introducing an intermediate layer with a laser, on the one hand, the heat conduction effect of the heated intermediate layer is used to promote the copper and aluminum to be compounded to be in a heated state for rolling compounding, significantly reducing the rolling reduction rate and the requirements for the rolling mill capacity; on the other hand, the added intermediate layer has excellent strength and toughness, which can improve the co-deformation ability between the dissimilar materials to be compounded, so as to improve the interfacial bonding performance of the composite material.

[0025] 2. This invention patent adopts the method of "introducing an intermediate layer with a laser + short-time on-line annealing treatment" to replace the "large reduction + long-time diffusion annealing" used in traditional copper-aluminum composite materials, significantly improving the processing and forming efficiency of copper / aluminum composite materials, and having the characteristics of short process flow. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The following will further describe the present invention in detail with reference to the drawings and specific embodiments.

[0027] Figure 1 It is a specific flow chart of the method for preparing a copper-aluminum laminated composite plate by introducing an intermediate layer with a laser in the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0029] Example 1 This example discloses a method for preparing a copper-aluminum laminated composite plate by introducing an intermediate layer with a laser, as Figure 1 shown, including the following steps: S1. Select oxygen-free copper with the grade of T2 for the copper plate and aluminum alloy 1060 with a tensile strength less than that of T2 copper for the aluminum plate. Unroll the copper plate coil and the aluminum plate coil respectively through the uncoiling device, and convey them to the rolling mill respectively. A cooling roller is arranged between the cold spraying device and the uncoiling device of the copper plate to ensure that the copper material at the uncoiling place is not affected by heat.

[0030] S2. Select an Al-Cu-Mg-Si-Zr-Sc series alloy as the intermediate layer, and its specific chemical composition is: 2.8wt% of Cu, 0.1wt% of Mg, 0.7wt% of Si, 0.02wt% of Zr, 0.02wt% of Sc, and the balance is Al.

[0031] S3. According to the design of the intermediate layer chemical composition, obtain the sprayed alloy powder by mechanical mixing of elemental powders with a purity ≥ 99.7%. Select nitrogen as the powder feeding gas. Set the spraying pressure and gas temperature of the cold spraying device to 3MPa and 300°C respectively. Obtain a preplaced intermediate layer on the surface to be compounded of the copper plate by the cold spraying process. During the cold spraying process, the spraying distance is 25mm, the spraying angle is 90 degrees, and the thickness of the obtained preplaced intermediate layer is 0.35mm.

[0032] S4. The wavelength of the laser beam emitted by the laser is 450nm, the laser power is 1050W, and a rectangular spot with a uniformly distributed spot energy irradiates the surface of the preplaced intermediate layer. The length direction of the rectangular spot is the same as the width of the copper plate and the aluminum plate to be compounded. The length of the rectangular spot is 40mm and the width is 2mm.

[0033] The Al-Cu-Mg-Si-Zr-Sc series alloy layer irradiated by the laser is in a semi-molten state. After the Al-Cu-Mg-Si-Zr-Sc series alloy layer is heated by the laser irradiation, it immediately bites into the rolls of the rolling mill, and transfers heat to the copper plate and the aluminum plate it contacts through heat conduction, prompting the copper plate and the aluminum plate to be in a heated state. By using the pressing action of the rolls, realize the rolling compounding of copper-intermediate layer-aluminum. The Al-Cu-Mg-Si-Zr-Sc series alloy layer remains in the copper-aluminum laminated composite plate in the form of an intermediate layer. The rolling reduction rate of the rolling mill is 37%, and the rolling compounding speed of copper-intermediate layer-aluminum is 2.7m / min.

[0034] S5. The online annealing treatment is carried out on the copper-aluminum laminated composite plate after lamination by using a vacuum tunnel furnace arranged behind the rolling mill, and the annealing heating temperature is 310 °C. Subsequently, by using a leveling device and a coiling mechanism, a finished copper-aluminum laminated composite plate with a waviness ≤ 3 mm / m is obtained. A roller press cooling device is arranged between the vacuum tunnel furnace and the leveling device to ensure that the temperature of the copper-aluminum composite material before leveling treatment is lower than 50 °C.

[0035] Through the shear test, the interfacial bonding strength of the above-mentioned T2-1060 copper-aluminum composite plate is 179 MPa.

[0036] Example 2 This example discloses a method for preparing a copper-aluminum laminated composite plate by introducing an intermediate layer with a laser, including the following steps: S1. The copper plate selects electrolytic copper with the grade of T2, and the aluminum plate selects aluminum alloy 3003 with a tensile strength less than that of T2 copper. The copper plate coil and the aluminum plate coil are respectively unrolled through an uncoiling device and then respectively conveyed to the rolling mill. A cooling roller is arranged between the cold spraying device and the uncoiling device of the copper plate to ensure that the copper material at the uncoiling place is not affected by heat.

[0037] S2. An Al-Cu-Mg-Si-Zr-Sc series alloy is selected as the intermediate layer, and the specific chemical composition is: 3.5 wt% of Cu, 0.4 wt% of Mg, 1.1 wt% of Si, 0.1 wt% of Zr, 0.1 wt% of Sc, and the balance is Al.

[0038] S3. According to the design of the intermediate layer chemical composition, the elemental powder with a purity ≥ 99.7% is obtained by mechanical mixing to obtain the spraying alloy powder. Nitrogen is selected as the powder feeding gas. The spraying pressure and gas temperature of the cold spraying device are respectively set to 3.7 MPa and 500 °C. A pre-placed intermediate layer is obtained on the surface to be laminated of the copper plate by using the cold spraying process. During the cold spraying process, the spraying distance is 20 mm, the spraying angle is 90 degrees, and the thickness of the pre-placed intermediate layer obtained by spraying is 0.15 mm.

[0039] S4. The wavelength of the laser beam emitted by the laser is 450 nm, the laser power is 700 W, and a rectangular spot with a uniformly distributed spot energy irradiates the surface of the pre-placed intermediate layer. The length direction of the rectangular spot is the same as the width of the copper plate and the aluminum plate to be laminated. The length of the rectangular spot is 25 mm and the width is 2 mm.

[0040] The laser-irradiated Al-Cu-Mg-Si-Zr-Sc alloy layer is in a semi-molten state. After being heated by laser irradiation, the Al-Cu-Mg-Si-Zr-Sc alloy layer immediately bites into the rolls of the rolling mill, and transfers heat to the copper plate and aluminum plate it contacts through heat conduction, causing the copper plate and aluminum plate to be in a heated state. With the pressing action of the rolls, the rolling composite of copper-intermediate layer-aluminum is realized. The Al-Cu-Mg-Si-Zr-Sc alloy layer is retained in the copper-aluminum laminated composite plate in the form of an intermediate layer. The rolling reduction rate of the rolling mill is 31%, and the rolling composite speed of copper-intermediate layer-aluminum is 4 m / min.

[0041] S5. The composite copper-aluminum laminated composite plate is subjected to online annealing treatment using a vacuum tunnel furnace arranged behind the rolling mill, and the annealing heating temperature is 330 °C. Subsequently, using a leveling device and a coiling mechanism, a finished copper-aluminum laminated composite plate with a waviness ≤ 3 mm / m is obtained. A roll-type cooling device is arranged between the vacuum tunnel furnace and the leveling device to ensure that the temperature of the copper-aluminum composite material before leveling treatment is lower than 50 °C.

[0042] Through the shear test, the interfacial bonding strength of the above-mentioned T2-3003 copper-aluminum composite plate is 141 MPa.

[0043] Example 3 This example discloses a method for preparing a copper-aluminum laminated composite plate by introducing an intermediate layer using a laser, including the following steps: S1. The copper plate selects electrolytic copper of grade T2, and the aluminum plate selects aluminum alloy 4004 with a tensile strength greater than that of T2 copper. The copper plate coil and the aluminum plate coil are respectively unrolled through an uncoiling device and conveyed to the rolling mill. A cooling roll is arranged between the cold spraying device and the uncoiling device of the copper plate to ensure that the copper material at the uncoiling place is not affected by heat.

[0044] S2. Select the Al-Cu-Mg-Si-Zr-Sc alloy system as the intermediate layer, and its specific chemical composition is: 3.3 wt% of Cu, 0.2 wt% of Mg, 0.8 wt% of Si, 0.2 wt% of Zr, 0.2 wt% of Sc, and the balance is Al.

[0045] S3. According to the design of the intermediate layer chemical composition, the elemental powder with a purity ≥ 99.7% is obtained by mechanical mixing to obtain the sprayed alloy powder. Nitrogen is selected as the powder feeding gas. The spraying pressure and gas temperature of the cold spraying device are set to 5 MPa and 400 °C respectively. A preformed intermediate layer is obtained on the surface of the copper plate to be composite by cold spraying process. During the cold spraying process, the spraying distance is 30 mm, the spraying angle is 90 degrees, and the thickness of the preformed intermediate layer obtained by spraying is 0.2 mm.

[0046] S4. The wavelength of the laser beam emitted by the laser is 450 nm, the laser power is 1300 W, and a rectangular spot with uniform energy distribution irradiates the surface of the pre-placed intermediate layer. The length direction of the rectangular spot is the same as the width of the copper plate and aluminum plate to be compounded. The length of the rectangular spot is 35 mm and the width is 2 mm.

[0047] The Al-Cu-Mg-Si-Zr-Sc alloy layer irradiated by the laser is in a semi-molten state. After being heated by the laser irradiation, the Al-Cu-Mg-Si-Zr-Sc alloy layer immediately bites into the rolls of the rolling mill, and transfers heat to the copper plate and aluminum plate it contacts through heat conduction, promoting the copper plate and aluminum plate to be in a heated state. With the pressing action of the rolls, the rolling compounding of copper-intermediate layer-aluminum is realized. The Al-Cu-Mg-Si-Zr-Sc alloy layer remains in the copper-aluminum laminated composite plate in the form of an intermediate layer. The rolling reduction rate of the rolling mill is 27%, and the rolling compounding speed of copper-intermediate layer-aluminum is 2 m / min.

[0048] S5. Use a vacuum tunnel furnace arranged behind the rolling mill to perform on-line annealing treatment on the composite copper-aluminum laminated composite plate, and the annealing heating temperature is 340 °C. Subsequently, use a leveling device and a coiling mechanism to obtain a finished copper-aluminum laminated composite plate with a waviness ≤ 3 mm / m. A roller-type cooling device is set between the vacuum tunnel furnace and the leveling device to ensure that the temperature of the copper-aluminum composite material before leveling treatment is lower than 50 °C.

[0049] Through the shear test, the interfacial bonding strength of the above-mentioned T2-4004 copper-aluminum composite plate is 153 MPa.

[0050] Example 4 This example discloses a method for preparing a copper-aluminum laminated composite plate by introducing an intermediate layer with a laser, including the following steps: S1. The copper plate selects oxygen-free copper of grade T2, and the aluminum plate selects aluminum alloy 7050 with a tensile strength greater than that of T2 copper. The copper plate coil and the aluminum plate coil are respectively unrolled through the uncoiling device and then respectively conveyed to the rolling mill. A cooling roll is set between the cold spraying device and the uncoiling device of the copper plate to ensure that the copper material at the uncoiling place is not affected by heat.

[0051] S2. Select the Al-Cu-Mg-Si-Zr-Sc alloy as the intermediate layer, and its specific chemical composition is: 4.7 wt% of Cu, 0.5 wt% of Mg, 1.3 wt% of Si, 0.5 wt% of Zr, 0.5 wt% of Sc, and the balance is Al.

[0052] S3. According to the design of the chemical composition of the intermediate layer, elemental powders with a purity of ≥99.7% are mechanically mixed to obtain sprayed alloy powders. Nitrogen is selected as the powder feeding gas. The spraying pressure and gas temperature of the cold spraying device are set at 4.7 MPa and 430 °C respectively. A preformed intermediate layer is obtained on the surface to be compounded of the copper plate by the cold spraying process. During the cold spraying process, the spraying distance is 27 mm, the spraying angle is 90 degrees, and the thickness of the preformed intermediate layer obtained by spraying is 0.17 mm.

[0053] S4. The wavelength of the laser beam emitted by the laser is 450 nm, the laser power is 1150 W, and a rectangular spot with a uniformly distributed spot energy irradiates the surface of the preformed intermediate layer. The length direction of the rectangular spot is the same as the width of the copper plate and aluminum plate to be compounded. The length of the rectangular spot is 29 mm and the width is 2 mm.

[0054] The Al-Cu-Mg-Si-Zr-Sc alloy layer irradiated by the laser is in a semi-molten state. After the Al-Cu-Mg-Si-Zr-Sc alloy layer is heated by the laser irradiation, it immediately bites into the rollers of the rolling mill, and transfers heat to the copper plate and aluminum plate it contacts through heat conduction, prompting the copper plate and aluminum plate to be in a heated state. With the pressing action of the rollers, the rolling compounding of copper-intermediate layer-aluminum is realized. The Al-Cu-Mg-Si-Zr-Sc alloy layer remains in the copper-aluminum laminated composite plate in the form of an intermediate layer. The rolling reduction rate of the rolling mill is 20%, and the rolling compounding speed of copper-intermediate layer-aluminum is 0.5 m / min.

[0055] S5. The compounded copper-aluminum laminated composite plate is subjected to online annealing treatment using a vacuum tunnel furnace arranged behind the rolling mill, and the annealing heating temperature is 370 °C. Subsequently, using a leveling device and a coiling mechanism, a finished copper-aluminum laminated composite plate with a waviness ≤3 mm / m is obtained. A roller-type cooling device is arranged between the vacuum tunnel furnace and the leveling device to ensure that the temperature of the copper-aluminum composite material before leveling treatment is lower than 50 °C.

[0056] Through the shear test, the interfacial bonding strength of the above-mentioned T2-7050 copper-aluminum composite plate is 154 MPa.

[0057] Comparative Example 1 Comparative Example 1 is a comparative test example of Example 1. It uses the cold rolling-diffusion annealing treatment process in the prior art (Example 3 in the patent with the publication number CN119368560 A) to obtain a copper-aluminum laminated composite plate. The interfacial bonding strength of the copper-aluminum composite plate after diffusion heat treatment is 102 MPa.

[0058] Although embodiments of the present invention have been shown and described, those of ordinary skill in the art will understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a copper-aluminum laminated plate by introducing an intermediate layer by laser, characterized in that: The steps include: S1, conveying the copper plate and the aluminum plate to the rolling mill respectively; S2. Al-Cu-Mg-Si-Zr-Sc alloy is selected as the intermediate layer, and Al-Cu-Mg-Si-Zr-Sc alloy powder is evenly cold-sprayed onto the surface of the copper plate to be composited by a cold spraying device to obtain a preset intermediate layer, wherein the thickness of the preset intermediate layer is 0.15-0.4 mm; S3, irradiate the laser beam directly on the surface of the preset intermediate layer, the Al-Cu-Mg-Si-Zr-Sc alloy layer irradiated by the laser is in a slightly melted state, and then the copper-intermediate layer-aluminum is rolled and composited under the rolling force of the rolling mill, and the Al-Cu-Mg-Si-Zr-Sc alloy layer is retained in the copper-aluminum layered composite plate in the form of an intermediate layer, and the rolling reduction rate of the rolling mill is 20-37%; S4, annealing and leveling the copper-aluminum layered composite plate after rolling and compounding by a rolling mill to obtain a finished product.

2. The method for preparing a copper-aluminum laminated plate by laser-introducing an intermediate layer according to claim 1, characterized in that: In step S2, when the tensile strength of the aluminum plate is less than or equal to that of the copper plate, the chemical composition of the intermediate layer Al-Cu-Mg-Si-Zr-Sc alloy is: 2.8-3.5wt% Cu, 0.1-0.4wt% Mg, 0.7-1.1wt% Si, ≤0.1wt% Zr, ≤0.1wt% Sc, and the remainder is Al.

3. The method for preparing a copper-aluminum laminated plate by laser-introducing an intermediate layer according to claim 1, characterized in that: In step S2, when the tensile strength of the aluminum plate is greater than that of the copper plate, the chemical composition of the intermediate layer Al-Cu-Mg-Si-Zr-Sc alloy is: 3.3-4.7wt% Cu, 0.2-0.5wt% Mg, 0.8-1.3wt% Si, 0.2-0.5wt% Zr, 0.2-0.5wt% Sc, and the remainder is Al.

4. The method for preparing a copper-aluminum laminated plate by laser-introducing an intermediate layer according to claim 1, characterized in that: In step S3, the wavelength of the laser beam emitted by the laser is 450nm, and the laser power during rolling and compounding is 700-1300W.

5. The method for preparing a copper-aluminum laminated plate by laser-introducing an intermediate layer according to claim 4, characterized in that: During rolling composite processing, a rectangular spot with uniform spot energy distribution is used and irradiated onto the surface of the preset intermediate layer. The length direction of the rectangular spot is the same as the width of the copper plate and aluminum plate to be composited.

6. The method for preparing a copper-aluminum laminated plate by laser-introducing an intermediate layer according to claim 5, characterized in that: The length of the rectangular spot is 25 to 40 mm and the width is 2 mm.

7. The method for preparing a copper-aluminum laminated plate by laser-introducing an intermediate layer according to claim 1, characterized in that: In the step S3, the speed of rolling and bonding the copper-intermediate layer-aluminum is 0.5-4 m / min.

8. The method for preparing a copper-aluminum laminated plate by laser-introducing an intermediate layer according to claim 1, characterized in that: In the step S4, the composite copper-aluminum layered composite plate is subjected to online annealing treatment by using a vacuum tunnel furnace arranged behind the rolling mill, and the annealing heating temperature is 310-370°C.

9. The method for preparing a copper-aluminum laminated plate by laser-introducing an intermediate layer according to claim 1, characterized in that: A cooling roller is arranged between the cold spraying device and the copper plate unwinding device, and a pressure roller type cooling device is arranged between the annealing treatment device and the leveling treatment device.

10. The method for preparing a copper-aluminum laminated plate by laser-introducing an intermediate layer according to claim 1, characterized in that: In step S2, the particle size of the Al-Cu-Mg-Si-Zr-Sc alloy powder is 15-50 μm, the spraying distance during cold spraying is 20-30 mm, and the spraying angle is 90 degrees.

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