A method for preparing a strong interfacial heterogeneous metal composite foil

Abstract

This invention belongs to the field of metal structural composite materials technology, specifically relating to a method for preparing a strong-interface heterogeneous metal composite foil. The method involves using a copper plate as a core, placing it in the center of a cold isostatically pressed square sheath, filling both sides of the copper plate with nickel powder, vacuum sealing the sheath, and obtaining a nickel-copper-nickel composite slab through cold isostatic pressing and vacuum sintering. The resulting nickel-copper-nickel composite foil is then obtained through hot rolling and cold rolling. This invention achieves a strong metallurgical bond at the atomic level through vacuum diffusion welding between the nickel powder and the copper plate. Vacuum removal of residual gases prevents bubble formation during foil rolling, significantly improving yield. The sintered nickel powder exhibits low deformation resistance, effectively reducing rolling force, lowering energy consumption, and improving production efficiency, making it a promising candidate for applications in the field of new energy battery electrodes.

Description

Technical Field

[0001] This invention belongs to the field of metal structure composite materials technology, specifically relating to a method for preparing a strong interface heterogeneous metal composite foil. Technical Background

[0002] Heterogeneous metal layered composite materials are a novel type of structural and functional material. They combine metal components with different physical and mechanical properties at the interface through composite technology, forming a strong bond that combines the excellent properties of each component metal. Nickel-copper bilayer metal composites are a high-performance electrode material for new energy batteries, currently produced via hot rolling composite technology. With the increasing demands for comprehensive performance in new energy batteries, nickel-copper-nickel trilayer heterogeneous metal composites are becoming a development trend. Traditional hot-rolled trilayer nickel-copper-nickel heterogeneous metal composites are prone to defects such as weak interfacial bonding and air bubbles during processing, leading to a significant decrease in yield. Although nickel plating can be achieved on both sides of copper plates and strips, the nickel layer is too thin to meet usage requirements, and electroplating technology is also environmentally polluting and energy-intensive. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a method for preparing a strong interfacial heterogeneous metal composite foil. The metal composite foil prepared by the method of this invention has good interfacial bonding, is easy to process and form, and is free of bubble defects. It can not only solve the problem of easy cracking between layers in traditional composite lamination, but also eliminate defects such as bubbles and improve the yield.

[0004] To achieve the above technical objectives, the technical solution adopted in this embodiment of the invention is: a method for preparing a strong interface heterogeneous metal composite foil, comprising the following steps:

[0005] (1) Preparation of nickel-copper-nickel composite green blank: A copper plate is placed in the center of a cold isostatic pressing square sleeve, nickel powder is filled on both sides of the copper plate, the sleeve is vacuum sealed, and a nickel-copper-nickel three-layer composite green blank is obtained by cold isostatic pressing.

[0006] (2) Sintering of nickel-copper-nickel composite green blanks: The above composite green blanks are placed in a vacuum sintering furnace and evacuated to 10°C. -1 ~10 -3 Pa, held at 850~1050 ℃ for 1~5 h to obtain nickel-copper-nickel composite sintered billet;

[0007] (3) Preparation of nickel-copper-nickel composite foil: The obtained nickel-copper-nickel composite sintered billet is preheated at 800~1000 ℃ for 1~3 h, hot rolled and then bright annealed, and then cold rolled in multiple passes to obtain nickel-copper-nickel composite foil.

[0008] Further, in step (1), the surface of the copper plate is sandblasted, and the surface roughness of the copper plate after sandblasting is 20~75 μm.

[0009] Furthermore, the material of the cold isostatic pressing square sheath in step (1) is one of rubber, silicone and polyurethane.

[0010] Furthermore, the average particle size of the nickel powder in step (1) is 1~100 μm.

[0011] Furthermore, the vacuuming time in step (1) is 0.5~5 h.

[0012] Furthermore, the cold isostatic pressing pressure in step (1) is 100~500 MPa, and the holding time is 1~10 min.

[0013] Furthermore, in step (1), the nickel-copper-nickel three-layer composite green blank has symmetrical nickel layers on both sides, the nickel layers on both sides have the same mass, and the mass ratio of a single nickel layer to a copper plate is 1:1 to 5:1.

[0014] Furthermore, the relative density of the nickel layer in the nickel-copper-nickel composite sintered billet described in step (2) is 95%~99.5%.

[0015] Furthermore, the preheating atmosphere of the nickel-copper-nickel composite sintered billet in step (3) is one or more of hydrogen, nitrogen, argon, decomposed ammonia and natural gas.

[0016] Furthermore, the thickness of the nickel-copper-nickel composite foil in step (3) is 0.05~0.5 mm.

[0017] Compared with the prior art, the beneficial effects of the technical solution provided by the embodiments of the present invention are as follows:

[0018] 1. This invention achieves a strong metallurgical bond at the atomic level between nickel powder and copper plate through vacuum diffusion welding, resulting in high interfacial bonding strength. Vacuum sintering can remove residual gases, prevent the generation of bubbles in rolled foil, and significantly improve the yield.

[0019] 2. The nickel powder sintered body of the present invention has low deformation resistance, which can effectively reduce rolling force, low energy consumption, high production efficiency, low cost, and can realize continuous production. It has important application prospects in the field of new energy battery electrode sheets. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0021] Example 1

[0022] A method for preparing a strong interface heterogeneous metal composite foil includes the following steps:

[0023] (1) Preparation of nickel-copper-nickel composite green blank: A copper plate with a thickness of 50 mm was used as the core. The surface of the copper plate was sandblasted and the surface roughness was 75 μm. The sandblasted copper plate was placed in the center of a cold isostatic pressing square rubber sleeve. Nickel powder with an average particle size of 100 μm was filled on both sides of the copper plate. After vacuuming for 0.5 h, the sleeve was sealed. The nickel-copper-nickel three-layer composite green blank was obtained by cold isostatic pressing. The cold isostatic pressing pressure was 500 MPa and the holding time was 1 min.

[0024] (2) Sintering of nickel-copper-nickel composite green blanks: The above-mentioned nickel-copper-nickel three-layer composite green blanks are placed in a vacuum sintering furnace and evacuated to 10°C. -1 Pa was sintered at 1050 °C for 1 h to obtain a nickel-copper-nickel composite sintered billet, with a relative density of 95% for the nickel layer in the sintered billet.

[0025] (3) Preparation of nickel-copper-nickel composite foil: The prepared nickel-copper-nickel composite sintered billet was placed in a hydrogen atmosphere and preheated at 1000 ℃ for 1 h. After hot rolling, it was bright annealed and then cold rolled in multiple passes to obtain a nickel-copper-nickel composite foil with a thickness of 0.5 mm. The thicknesses of the nickel layer, copper layer and nickel layer in the nickel-copper-nickel composite foil were 0.2 mm, 0.1 mm and 0.2 mm, respectively. According to mechanical property testing, the tensile strength of the nickel-copper-nickel composite foil reached 465 MPa, and the interlayer bonding was tight, meeting the requirements of new energy battery electrodes.

[0026] Example 2

[0027] A method for preparing a strong interface heterogeneous metal composite foil includes the following steps:

[0028] (1) Preparation of nickel-copper-nickel composite green blank: A copper plate with a thickness of 30 mm was used as the core. The surface of the copper plate was sandblasted and the surface roughness was 20 μm. The sandblasted copper plate was placed in the center of a cold isostatic pressing square silicone sleeve. Nickel powder with an average particle size of 1 μm was filled on both sides of the copper plate. After vacuuming for 5 h, the sleeve was sealed and the nickel-copper-nickel three-layer composite green blank was obtained by cold isostatic pressing. The cold isostatic pressing pressure was 100 MPa and the holding time was 10 min.

[0029] (2) Sintering of nickel-copper-nickel composite green blanks: The above-mentioned nickel-copper-nickel three-layer composite green blanks are placed in a vacuum sintering furnace and evacuated to 10°C. -3 Pa was sintered at 850 °C for 5 h to obtain a nickel-copper-nickel composite sintered billet, with a relative density of 99.5% for the nickel layer in the sintered billet.

[0030] (3) Preparation of nickel-copper-nickel composite foil: The prepared nickel-copper-nickel composite sintered billet was placed in a natural gas atmosphere and preheated at 800 ℃ for 3 h. After hot rolling, it was bright annealed and then cold rolled in multiple passes to obtain a nickel-copper-nickel composite foil with a thickness of 0.3 mm. The thicknesses of the nickel layer, copper layer and nickel layer in the nickel-copper-nickel composite foil were 0.1 mm, 0.1 mm and 0.1 mm, respectively. According to mechanical property testing, the tensile strength of the nickel-copper-nickel composite foil reached 512 MPa, and the interlayer bonding was tight, which met the requirements of new energy battery electrode sheets.

[0031] Example 3

[0032] A method for preparing a strong interface heterogeneous metal composite foil includes the following steps:

[0033] (1) Preparation of nickel-copper-nickel composite green blank: A copper plate with a thickness of 30 mm was used as the core. The surface of the copper plate was sandblasted and the surface roughness was 45 μm. The sandblasted copper plate was placed in the center of a cold isostatic pressing square silicone sleeve. Nickel powder with an average particle size of 8 μm was filled on both sides of the copper plate. After vacuuming for 3 h, the sleeve was sealed and the nickel-copper-nickel three-layer composite green blank was obtained by cold isostatic pressing. The cold isostatic pressing pressure was 200 MPa and the holding time was 3 min.

[0034] (2) Sintering of nickel-copper-nickel composite green blanks: The above-mentioned nickel-copper-nickel three-layer composite green blanks are placed in a vacuum sintering furnace and evacuated to 10°C. -2 Pa was sintered at 950 °C for 3 h to obtain a nickel-copper-nickel composite sintered billet, with a relative density of 98.5% for the nickel layer in the sintered billet.

[0035] (3) Preparation of nickel-copper-nickel composite foil: The prepared nickel-copper-nickel composite sintered billet was placed in a nitrogen atmosphere and preheated at 900 °C for 2 h. After hot rolling, it was bright annealed and then cold rolled in multiple passes to obtain a nickel-copper-nickel composite foil with a thickness of 0.05 mm. The thicknesses of the nickel layer, copper layer and nickel layer in the nickel-copper-nickel composite foil were 0.02 mm, 0.01 mm and 0.02 mm, respectively. According to mechanical property testing, the tensile strength of the nickel-copper-nickel composite foil reached 648 MPa, and the interlayer bonding was tight, meeting the requirements of new energy battery electrodes.

[0036] This invention uses a copper plate as the core, placed in the center of a cold isostatic pressing square sheath, fills both sides of the copper plate with nickel powder, vacuum seals the sheath, and obtains a nickel-copper-nickel composite slab through cold isostatic pressing and vacuum sintering. The nickel-copper-nickel composite foil is then obtained through hot rolling and cold rolling.

[0037] This invention ensures the formability of nickel-copper-nickel composite green blanks by comprehensively coordinating key parameters such as nickel powder particle size and cold isostatic pressing pressure. If any one of these parameters is not selected properly, not only will the nickel layer itself delaminate and crack, but significant delamination will also occur between the nickel layer and the copper plate.

[0038] In the sintering process of this invention, strict control of vacuum level and sintering temperature is required to obtain nickel-copper-nickel composite foil with tensile strength meeting the requirements of new energy battery electrode sheets. If the vacuum level is too low, residual gas cannot be eliminated; if the sintering temperature is too low, there will be more residual pores in the nickel layer, which will easily cause cracks during rolling; if the sintering temperature is too high, a liquid phase will easily appear between the copper plate and the nickel layer, resulting in severe shrinkage and deformation.

[0039] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for preparing a strong interfacial heterogeneous metal composite foil, characterized in that, Includes the following steps: (1) Preparation of nickel-copper-nickel composite green blank: A copper plate is placed in the center of a cold isostatic pressing square sleeve, nickel powder is filled on both sides of the copper plate, the sleeve is vacuum sealed, and a nickel-copper-nickel three-layer composite green blank is obtained by cold isostatic pressing. (2) Sintering of nickel-copper-nickel composite green blanks: The above composite green blanks are placed in a vacuum sintering furnace and evacuated to 10°C. -1 ~10 -3 Pa, held at 850~1050 ℃ for 1~5 h to obtain nickel-copper-nickel composite sintered billet; (3) Preparation of nickel-copper-nickel composite foil: The obtained nickel-copper-nickel composite sintered billet is preheated at 800~1000 ℃ for 1~3h, hot rolled and then bright annealed, and then cold rolled in multiple passes to obtain nickel-copper-nickel composite foil; In step (1), the average particle size of the nickel powder is 1~100 μm; the cold isostatic pressing pressure is 100~500 MPa, and the holding time is 1~10 min.

2. The method for preparing a strong interface heterogeneous metal composite foil according to claim 1, characterized in that, In step (1), the surface of the copper plate is sandblasted, and the surface roughness of the copper plate after sandblasting is 20~75 μm.

3. The method for preparing a strong interface heterogeneous metal composite foil according to claim 1, characterized in that, The material of the cold isostatic pressing square sheath mentioned in step (1) is one of rubber, silicone and polyurethane.

4. The method for preparing a strong interface heterogeneous metal composite foil according to claim 1, characterized in that, The vacuuming time mentioned in step (1) is 0.5~5 h.

5. The method for preparing a strong interface heterogeneous metal composite foil according to claim 1, characterized in that, In step (1), the nickel-copper-nickel three-layer composite green blank has symmetrical nickel layers on both sides, the nickel layers on both sides have the same mass, and the mass ratio of a single nickel layer to a copper plate is 1:1 to 5:

1.

6. The method for preparing a strong interface heterogeneous metal composite foil according to claim 1, characterized in that, The relative density of the nickel layer in the nickel-copper-nickel composite sintered billet described in step (2) is 95%~99.5%.

7. The method for preparing a strong interface heterogeneous metal composite foil according to claim 1, characterized in that, The preheating atmosphere of the nickel-copper-nickel composite sintered billet in step (3) is one or more of hydrogen, nitrogen, argon, decomposed ammonia and natural gas.

8. The method for preparing a strong interface heterogeneous metal composite foil according to claim 1, characterized in that, The thickness of the nickel-copper-nickel composite foil in step (3) is 0.05~0.5 mm.