A method for preparing copper-aluminum layered composite plate by introducing an intermediate layer using laser

Abstract

This invention discloses a method for preparing copper-aluminum layered composite plates using a laser-introduced intermediate layer (an Al-Cu-Mg-Si-Zr-Sc alloy). By laser-introducing the intermediate layer (an Al-Cu-Mg-Si-Zr-Sc alloy), the heat conduction effect of the heated intermediate layer facilitates rolling and bonding of the copper and aluminum to be composited while they are heated, significantly reducing rolling reduction and mill capacity requirements. Furthermore, the added intermediate layer exhibits excellent toughness, enhancing the synergistic deformation capability of the composite materials to improve the composite's interfacial bonding properties. The method employs a "laser-introduced intermediate layer followed by a short online annealing process," replacing the "high downforce combined with long diffusion annealing" process used in traditional copper / aluminum composites. This significantly improves the processing efficiency of the copper / aluminum composites and streamlines the process.

Description

Technical Field

[0001] The invention relates to the technical field of copper / aluminum composite plates, and in particular to a method for preparing a copper / aluminum layered composite plate by introducing an intermediate layer with laser. Background Art

[0002] Copper, with its outstanding electrical and thermal conductivity and excellent corrosion resistance, is widely used in a variety of technical fields, including electronic components, the automotive industry, and construction engineering. However, due to its high material cost and limited natural resource reserves, the large-scale application of copper faces obvious economic and sustainability challenges. Copper-aluminum composite panels are a type of layered metal composite material that achieves metallurgical bonding of copper and aluminum layers through a specific composite process. They combine the electrical and thermal conductivity of copper with the low cost and lightweight advantages of aluminum. Therefore, copper-aluminum layered composite panels show broad application prospects.

[0003] Currently, cold rolling-diffusion annealing is one of the main processes for producing copper-aluminum laminates. For example, patent application number 202411602137.4 proposes a method for producing copper-aluminum laminates. The method involves first rolling the copper sheet (to obtain a few surface reliefs), then alkali washing, annealing, and pickling. The hot-rolled aluminum sheet is then mechanically polished. The copper and aluminum are then bonded via a single-pass high-reduction cold rolling process. Finally, a diffusion heat treatment is performed to produce the copper-aluminum laminate. Patent application number 201810295821.0 proposes a method for producing copper-aluminum laminate strips. This involves laminating the surface-pretreated copper sheet and aluminum strip using a cold rolling process with a cumulative deformation of 80-95%. The cold-rolled laminate is then subjected to a high-temperature heat treatment under a protective atmosphere to obtain the desired finished product. The existing cold rolling-diffusion annealing process often requires large rolling deformation and long, high-temperature annealing times, resulting in high mill force requirements and low forming efficiency.

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

[0005] In order to solve the problem that the existing cold rolling-diffusion annealing process requires large rolling deformation and long-term high-temperature annealing when preparing copper-aluminum composite plates, resulting in high rolling force requirements, high energy consumption and low forming processing efficiency of the rolling mill, the present invention provides a method for preparing copper-aluminum layered composite plates by introducing an intermediate layer using laser. The method realizes 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 forming efficiency. The method has the characteristics of excellent interface 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:

[0007] The present invention provides a method for preparing a copper-aluminum layered composite plate by introducing an intermediate layer using laser, comprising the following steps:

[0008] S1, transporting the copper plate and aluminum plate to the rolling mill respectively;

[0009] 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 using a cold spraying device to obtain a preset intermediate layer, wherein the thickness of the preset intermediate layer is 0.15 to 0.4 mm;

[0010] S3. Directly irradiate the surface of the pre-deposited intermediate layer with a laser beam. The Al-Cu-Mg-Si-Zr-Sc alloy layer irradiated by the laser is in a slightly molten state. After being heated by the laser irradiation, the Al-Cu-Mg-Si-Zr-Sc alloy layer immediately bites into the rollers of the rolling mill and transfers heat to the copper and aluminum plates it contacts through heat conduction, so that the copper and aluminum plates are in a heated state. The copper-intermediate layer-aluminum rolling composite is achieved by utilizing the pressing action of the rollers. 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. The rolling reduction rate of the rolling mill is 20-37%.

[0011] S4, annealing and leveling the copper-aluminum laminated plate after rolling and laminating in a rolling mill to obtain a finished product.

[0012] Using the above technical solution:

[0013] The present invention uses an Al-Cu-Mg-Si-Zr-Sc alloy as an intermediate layer. The element ratio is dynamically adjusted according to the tensile strength of the aluminum layer (compared with the copper layer), enhancing the interface toughness and bonding strength, and improving the cooperative deformation ability. Subsequent laser irradiation will cause the Al-Cu-Mg-Si-Zr-Sc intermediate layer to melt slightly, and heat is transferred to the copper / aluminum interface, softening the material and promoting plastic deformation. The Zr / Sc elements in the intermediate layer enhance toughness and reduce the difference in deformation resistance between dissimilar metals. The rolling reduction rate only needs to be 20-37%, which is significantly lower than the rolling reduction rate of traditional processes. In addition, the copper / aluminum interface bonding relies solely on mechanical bite and limited diffusion, which is prone to delamination. The present invention uses an Al-Cu-Mg-Si-Zr-Sc alloy as an intermediate layer for bonding and strengthening. The intermediate layer element design optimizes the interface metallurgical bonding strength, significantly improving the bonding strength of the copper / aluminum interface. At the same time, the present invention does not require a long-term diffusion annealing heat treatment after composite processing, thereby improving forming efficiency.

[0014] Furthermore, 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.

[0015] Furthermore, 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: 3.3-4.7 wt% Cu, 0.2-0.5 wt% Mg, 0.8-1.3 wt% Si, 0.2-0.5 wt% Zr, 0.2-0.5 wt% Sc, and the remainder is Al.

[0016] The strength and toughness of the Al-Cu-Mg-Si-Zr-Sc alloy selected in the present invention is between that of copper and aluminum, which is equivalent to adding an intermediate buffer layer during the composite process of copper and aluminum plates, thereby improving the collaborative deformation ability of copper and aluminum during the composite process.

[0017] In addition, the present invention finally determined the principle of selecting the element content in the Al-Cu-Mg-Si-Zr-Sc alloy through a large number of experiments: when the strength of the aluminum plate is higher, the content of Mg, Si, Zr and Sc elements in the middle layer Al-Cu-Mg-Si-Zr-Sc alloy is higher to improve the strength of the middle layer.

[0018] The copper layer to be composited is made of red copper with the grade of T2, the aluminum alloy with a tensile strength less than or equal to T2 copper is made of 1060, 3003, etc., and the aluminum alloy with a tensile strength greater than T2 copper is made of 4004, 7050, etc.

[0019] Furthermore, in step S3, the wavelength of the laser beam emitted by the laser is 450 nm, and the laser power during rolling and compounding is 700-1300 W.

[0020] By controlling the laser power, the laser beam emitted by the laser is irradiated on 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 surface layer irradiated by the laser reaches above the melting point of the metal, and the thickness of the layer above the melting point is very thin (tens of μm). The reason for achieving the micro-melting effect is that the micro-melting effect can greatly reduce the rolling force. However, if the layer above the melting point is thicker, the bonding interface is more likely to have pores.

[0021] Furthermore, during the rolling composite process, a rectangular light spot with uniform light spot energy distribution is selected and irradiated onto the surface of the preset intermediate layer. The length direction of the rectangular light spot is the same as the width of the copper plate and aluminum plate to be composited.

[0022] Furthermore, the length of the rectangular spot is 25 to 40 mm and the width is 2 mm. The length of the rectangular spot is consistent with the width of the plate to be composited. Because the aspect ratio cannot be too large when shaping the spot, the length of the rectangular spot is controlled within 25 to 40 mm, which improves the laser heating efficiency.

[0023] Furthermore, in step S3, the speed of rolling and bonding the copper-intermediate layer-aluminum is 0.5-4 m / min.

[0024] Furthermore, in step S4, the composite copper-aluminum laminate is subjected to online annealing in a vacuum tunnel furnace arranged behind the rolling mill, with the annealing heating temperature being 310-370° C. Since online annealing is adopted, the annealing time is consistent with the rolling composite speed.

[0025] Furthermore, a cooling roller is installed between the cold spraying device and the copper plate unwinding device to ensure that the copper material at the unwinding location is not affected by heat. A pressure roller cooling device is installed between the annealing device and the leveling device to ensure that the temperature of the copper-aluminum composite material is below 50°C before the leveling process.

[0026] Furthermore, in step S2, the particle size of the Al-Cu-Mg-Si-Zr-Sc alloy powder is 15 to 50 μm, the spraying distance during the cold spraying process is 20 to 30 mm, and the spraying angle is 90 degrees.

[0027] Specifically, according to the design requirements of the chemical composition of the intermediate layer, the single-element powder with a purity of ≥99.7% is mechanically mixed to obtain the spray alloy powder, nitrogen is selected as the powder feeding gas, the spraying pressure and gas temperature are set to 3-5MPa and 300-500℃ respectively, and the preset intermediate layer is obtained by cold spraying process on the surface to be composited of the copper plate.

[0028] Cold spraying is a process that uses a high-speed airflow (supersonic or transonic) to accelerate metal or alloy powder particles onto the substrate surface, utilizing the particles' kinetic energy (rather than thermal energy) to achieve solid-state deposition. Experimental verification has shown that excessively large alloy powder particle size results in high inertia, making acceleration difficult. This results in insufficient kinetic energy upon impact with the substrate, preventing plastic deformation and hindering bonding with the substrate or existing deposited layers. Excessively small alloy powder particle size is easily dispersed by airflow turbulence or deflected from the spray path, significantly reducing deposition efficiency. Therefore, the Al-Cu-Mg-Si-Zr-Sc alloy powder selected in this invention has a particle size of 15 to 50 μm.

[0029] If the spraying distance is too far, the airflow attenuates, resulting in insufficient kinetic energy for the powder particles. If the spraying distance is too close, the high-speed airflow destroys the deposited coating. Therefore, in the present invention, the cold spraying process is performed at a spray distance of 20-30 mm and a spray angle of 90 degrees, i.e., vertical impact, which converts almost all of the particle kinetic energy into normal energy and prevents the particles from rebounding.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] 1. The patent of this invention introduces an intermediate layer through laser. On the one hand, the heat conduction effect of the heated intermediate layer is used to promote the copper and aluminum to be composited to be in a heated state and undergo rolling composite, which significantly reduces the rolling reduction rate and rolling mill capacity requirements; on the other hand, the added intermediate layer has excellent strength and toughness, which can enhance the cooperative deformation ability between the dissimilar materials to be composited, thereby improving the interface bonding performance of the composite material.

[0032] 2. The patent of this invention adopts the method of "laser introduction of intermediate layer + short-time online annealing treatment", which replaces the "large pressure 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 has the characteristics of short process. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] Figure 1 This is a specific flowchart of the method for preparing a copper-aluminum layered composite plate by introducing an intermediate layer using laser according to the present invention. DETAILED DESCRIPTION

[0035] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0036] Example 1

[0037] This embodiment discloses a method for preparing a copper-aluminum laminated plate by introducing an intermediate layer using laser. Figure 1 As shown, the following steps are included:

[0038] S1. Copper plates are made of T2 copper, and aluminum plates are made of 1060 aluminum alloy, which has a tensile strength lower than that of T2 copper. Copper and aluminum coils are unwound separately through uncoiling devices and transported to the rolling mill. A cooling roller is installed between the cold spray device and the copper plate uncoiling device to protect the copper at the uncoiling site from heat.

[0039] S2. Al-Cu-Mg-Si-Zr-Sc alloy is selected as the intermediate layer, and the specific chemical composition is: 2.8wt% Cu, 0.1wt% Mg, 0.7wt% Si, 0.02wt% Zr, 0.02wt% Sc, and the balance is Al.

[0040] S3. According to the chemical composition design of the intermediate layer, a single substance powder with a purity of ≥99.7% is mechanically mixed to obtain a spraying alloy powder. Nitrogen is selected as the powder feeding gas. The spraying pressure and gas temperature of the cold spraying device are set to 3 MPa and 300°C, respectively. A cold spraying process is used to obtain a preset intermediate layer on the surface to be composited of the copper plate. During the cold spraying process, the spraying distance is 25 mm, the spraying angle is 90 degrees, and the thickness of the preset intermediate layer obtained by spraying is 0.35 mm.

[0041] S4. The wavelength of the laser beam emitted by the laser is 450nm, the laser power is 1050W, and a rectangular spot with uniformly distributed spot energy is irradiated on 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. The length of the rectangular spot is 40mm and the width is 2mm.

[0042] The Al-Cu-Mg-Si-Zr-Sc alloy layer irradiated by laser is in a slightly molten state. After being heated by laser irradiation, the Al-Cu-Mg-Si-Zr-Sc alloy layer immediately bites into the roller of the rolling mill and transfers heat to the copper and aluminum plates it contacts through heat conduction, causing the copper and aluminum plates to be in a heated state. The copper-intermediate layer-aluminum rolling composite is achieved by utilizing the pressure of the roller. 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. The rolling reduction rate of the rolling mill is 37%, and the speed of the copper-intermediate layer-aluminum rolling composite is 2.7m / min.

[0043] S5. The copper-aluminum composite sheet undergoes in-line annealing in a vacuum tunnel furnace located behind the rolling mill at a temperature of 310°C. Subsequently, a leveling device and a winding mechanism are used to obtain a finished copper-aluminum composite sheet with a waviness of ≤3 mm / m. A roller-type cooling device is installed between the vacuum tunnel furnace and the leveling device to ensure that the temperature of the copper-aluminum composite material is below 50°C before leveling.

[0044] Through shear tests, the interface bonding strength of the T2-1060 copper-aluminum composite panel is 179 MPa.

[0045] Example 2

[0046] This embodiment discloses a method for preparing a copper-aluminum layered composite plate by introducing an intermediate layer using laser, comprising the following steps:

[0047] S1. Copper plates are made of T2 copper, and aluminum plates are made of 3003 aluminum alloy, which has a tensile strength lower than that of T2 copper. Copper and aluminum coils are unwound separately through uncoiling devices and transported to the rolling mill. A cooling roller is installed between the cold spraying device and the copper plate uncoiling device to protect the copper at the uncoiling site from heat.

[0048] S2. Al-Cu-Mg-Si-Zr-Sc alloy is selected as the intermediate layer, and the specific chemical composition is: 3.5wt% Cu, 0.4wt% Mg, 1.1wt% Si, 0.1wt% Zr, 0.1wt% Sc, and the balance is Al.

[0049] S3. According to the chemical composition design of the intermediate layer, a single substance powder with a purity of ≥99.7% is mechanically mixed to obtain a spray alloy powder. Nitrogen is selected as the powder feeding gas. The spraying pressure and gas temperature of the cold spraying device are set to 3.7 MPa and 500°C, respectively. A cold spraying process is used to obtain a preset intermediate layer on the surface to be composited of the copper plate. During the cold spraying process, the spraying distance is 20 mm, the spraying angle is 90 degrees, and the thickness of the preset intermediate layer obtained by spraying is 0.15 mm.

[0050] S4. The wavelength of the laser beam emitted by the laser is 450nm, the laser power is 700W, and a rectangular spot with uniformly distributed spot energy is irradiated on 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. The length of the rectangular spot is 25mm and the width is 2mm.

[0051] The Al-Cu-Mg-Si-Zr-Sc alloy layer irradiated by laser is in a slightly molten state. After being heated by laser irradiation, the Al-Cu-Mg-Si-Zr-Sc alloy layer immediately bites into the rolling mill rollers and transfers heat to the copper and aluminum plates it contacts through heat conduction, causing the copper and aluminum plates to be in a heated state. The copper-intermediate layer-aluminum rolling composite is achieved by utilizing the pressing action of the rolling rollers. 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. The rolling reduction rate of the rolling mill is 31%, and the copper-intermediate layer-aluminum rolling composite speed is 4m / min.

[0052] S5. The copper-aluminum composite sheet undergoes in-line annealing in a vacuum tunnel furnace located behind the rolling mill at a temperature of 330°C. Subsequently, a leveling device and a winding mechanism are used to obtain a finished copper-aluminum composite sheet with a waviness of ≤3 mm / m. A roller-type cooling device is installed between the vacuum tunnel furnace and the leveling device to ensure that the temperature of the copper-aluminum composite material is below 50°C before leveling.

[0053] Through shear tests, the interface bonding strength of the T2-3003 copper-aluminum composite panel is 141 MPa.

[0054] Example 3

[0055] This embodiment discloses a method for preparing a copper-aluminum layered composite plate by introducing an intermediate layer using laser, comprising the following steps:

[0056] S1. Copper plates are made of T2 copper, and aluminum plates are made of 4004 aluminum alloy, which has a tensile strength greater than that of T2 copper. Copper and aluminum coils are unwound separately through uncoiling devices and transported to the rolling mill. A cooling roller is installed between the cold spray device and the copper plate uncoiling device to protect the copper at the uncoiling site from heat.

[0057] S2. Al-Cu-Mg-Si-Zr-Sc alloy is selected as the intermediate layer, and the specific chemical composition is: 3.3wt% Cu, 0.2wt% Mg, 0.8wt% Si, 0.2wt% Zr, 0.2wt% Sc, and the balance is Al.

[0058] S3. According to the chemical composition design of the intermediate layer, the single-element powder with a purity of ≥99.7% is mechanically mixed 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 set to 5 MPa and 400°C respectively, and the preset intermediate layer is obtained by cold spraying on the surface to be composited of the copper plate. During the cold spraying process, the spraying distance is 30 mm, the spraying angle is 90 degrees, and the thickness of the preset intermediate layer obtained by spraying is 0.2 mm.

[0059] S4. The wavelength of the laser beam emitted by the laser is 450nm, the laser power is 1300W, and a rectangular spot with uniformly distributed spot energy is irradiated on 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. The length of the rectangular spot is 35mm and the width is 2mm.

[0060] The Al-Cu-Mg-Si-Zr-Sc alloy layer irradiated by laser is in a slightly molten state. After being heated by laser irradiation, the Al-Cu-Mg-Si-Zr-Sc alloy layer immediately bites into the rolling mill rollers and transfers heat to the copper and aluminum plates it contacts through heat conduction, causing the copper and aluminum plates to be in a heated state. The copper-intermediate layer-aluminum rolling composite is achieved by utilizing the pressure of the rolling rollers. 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. The rolling reduction rate of the rolling mill is 27%, and the copper-intermediate layer-aluminum rolling composite speed is 2m / min.

[0061] S5. The copper-aluminum composite sheet undergoes in-line annealing at 340°C in a vacuum tunnel furnace located behind the rolling mill. Subsequently, a leveling device and a winding mechanism are used to obtain a finished copper-aluminum composite sheet with a waviness of ≤3 mm / m. A roller-type cooling device is installed between the vacuum tunnel furnace and the leveling device to ensure that the temperature of the copper-aluminum composite material is below 50°C before leveling.

[0062] Through shear tests, the interface bonding strength of the T2-4004 copper-aluminum composite plate is 153 MPa.

[0063] Example 4

[0064] This embodiment discloses a method for preparing a copper-aluminum layered composite plate by introducing an intermediate layer using laser, comprising the following steps:

[0065] S1. Copper plates are made of T2 copper, and aluminum plates are made of 7050 aluminum alloy, which has a tensile strength greater than that of T2 copper. Copper and aluminum coils are unwound separately through uncoiling devices and transported to the rolling mill. A cooling roller is installed between the cold spray device and the copper plate uncoiling device to protect the copper at the uncoiling site from heat.

[0066] S2. Al-Cu-Mg-Si-Zr-Sc alloy is selected as the intermediate layer, and the specific chemical composition is: 4.7wt% Cu, 0.5wt% Mg, 1.3wt% Si, 0.5wt% Zr, 0.5wt% Sc, and the balance is Al.

[0067] S3. According to the chemical composition design of the intermediate layer, the single-element powder with a purity of ≥99.7% is mechanically mixed to obtain the spray alloy powder. Nitrogen is selected as the powder feeding gas. The spraying pressure and gas temperature of the cold spray device are set to 4.7 MPa and 430°C respectively. The preset intermediate layer is obtained by cold spraying on the surface to be composited of the copper plate. During the cold spraying process, the spraying distance is 27 mm, the spraying angle is 90 degrees, and the thickness of the preset intermediate layer obtained by spraying is 0.17 mm.

[0068] S4. The wavelength of the laser beam emitted by the laser is 450nm, the laser power is 1150W, and a rectangular spot with uniformly distributed spot energy is irradiated on 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. The length of the rectangular spot is 29mm and the width is 2mm.

[0069] The Al-Cu-Mg-Si-Zr-Sc alloy layer irradiated by laser is in a slightly molten state. After being heated by laser irradiation, the Al-Cu-Mg-Si-Zr-Sc alloy layer immediately bites into the rolling mill rollers and transfers heat to the copper and aluminum plates it contacts through heat conduction, causing the copper and aluminum plates to be in a heated state. The copper-intermediate layer-aluminum rolling composite is achieved by utilizing the pressing action of the rolling rollers. 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. The rolling reduction rate of the rolling mill is 20%, and the copper-intermediate layer-aluminum rolling composite speed is 0.5m / min.

[0070] S5. The copper-aluminum composite sheet undergoes in-line annealing in a vacuum tunnel furnace located behind the rolling mill at a temperature of 370°C. Subsequently, a leveling device and a winding mechanism are used to obtain a finished copper-aluminum composite sheet with a waviness of ≤3 mm / m. A roller-type cooling device is installed between the vacuum tunnel furnace and the leveling device to ensure that the temperature of the copper-aluminum composite material is below 50°C before leveling.

[0071] Through shear tests, the interface bonding strength of the T2-7050 copper-aluminum composite panel is 154 MPa.

[0072] Comparative Example 1

[0073] Comparative Example 1 is a comparative test example of Example 1. This example utilizes the existing cold rolling and diffusion annealing process (Example 3 in Patent Publication No. CN119368560 A) to produce a copper-aluminum composite plate. The interfacial bonding strength of the copper-aluminum composite plate after diffusion heat treatment was 102 MPa.

[0074] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the 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 using laser, characterized in that: The steps include: S1, transporting the copper plate and 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 using a cold spraying device to obtain a preset intermediate layer, wherein the thickness of the preset intermediate layer is 0.15 to 0.4 mm; S3. Directly irradiating a laser beam onto the surface of the pre-deposited intermediate layer, the laser-irradiated Al-Cu-Mg-Si-Zr-Sc alloy layer is in a slightly molten state, and then rolling the copper-intermediate layer-aluminum composite plate under the rolling force of a rolling mill, so that the Al-Cu-Mg-Si-Zr-Sc alloy layer remains in the copper-aluminum laminate as an intermediate layer, and the rolling reduction rate of the rolling mill is 20-37%; S4, annealing and leveling the copper-aluminum laminated plate after rolling and laminating in a rolling mill to obtain a finished product; Wherein, 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 balance is Al; 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 balance is Al.

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 S3, the wavelength of the laser beam emitted by the laser is 450 nm, and the laser power during rolling and compounding is 700-1300 W.

3. The method for preparing a copper-aluminum laminated plate by laser-introducing an intermediate layer according to claim 2, characterized in that: During the rolling composite process, a rectangular light spot with uniform light spot energy distribution is used and irradiated onto the surface of the preset intermediate layer. The length direction of the rectangular light spot is the same as the width of the copper plate and aluminum plate to be composited.

4. The method for preparing a copper-aluminum laminated plate by laser-introducing an intermediate layer according to claim 3, characterized in that: The length of the rectangular spot is 25 to 40 mm and the width is 2 mm.

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

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

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

8. The method for preparing a copper-aluminum laminated plate by introducing an intermediate layer by laser 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 to 50 μm, the spraying distance during the cold spraying process is 20 to 30 mm, and the spraying angle is 90 degrees.

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