Method for preparing heterogeneous and isomeric double structures of a high-strength copper / steel composite plate

Abstract

The present invention discloses a preparation method for a heterogeneous - heterogeneous dual structure of a high - strength copper / steel composite plate. Through the synergistic effect of a laser energy field and rolling force, metallurgical bonding between copper and steel heterogeneous metals is achieved, and martensite structure is promoted to form near the composite interface. Subsequently, through online heat treatment of the steel - side surface with a flat - top laser beam, the complete transformation of the steel - side outer - layer structure into martensite, the transformation of martensite structure at the bonding interface into tempered sorbite, the reduction of residual stress on the copper side, and the formation of a heterogeneous structure with a gradient - distributed grain size on the copper side are synchronously realized, so as to synergistically improve the tensile strength, interface bonding strength, and toughness of the copper - steel composite plate.

Description

Technical Field

[0001] The present invention relates to the technical field of composite plate processing, and particularly relates to a preparation method for a heterogeneous - isomeric dual - structure of a high - strength copper / steel composite plate. Background Art

[0002] Heterogeneous metal composites effectively utilize the performance advantages of each constituent metal, while significantly reducing material costs, and have broad application prospects. Among them, copper - steel composite plates are metallurgically bonded copper and steel, combining the high electrical and thermal conductivity and corrosion resistance of copper, as well as the high strength, toughness and cost - effectiveness advantages of steel, and are widely used in power equipment, shipbuilding, chemical pipelines, new energy energy storage systems, etc.

[0003] Currently, the preparation process methods of copper - steel composite plates mainly include explosive cladding method, diffusion welding method, rolling method, etc. For example, the invention patent with the application number CN202410346392.0 proposes a preparation method for a copper - steel composite plate with a tensile strength exceeding 230 MPa. This method arranges explosives and uses the shock wave generated after detonation to instantaneously bond the two plates. This production process is simple, but it is not applicable to thin - gauge metal plates, and the strength of the prepared composite plate is still not high. The invention patent with the application number CN202411229580.1 proposes a copper - steel composite plate and its preparation method. This method prepares a copper - steel composite plate through a series of processes such as combining copper - steel billets, vacuum diffusion welding, heating, rolling, and heat treatment. However, the tensile strength of the copper - steel composite plate prepared by this method is only about 359 MPa. It can be found that the copper - steel composite plates prepared by existing processes generally have the problem of low strength and cannot meet the requirements for high - strength copper - steel composite plates in specific industrial environments. How to improve the strength of copper - steel composite plates while maintaining their excellent toughness and achieving short - process production is an urgent problem to be solved.

[0004] Therefore, the present invention proposes a preparation method for a heterogeneous - isomeric dual - structure of a high - strength copper - steel composite plate, which uses a one - step forming rolling composite + laser surface annealing treatment process under the action of laser - assisted heating, greatly improving the tensile strength of the copper - steel composite plate. Moreover, this preparation method is applicable to various thickness specifications and improves production efficiency at the same time. Summary of the Invention

[0005] In order to solve the problems existing in the above - mentioned background art, the present invention provides a preparation method for a heterogeneous - isomeric dual - structure of a high - strength copper - steel composite plate, which utilizes the synergistic effect of laser - induced thermal effect and rolling force to quickly and efficiently achieve the metallurgical lamination of copper plates (i.e., form a heterogeneous structure), and then uses laser surface annealing technology to simultaneously achieve micro - structure isomerization and residual stress elimination, synergistically improving the tensile strength, interfacial bonding strength and toughness of the composite plate.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] The present invention provides a method for preparing a heterogeneous - isomeric dual - structure of a high - strength copper - steel composite plate, comprising the following steps:

[0008] S1. Centering treatment: After uncoiling, the copper strip and the steel strip respectively enter the CPC system (automatic centering system for strip) through pinch rolls for centering treatment. The system uses a laser rangefinder or a photoelectric sensor to detect the edge position of the composite slab in real - time, calculates the deviation value between the current center line and the preset target center line, and the controller drives the servo motor to adjust the guide device through a PID + fuzzy hybrid algorithm (a combination of PID control and fuzzy logic control).

[0009] S2. Grinding treatment of the surfaces to be compounded: The surfaces to be compounded of the copper plate and the steel plate are subjected to surface roughening treatment. After the grinding treatment is completed, a dust adsorption system is used to remove the particles remaining on the surfaces to be joined.

[0010] S3. Rolling compound processing: Based on the synergistic effect of laser - assisted heating and mill reduction, metallurgical lamination of copper and steel is carried out, that is, a heterogeneous structure is formed.

[0011] Specifically, for the line - shaped light spot used in rolling compound processing, the energy distribution of the light spot shows a flat - top characteristic and has the characteristic of adjustable light - spot length. An opening is formed at the un - pressed part between the two plates. The flat - top line - shaped light spot irradiates the copper - steel interface to be compounded. At the same time, the highest laser - induced heating temperature on the steel side is controlled at 980 - 1130 °C, that is, ensuring that the surface layer near the bonding interface on the steel side undergoes austenitization; while the highest laser - induced heating temperature on the copper side is controlled at 900 - 1150 °C, that is, ensuring that the surface to be joined on the copper side is slightly melted or even not melted, so as to reduce the occurrence tendency of defects such as pores at the bonding interface. To improve the deformation coordination between dissimilar metals in the micro - region of the composite interface, the rotational speed ratio of the work rolls on the steel side and the copper side of the four - high asynchronous rolling mill is controlled at 1.1 - 1.5, and the speeds of the copper and steel strips uncoiled by the uncoiler are synchronously adjusted according to the requirements of the rolling compound process.

[0012] S4. Online laser surface heat treatment: The copper - steel composite plate after rolling compound enters the laser heat treatment chamber under inert gas protection, and a heterogeneous structure of tempered sorbite at the bonding interface and martensite on the outer surface is constructed on the steel side, and a heterogeneous structure with the grain size decreasing in a gradient from the bonding interface to the contact surface with the roll is constructed on the copper side.

[0013] Specifically, a flat-top wide light spot is used to irradiate the steel side surface of the copper-steel composite plate after rolling composite, synchronously achieving multiple effects such as annealing on the copper side, high-temperature tempering on the steel side, and surface hardening. On the one hand, through the heat conduction effect induced by the flat-top wide light spot irradiation on the steel side, annealing occurs on the copper side, with the highest heating temperature being 450 - 580°C, and the laser-induced annealing heating temperature showing a gradient distribution characteristic. At the same time, using the above annealing phenomenon, the residual stress on the copper side decreases, dislocations annihilate, and the plastic deformation ability is enhanced, and the grain size of copper near the bonding interface is relatively larger. On the other hand, the laser irradiation of the flat-top wide light spot on the outer surface of the steel will induce martensitic transformation within the depth range of 0.3 - 0.8 mm from the surface layer, and at the same time, perform high-temperature tempering treatment on the martensitic structure formed at the bonding interface during the rolling composite process, converting it into tempered sorbite structure.

[0014] Further, in the step S1, the deviation threshold between the center line of the plate and the preset target center line is 0.1 mm.

[0015] Further, in the step S2, a grinding roll is used for surface roughening treatment. The rotational speed of the grinding roll is adjustable within 500 - 3000 r / min, and the grinding roll can be made of materials such as wire brush, nylon brush, diamond-coated brush, etc.; the air volume Q of the dust adsorption system ≥ 10000 m 3 / h, the wind pressure P ≥ 10000 Pa, and the motor power P = 75 kW.

[0016] Further, in the step S2, the opening angle of the un-pressed part between copper and steel is 25 - 60°.

[0017] Further, in the step S3, the maximum laser output power is 40 kW, the length of the light spot is 200 - 600 mm, the width is 2 mm, and the uniformity of the light spot energy distribution ≥ 95%.

[0018] Further, in the step S3, the maximum rolling pressure of the four-high asynchronous rolling mill is 8000 kN, and the rolling reduction rate ≥ 50%.

[0019] Further, in the step S4, the maximum laser output power is 60 kW, the length of the homogenized light spot is 200 - 600 mm, the width is 5 mm, and the uniformity of the light spot energy distribution ≥ 95%.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] (1) By introducing a heterogeneous and isomeric dual structure, a significant improvement in tensile strength is achieved without changing the material composition. On the one hand, through the laser-assisted heating effect, the difference in plastic deformation ability in the micro-region of the bonding interface between copper and steel during the rolling composite process is reduced. At the same time, relying on the large rolling force, a laminated interface without defects such as pores is formed, effectively ensuring the tensile strength. On the other hand, by introducing an isomeric structure on the steel side (i.e., tempered sorbite at the bonding interface and martensite near the outer surface), and a gradient grain structure is formed on the copper side, combined with the coupling effect of the heterogeneous structure, a significant improvement in the strength of the composite plate is achieved based on the transformation-induced strengthening effect.

[0022] (2) The present invention proposes an on-line laser heat treatment method for copper-steel composite plates, which not only reduces the process flow and improves production efficiency, but also performs targeted heat treatment on each layer of metal through the gradient heating effect induced by laser heat treatment. That is, laser quenching is performed on the surface layer of the steel side to improve the surface wear resistance and play the role of the hard phase in the isomeric structure; high-temperature tempering is performed on the bonding interface layer of the steel side to soften the tissue and reduce the difference in deformation ability between dissimilar metals near the bonding interface; annealing is performed on the copper side to reduce the residual stress, construct a gradient grain structure, improve the tissue deformation ability, and ensure the toughness of the composite plate. Description of the Drawings

[0023] The present invention will be further described in detail below with reference to the drawings and specific embodiments.

[0024] Figure 1 It is a process flow chart for the preparation of the heterogeneous and isomeric dual structure of the high-strength copper-steel composite plate in the present invention. Detailed Embodiments

[0025] The technical solutions in the embodiments of the present invention will be clearly and completely described below 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 the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0026] Example 1

[0027] A preparation method for the heterogeneous-isomeric dual structure of a high-strength copper-steel composite plate includes the following steps:

[0028] S1. Centering treatment:

[0029] Using 2-mm-thick T2 copper and 2-mm-thick Q235 steel strips as the composite materials to be processed, with a width of 200 mm for both. After uncoiling, the copper strip and the steel strip are respectively fed into the CPC system through pinch rolls for centering treatment, and the deviation threshold between the center line of the plate and the preset target center line is 0.1 mm.

[0030] S2. Grinding treatment of the surfaces to be bonded:

[0031] The surfaces to be bonded of the copper plate and the steel plate are roughened using a grinding roller. The rotational speeds of the grinding motor sets cooperating with the grinding roller are adjusted respectively. The rotational speed for grinding the copper strip is 3000 r / min, and the rotational speed for grinding the steel strip is 500 r / min. After the grinding treatment, the particulate matter remaining on the surfaces to be joined is removed using a dust adsorption system. In the dust adsorption system, the air volume Q of the dust removal equipment is ≥ 10000 m 3 / h, the air pressure P is ≥ 10000 Pa, and the motor power P = 75 kW.

[0032] S3. Rolling composite processing:

[0033] Based on the synergistic effect of laser-assisted heating and mill roll reduction, metallurgical lamination of copper and steel is implemented, that is, a heterogeneous structure is formed. Laser parameters are set. Using the integral mirror spot shaping and homogenization mechanism, a flat-top spot with a length of 200 mm and a width of 2 mm is obtained. The laser output power is 25 kW, and the uniformity of the spot energy distribution is ≥ 95%. An opening with a 25° angle is formed between the unbonded parts of the two plates. The flat-top line spot is irradiated on the copper-steel interface to be bonded. At the same time, ensure that the highest heating temperature induced by the laser on the steel side is controlled at 1000 ± 20 °C, that is, ensure that the surface layer near the bonding interface on the steel side undergoes austenitization; while the highest heating temperature induced by the laser on the copper side is controlled at 925 ± 25 °C, that is, the surface to be bonded on the copper side undergoes micro-melting to reduce the occurrence tendency of defects such as pores at the bonding interface. Adjust the rotational speeds of the upper and lower rolls of the asynchronous mill. The rolling speed of the copper strip is adjusted to 0.2 m / min, and the rolling speed of the steel strip is adjusted to 0.3 m / min.

[0034] S4. Online laser surface heat treatment:

[0035] The copper-steel composite plate after rolling composite enters the laser heat treatment chamber under inert gas protection. A heterogeneous structure of tempered sorbite at the bonding interface and martensite on the outer surface is constructed on the steel side. Through the heat conduction effect induced by the flat-top wide spot irradiation on the steel side, ensure that the highest annealing temperature on the copper side is 480 ± 30 °C, and a heterogeneous structure with the grain size decreasing in a gradient from the bonding interface to the area near the roll contact surface is constructed on the copper side. The steel surface of the copper-steel composite plate after rolling composite is irradiated with a laser using a flat-top wide spot to simultaneously achieve multiple effects such as annealing on the copper side, high-temperature tempering on the steel side, and surface hardening. That is, a heterogeneous structure with an average grain size decreasing from 22 μm at the bonding interface to 4 μm near the roll contact surface is formed on the copper side, and a 0.3 mm thick martensite layer is obtained near the bonding interface on the steel side. Among them, the length of the spot is consistent with the width of the composite plate. The laser power is 30 kW, the length of the homogenized spot is 200 mm, the width is 5 mm, and the uniformity of the spot energy distribution is ≥ 95%.

[0036] The tensile strength test method is as follows: According to GB / T 228.1-2010 "Metallic materials - Tensile testing - Part 1: Method of test at room temperature", a tensile experiment is carried out on the copper-steel composite plate prepared in this embodiment on a universal material testing machine, so as to measure its tensile strength.

[0037] After testing, a T2 / Q235 composite plate with a tensile strength of 834 MPa is finally obtained.

[0038] Example 2

[0039] A preparation method for the heterogeneous - isomeric dual structure of a high-strength copper-steel composite plate includes the following steps:

[0040] S1. Centering treatment:

[0041] Using 0.8-mm-thick T2 copper and 1.5-mm-thick Q355 steel strip as the composite materials to be processed, with a width of 400 mm for both. After uncoiling, the copper strip and the steel strip enter the CPC system through pinch rolls for centering treatment respectively. The deviation threshold between the center line of the plate and the preset target center line is 0.1 mm.

[0042] S2. Grinding treatment of the surfaces to be composite:

[0043] The surfaces to be composite of the copper plate and the steel plate are roughened by a grinding roll. The rotational speeds of the grinding motor groups cooperating with the grinding roll are adjusted respectively. The rotational speed of the grinding copper strip is 1800 r / min, and the rotational speed of the grinding steel strip is 800 r / min. After the grinding treatment, the particulate matter remaining on the surfaces to be joined is removed by a dust adsorption system. In the dust adsorption system, the air volume Q of the dust removal equipment is ≥ 10000 m 3 / h, the air pressure P is ≥ 10000 Pa, and the motor power P = 75 kW.

[0044] S3. Rolling composite processing:

[0045] Based on the synergistic effect of laser-assisted heating and mill reduction, metallurgical lamination of copper and steel is carried out, that is, a heterogeneous structure is formed. Laser parameters are set. Using the integral mirror spot shaping and homogenization mechanism, a flat-top spot with a length of 400 mm and a width of 2 mm is obtained. The laser output power is 30 kW, and the uniformity of the spot energy distribution is ≥ 95%. An opening with a 40° angle is formed between the un-pressed parts of the two plates. The flat-top line spot irradiates the copper-steel interface to be composite. At the same time, ensure that the highest heating temperature induced by the laser on the steel side is controlled at 1050 ± 30 °C, that is, ensure that the surface layer near the bonding interface on the steel side undergoes austenitization; while the highest heating temperature induced by the laser on the copper side is controlled at 1080 ± 30 °C, that is, the surface to be joined on the copper side undergoes micro-melting to reduce the occurrence tendency of defects such as pores at the bonding interface. Adjust the rotational speeds of the upper and lower rolls of the asynchronous mill. The rolling speed of the copper strip is adjusted to 2.5 m / min, and the rolling speed of the steel strip is adjusted to 3 m / min.

[0046] S4. Online laser surface heat treatment:

[0047] The copper-steel composite plate after rolling composite enters the laser heat treatment chamber under inert gas protection, and a heterogeneous structure of tempered sorbite at the bonding interface and martensite on the outer surface is constructed on the steel side. Through the heat conduction effect induced by the flat-top wide-spot irradiation on the steel side, the highest annealing temperature on the copper side is ensured to be 500±30°C, and a heterogeneous structure with the grain size gradually decreasing from the bonding interface to the vicinity of the roll contact surface is constructed on the copper side. The steel surface of the copper-steel composite plate after rolling composite is irradiated by a flat-top wide spot, and multiple effects such as annealing on the copper side, high-temperature tempering on the steel side, and surface quenching are synchronously achieved. That is, a heterogeneous structure with the average grain size gradually decreasing from 25μm at the bonding interface to 5μm near the roll contact surface is formed on the copper side, and a 0.5mm-thick martensite layer is obtained near the bonding interface on the steel side. Among them, the length of the light spot is consistent with the width of the composite plate, the laser power is 40kW, the length of the homogenized light spot is 400mm, the width is 5mm, and the energy distribution uniformity of the light spot is ≥95%.

[0048] The tensile strength test method is as follows: According to GB / T 228.1-2010 "Metallic materials - Tensile testing - Part 1: Method of test at room temperature", the copper-steel composite plate prepared in this example is subjected to a tensile test on a universal material testing machine to measure its tensile strength.

[0049] After testing, a T2 / Q355 composite plate with a tensile strength of 974 MPa was finally obtained.

[0050] Example 3

[0051] A preparation method for a heterogeneous and isomeric dual-structure of a high-strength copper-steel composite plate, comprising the following steps:

[0052] S1. Centering treatment:

[0053] Taking 0.5mm-thick T2 copper and 1mm-thick Q690 steel as the composite materials to be processed, with a width of 600mm for both. After uncoiling, the copper strip and the steel strip enter the CPC system through pinch rolls for centering treatment, and the deviation threshold between the center line of the plate and the preset target center line is 0.1mm.

[0054] S2. Grinding treatment of the surfaces to be composite:

[0055] The surfaces to be composite of the copper plate and the steel plate are roughened by a grinding roll, and the rotation speeds of the grinding motor groups cooperating with the grinding roll are adjusted respectively. The rotation speed of the grinding copper strip is 1500 r / min, and the rotation speed of the grinding steel strip is 1000 r / min. After the grinding treatment, the particulate matter remaining on the surfaces to be bonded is removed by a dust adsorption system, and the air volume Q of the dust removal equipment in the dust adsorption system is ≥10000m3 / h, wind pressure P ≥ 10000 Pa, motor power P = 75 kW.

[0056] S3. Rolling composite processing:

[0057] Based on the synergistic effect of laser-assisted heating and rolling mill reduction, metallurgical lamination of copper and steel is carried out, that is, a heterogeneous structure is formed. Set the laser parameters, and use the integral mirror spot shaping and homogenization mechanism to obtain a flat-top spot with a length of 600 mm and a width of 2 mm. The laser output power is 40 kW, and the uniformity of the spot energy distribution ≥ 95%. An opening with a 60° angle is formed between the uncompacted parts of the two plates. The flat-top line spot is irradiated on the copper-steel interface to be compounded, and at the same time, ensure that the highest laser-induced heating temperature on the steel side is controlled at 1090 ± 40 °C, that is, ensure that the surface layer near the bonding interface on the steel side undergoes austenitization; while the highest laser-induced heating temperature on the copper side is controlled at 1100 ± 50 °C, that is, the surface to be bonded on the copper side undergoes micro-melting to reduce the occurrence tendency of defects such as pores at the bonding interface. Adjust the rotational speeds of the upper and lower rolls of the asynchronous rolling mill, and adjust the rolling speed of the copper strip to 2 m / min and the rolling speed of the steel strip to 2.2 m / min.

[0058] S4. Online laser surface heat treatment:

[0059] The copper-steel composite plate after rolling composite enters the laser heat treatment chamber under inert gas protection, and a heterogeneous structure of tempered sorbite at the bonding interface and martensite on the outer surface is constructed on the steel side. Through the heat conduction effect induced by the flat-top wide spot irradiation on the steel side, ensure that the highest annealing temperature on the copper side is 540 ± 40 °C, and a heterogeneous structure with the grain size decreasing in a gradient from the bonding interface to the vicinity of the roll contact surface is constructed on the copper side. Use the flat-top wide spot to irradiate the steel surface of the copper-steel composite plate after rolling composite, and simultaneously achieve multiple effects such as annealing on the copper side, high-temperature tempering and surface quenching on the steel side, that is, a heterogeneous structure with an average grain size decreasing in a gradient from 32 μm at the bonding interface to 6 μm near the roll contact surface is formed on the copper side, and a 0.8 mm thick martensite layer is obtained near the bonding interface on the steel side. Among them, the spot length is consistent with the width of the composite plate, the laser power is 60 kW, the length of the homogenized spot is 600 mm, the width is 5 mm, and the uniformity of the spot energy distribution ≥ 95%.

[0060] The tensile strength test method is as follows: According to GB / T 228.1-2010 "Metallic materials - Tensile testing - Part 1: Method of test at room temperature", a tensile test is carried out on the copper-steel composite plate prepared in this example on a universal material testing machine, and thus its tensile strength is measured.

[0061] After testing, a T2 / Q690 composite plate with a tensile strength of 1187 MPa is finally obtained.

[0062] Although embodiments of the present invention have been shown and described, those of ordinary skill in the art will appreciate 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 heterogeneous-heterogeneous dual structure of a high-strength copper / steel composite plate, characterized in that: The following steps are involved: S1. Centering treatment: After uncoiling, the copper strip and steel strip enter the CPC system through the pinch rollers for centering treatment; S2. Grinding treatment of the surface to be bonded: The surface to be bonded of the copper plate and the steel plate is subjected to surface roughening treatment. After the grinding treatment is completed, the particles remaining on the surface to be bonded are removed by using a dust adsorption system; S3, rolling composite processing: the unpressed part of the two plates is opened to form an opening, and the laser processing head outputs a flat-top line spot, which is irradiated on the interface between copper and steel to be composited. Then, the rolling mill is started, and the laser processing head emits light to heat the interface between the steel plate and the copper plate to be composited. Based on the synergistic effect of laser-assisted heating and rolling mill pressure, metallurgical lamination of copper and steel is implemented to form a heterogeneous structure; during laser irradiation, the maximum laser-induced heating temperature on the steel side is controlled at 980-1130°C, and the surface layer on the steel side close to the bonding interface is austenitized; while the maximum laser-induced heating temperature on the copper side is controlled at 900-1150°C, and the surface to be composited on the copper side is slightly melted or not melted; the rolling mill is a four-roll asynchronous rolling mill, and the speed ratio of the working rolls on the steel side and the copper side of the four-roll asynchronous rolling mill is controlled at 1.1-1.5, and the unwinding speeds of the copper strip and the steel strip are synchronously and collaboratively adjusted according to the requirements of the rolling composite process; S4. Online laser surface heat treatment: The copper-steel composite plate after rolling and compounding enters a laser heat treatment chamber under the protection of an inert atmosphere, and the steel side surface of the copper-steel composite plate after rolling and compounding is laser irradiated with a flat-top wide spot. The maximum annealing heating temperature of the copper side is 450-580°C, and the annealing temperature is gradiently distributed. The martensitic phase transformation is induced on the steel side within a depth range of 0.3-0.8 mm from the surface layer, and a heterogeneous structure of tempered troostite at the bonding interface and martensite on the outer surface is constructed on the steel side. On the copper side, a heterogeneous structure with a grain size that decreases gradually from the bonding interface to the surface layer near the copper side is constructed.

2. The method for preparing a heterogeneous-heterogeneous dual structure of a high-strength copper / steel composite plate according to claim 1, characterized in that: In the step S1, the deviation threshold between the center line of the plate and the preset target center line is 0.1 mm.

3. The method for preparing a heterogeneous-heterogeneous dual structure of a high-strength copper / steel composite plate according to claim 1, characterized in that: In step S2, a grinding roller is used for surface roughening treatment. The speed of the grinding roller is adjustable within 500 to 3000 r / min. The grinding roller is made of a wire brush, a nylon brush or a diamond coating brush. The air volume Q of the dust adsorption system is ≥ 10000m 3 / h, wind pressure P≥10000Pa, motor power P=75kW.

4. The method for preparing a heterogeneous-heterogeneous dual structure of a high-strength copper / steel composite plate according to claim 1, characterized in that: In step S3, the angle of the opening of the copper-steel plate at the unpressed portion is 25 to 60 degrees.

5. The method for preparing a heterogeneous-heterogeneous dual structure of a high-strength copper / steel composite plate according to claim 1, characterized in that: In step S3, the maximum output power of the laser is 40 kW, the length of the light spot is 200-600 mm, the width is 2 mm, and the uniformity of the light spot energy distribution is ≥95%.

6. The method for preparing a heterogeneous-heterogeneous dual structure of a high-strength copper / steel composite plate according to claim 1, characterized in that: In step S3, the maximum rolling pressure of the four-high asynchronous rolling mill is 8000 kN, and the rolling reduction ratio is ≥50%.

7. The method for preparing a heterogeneous-heterogeneous dual structure of a high-strength copper / steel composite plate according to claim 1, characterized in that: In step S4, the maximum output power of the laser is 60 kW, the length of the homogenized light spot is 200-600 mm, the width is 5 mm, and the uniformity of the light spot energy distribution is ≥95%.

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