Copper-aluminum composite board prepared by means of molten aluminum continuous casting, and process thereof

Abstract

The present invention belongs to the technical field of composite boards. Provided are a copper-aluminum composite board prepared by means of molten aluminum continuous casting, and a process thereof. The process comprises: S1, heating an aluminum ingot to 700-800°C, and smelting same for 1-3 h; S2, subjecting the smelted molten aluminum to a degassing treatment, performing heat preservation, and leaving same to stand; S3, subjecting a copper strip to a texturing treatment, and then cleaning same; S4, heating the pretreated copper strip to 200-650°C; S5, continuously casting the treated molten aluminum on the treated copper strip under the protection of an inert gas, and subjecting the copper-aluminum composite material to quenching crystallization and anaerobic continuous casting; and S6, continuous rolling, which involves: rolling the continuously cast copper-aluminum composite material, so as to obtain a copper-aluminum composite board prepared by means of molten aluminum continuous casting. The copper-aluminum composite board prepared by means of molten aluminum continuous casting of the present invention improves the wettability of an aluminum and copper metal interface, and has high bonding strength, a small interface thickness, high composite strength, good mechanical properties, a low cost and a high efficiency, and same has wide use prospects.

Description

Copper-aluminum composite sheet prepared by continuous casting of aluminum liquid and process thereof Technical field:

[0001] The present invention relates to the technical field of composite plates, and in particular to a copper-aluminum composite plate material prepared by continuous casting of molten aluminum and a process thereof. Background technology:

[0002] Copper and aluminum are important nonferrous metals. Copper has excellent electrical and thermal conductivity, as well as corrosion resistance, while aluminum has excellent electrical and thermal conductivity. Compared to aluminum, copper is in short supply, while aluminum is more abundant, has a low specific gravity, and is inexpensive. Aluminum-copper composite sheet metal strip is a bimetallic material with an aluminum base and copper cladding. It combines the high electrical conductivity and low resource cost of aluminum with the high chemical stability and low contact resistance of copper, creating a new type of conductor and decorative material. Aluminum-copper composite sheet metal strip combines the advantages of both copper and aluminum. Using aluminum-copper composite sheet metal strip as a replacement for copper sheet metal is widely used in high-tech fields such as military, aerospace, computers, and electronic devices, as well as in the power, high- and low-voltage electrical equipment, automation, and construction industries, and is a current research hotspot in metal materials.

[0003] The international standard stipulates that the composite strength of copper-aluminum composite materials is ≥12kgf / cm. The existing lithium battery composite strength requirement for copper-aluminum composite materials is ≥15kgf / cm. With the continuous development of new energy technology, lithium batteries are the core energy storage devices in new energy, and copper-aluminum composite materials are the core component materials of lithium batteries. Therefore, lithium battery manufacturers have put forward higher requirements for the strength of copper-aluminum composite materials.

[0004] Currently, the main methods for producing copper-aluminum composite plates and strips include solid-solid composite methods such as rolling composite, explosive composite, extrusion-drawing composite, and diffusion welding composite, and liquid-solid composite methods such as core filling continuous casting and dual-mold continuous casting. Solid-solid composite methods are generally backward, with low yields and unstable quality, making them unsuitable for continuous large-scale production. Therefore, liquid-solid composite methods have become a research focus. However, liquid-solid composite methods directly combine molten aluminum with copper plates, resulting in a very thick bonding interface layer. The thicker the bonding interface layer, the more intermetallic compounds there are, and the lower the strength of the composite plate and strip. Therefore, directly combining molten aluminum with copper plates results in a thicker bonding interface layer, resulting in a lower strength composite plate that cannot meet the requirements of use.

[0005] Chinese invention patent CN101758071B discloses a method for producing aluminum-copper composite metal strips using oxygen-free continuous casting and rolling. This method requires in-line polishing to remove the oxide layer before bonding the copper and aluminum. This process is complex and results in a relatively low bond strength of approximately 100 MPa. Summary of the invention:

[0006] The purpose of the present invention is to propose a copper-aluminum composite sheet prepared by continuous casting of aluminum liquid and a process thereof, which can be used to prepare poles of new energy batteries. Through the process of continuous casting and multiple rolling, the wettability of the interface between aluminum and copper metals is improved. The prepared composite sheet has high bonding strength, small interface thickness, high composite strength, good mechanical properties, simple preparation method, low cost, high efficiency, and broad application prospects.

[0007] The technical solution of the present invention is achieved as follows:

[0008] The present invention provides a process for preparing copper-aluminum composite sheets by continuous casting of molten aluminum, comprising the following steps:

[0009] S1. Melting: Heat the aluminum ingot to 700-800℃ and melt for 1-3h;

[0010] S2. Standing: Degas the aluminum liquid after smelting in step S1 and let it stand for 10-30min;

[0011] S3. Copper strip pretreatment: roughening the copper strip and then cleaning it;

[0012] S4 copper strip heating: the pretreated copper strip obtained in step S3 is heated to 200-650 ℃;

[0013] S5 continuous casting: Under inert gas protection, the aluminum liquid treated in step S2 is continuously cast on the copper strip treated in step S4, the copper-aluminum composite material is quenched and crystallized, and oxygen-free continuous casting is performed;

[0014] S6. Continuous rolling: rolling the copper-aluminum composite material continuously cast in step S5 to obtain molten aluminum and continuously cast the copper-aluminum composite sheet.

[0015] As a further improvement of the present invention, the texturing treatment in step S3 includes mechanical texturing, chemical texturing or laser texturing, wherein the mechanical texturing is texturing using a steel brush or a sand belt; and the cleaning is ultrasonic cleaning or laser cleaning.

[0016] As a further improvement of the present invention, the casting speed in step S5 is 200-1200 mm / min; the casting width is 10-100 mm; the casting thickness is 3-20 mm, and the cooling rate of the rapid cooling crystallization is 100-150°C / min. The specific method is as follows: under the protection of inert gas, the copper strip treated in step S4 is continuously passed through the crystallizer of the continuous casting equipment, and the aluminum liquid is continuously cast on the copper strip through the casting system. The crystallizer performs rapid cooling and crystallization on the copper-aluminum composite material, and performs oxygen-free continuous casting.

[0017] As a further improvement of the present invention, the thickness of the copper-aluminum composite sheet prepared by continuous casting of the aluminum liquid in step S6 is 2-12 mm, the rolling pressure is 5000-5000000 N, the rolling speed is 300-1500 mm / min, and the rolling tension is 10000-200000 N.

[0018] As a further improvement of the present invention, in step S2, Cu@Si@Al Janus nanosheets are added before the degassing treatment, and the added amount is 5-7wt% of the aluminum liquid. The preparation method of the Cu@Si@Al Janus nanosheets is as follows:

[0019] T1. Preparation of SiO2 hollow nanospheres: Dissolve ethyl orthosilicate in an organic solvent to obtain an oil phase; dissolve an emulsifier in water to obtain an aqueous phase; dropwise add the aqueous phase to the oil phase, emulsify, adjust the solution pH to 10-11, heat and stir to react, centrifuge, wash, dry, and calcine to obtain SiO2 hollow nanospheres;

[0020] T2 ball milling: The SiO2 hollow nanospheres obtained in step T1 were ball milled to obtain SiO2 nanosheets;

[0021] T3 modification: The SiO2 nanosheets obtained in step T2 were added to ethanol, a silane coupling agent was added, the reaction was heated with stirring, centrifuged, washed, and dried to obtain modified SiO2 nanosheets;

[0022] T4. Preparation of copper oxide @ SiO2 @ alumina nanosheets: Aluminum isopropoxide was dissolved in dichloromethane and allowed to stand. The modified SiO2 nanosheets prepared in step T3 were added and allowed to float on the interface. An aqueous solution containing a copper salt was then added dropwise. Citric acid was then added and the mixture was allowed to stand for reaction. The mixture was centrifuged, washed, dried, and calcined to produce copper oxide @ SiO2 @ alumina nanosheets.

[0023] T5. Reduction: The copper oxide@SiO2@alumina nanosheets prepared in step T4 are mixed with magnesium powder, heated for reduction reaction, and then subjected to hydrogen reduction reaction to obtain Cu@Si@Al Janus nanosheets.

[0024] As a further improvement of the present invention, the mass ratio of the tetraethyl orthosilicate, the organic solvent, the emulsifier, and the water in step T1 is 12-15:100:0.5-1:30-50, the emulsifier is selected from at least one of Tween-20, Tween-40, Tween-60, and Tween-80, the temperature of the heating and stirring reaction is 50-60°C, the time is 10-12h, the temperature of the calcination is 300-500°C, and the time is 1-3h; the time of the ball milling in step T2 is 2-4h; the mass ratio of the SiO2 nanosheets and the silane coupling agent in step T3 is 100:22-25, the silane coupling agent is a silane coupling agent with an amino group, selected from at least one of KH550, KH602, and KH792, the temperature of the heating and stirring reaction is 40-50°C, and the time is 0.5-1h.

[0025] As a further improvement of the present invention, the mass ratio of the modified SiO2 nanosheets, aluminum isopropoxide, copper salt, and citric acid in step T4 is 50:12-15:7-12:3-5, the standing reaction time is 30-50 min, the calcination temperature is 500-700°C, and the time is 1-3 h. The copper salt is selected from at least one of copper chloride, copper sulfate, and copper nitrate; the mass ratio of copper oxide @ SiO2 @ alumina nanosheets and magnesium powder in step T5 is 100:7-12, the heating reduction reaction temperature is 700-800°C, the time is 0.5-1 h, the hydrogen reduction reaction temperature is 600-800°C, the time is 1-2 h, and the hydrogen ventilation rate is 20-30 mL / min.

[0026] As a further improvement of the present invention, after the cleaning treatment in step S3, a layer of ethylene glycol dimethyl ether solution of 11-mercaptoundecanoic acid is coated on the surface with a concentration of 7-12 wt%.

[0027] The present invention further protects a copper-aluminum composite sheet prepared by continuous casting of aluminum liquid obtained by the above-mentioned preparation process.

[0028] The present invention further protects the use of the above-mentioned copper-aluminum composite sheet prepared by continuous casting of molten aluminum in the preparation of new energy battery poles.

[0029] The present invention has the following beneficial effects:

[0030] When the wettability between metal matrices is poor, interface defects such as interface pores and cracks will be generated between the metal matrices during the preparation process, which will lead to the formation of brittle phase compounds at the interface, reducing the bonding strength between the metals and thus affecting the performance of the alloy material.

[0031] The present invention prepares Cu@Si@Al Janus nanosheets. First, hollow silica nanospheres are prepared by an emulsion method. Under the action of ball milling, the nanosheets are broken to form nanosheets. Then, the surface of the nanosheets is modified by a silane coupling agent with an amino group. The nanosheets are added into an organic solvent and an aqueous solution. The modified silica nanosheets are dispersed at the oil-water interface. Aluminum isopropoxide is dissolved in the organic solvent, and a copper salt is dissolved in water. Under the action of the amino groups on the modified silica nanosheets, the aluminum isopropoxide adheres to the surface of the nanosheets. Under the catalytic action of a small amount of water, a sol-gel reaction occurs, thereby forming aluminum oxide fixed on the side of the nanosheets close to the oil layer. At the same time, copper ions are fixed on the amino groups on the side of the nanosheets close to the water layer under the complexation action of the amino groups. Citric acid is further added to form a gel. The nanosheets are separated and calcined to obtain copper oxide@SiO2@alumina nanosheets. After magnesium thermal reduction and hydrogen reduction, the Cu@Si@Al Janus nanosheets are obtained.

[0032] The present invention adds Cu@Si@Al Janus nanosheets to aluminum liquid, which automatically migrate to the aluminum-copper metal interface. The layer of aluminum on the nanosheets penetrates into the aluminum metal layer, and the layer of copper on the nanosheets penetrates into the copper metal layer. After rolling, the thickness of the interface layer is greatly reduced, and the pores or air gaps at the interface are also reduced, thereby improving the bonding strength and composite strength, and enhancing the mechanical properties of the resulting composite plate.

[0033] The present invention texturizes the copper strip to make its interface rough and enhance the interface bonding strength, and further coats a layer of 11-mercaptoundecanoic acid solution on the surface. Since the molecular structure of the 11-mercaptoundecanoic acid solution contains sulfur and carboxyl groups, the 11-mercaptoundecanoic acid solution has good surface activity, forms an organic-inorganic composite layer through in-situ reaction, improves the wettability and dispersibility of the metal interface, thereby significantly improving the infiltration and composite between the copper substrate and the aluminum substrate, and improving the interface bonding strength of the two.

[0034] The copper-aluminum composite sheet prepared by continuous casting of aluminum liquid prepared by the present invention can be used to prepare poles of new energy batteries. Through the process of continuous casting and multiple rolling, the wettability of the interface between aluminum and copper metals is improved. The prepared composite sheet has high bonding strength, small interface thickness, high composite strength, good mechanical properties, simple preparation method, low cost, high efficiency, and broad application prospects. Specific implementation method:

[0035] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0036] Preparation Example 1 Preparation of Cu@Si@Al Janus Nanosheets

[0037] Here’s how:

[0038] Preparation of SiO2 hollow nanospheres: 12 parts by weight of ethyl orthosilicate was dissolved in 100 parts by weight of dichloromethane to obtain an oil phase; 0.5 parts by weight of Tween-20 was dissolved in 30 parts by weight of water to obtain an aqueous phase; the aqueous phase was added dropwise to the oil phase, and emulsification was performed at 10,000 rpm for 15 minutes. The pH of the solution was adjusted to 10, and the mixture was heated to 50°C, stirred for 10 hours, centrifuged, washed, dried, and calcined at 300°C for 1 hour to obtain SiO2 hollow nanospheres.

[0039] T2 ball milling: The SiO2 hollow nanospheres obtained in step T1 were ball milled for 2h to obtain SiO2 nanosheets;

[0040] T3 modification: 100 parts by weight of the SiO2 nanosheets prepared in step T2 were added to 200 parts by weight of ethanol, 22 parts by weight of a silane coupling agent KH550 was added, heated to 40 ° C, stirred for 0.5h, centrifuged, washed, and dried to obtain modified SiO2 nanosheets;

[0041] T4. Preparation of copper oxide @ SiO2 @ alumina nanosheets: 12 parts by weight of aluminum isopropoxide was dissolved in 100 parts by weight of dichloromethane. The mixture was allowed to stand. 50 parts by weight of the modified SiO2 nanosheets prepared in step T3 were added. The mixture floated on the interface. 100 parts by weight of an aqueous solution containing 7 parts by weight of copper chloride was added dropwise. Then, 3 parts by weight of citric acid was added. The mixture was allowed to stand for 30 minutes, centrifuged, washed, dried, and calcined at 500°C for 1 hour to produce copper oxide @ SiO2 @ alumina nanosheets.

[0042] T5. Reduction: 100 parts by weight of the copper oxide @ SiO2 @ alumina nanosheets prepared in step T4 and parts by weight of magnesium powder were mixed, heated to 700°C, reduced for 0.5h, and then reduced at 600°C for 1h with hydrogen at a flow rate of 20mL / min to obtain Cu@Si@Al Janus nanosheets.

[0043] Preparation Example 2 Preparation of Cu@Si@Al Janus Nanosheets

[0044] Here’s how:

[0045] Preparation of SiO2 hollow nanospheres: 15 parts by weight of ethyl orthosilicate was dissolved in 100 parts by weight of dichloromethane to obtain an oil phase; 1 part by weight of Tween-40 was dissolved in 50 parts by weight of water to obtain an aqueous phase; the aqueous phase was added dropwise to the oil phase, and emulsified at 10,000 rpm for 15 minutes. The pH of the solution was adjusted to 11, heated to 60°C, stirred for 12 hours, centrifuged, washed, dried, and calcined at 500°C for 3 hours to obtain SiO2 hollow nanospheres.

[0046] T2 ball milling: The SiO2 hollow nanospheres obtained in step T1 were ball milled for 4h to obtain SiO2 nanosheets;

[0047] T3 modification: 100 parts by weight of the SiO2 nanosheets prepared in step T2 were added to 200 parts by weight of ethanol, 25 parts by weight of a silane coupling agent KH602 was added, heated to 50 ° C, stirred for 1h, centrifuged, washed, and dried to obtain modified SiO2 nanosheets;

[0048] T4. Preparation of copper oxide @ SiO2 @ alumina nanosheets: 15 parts by weight of aluminum isopropoxide was dissolved in 100 parts by weight of dichloromethane. The mixture was allowed to stand. 50 parts by weight of the modified SiO2 nanosheets prepared in step T3 were added. The mixture floated on the interface. 100 parts by weight of an aqueous solution containing 12 parts by weight of copper sulfate was added dropwise. Then, 5 parts by weight of citric acid was added. The mixture was allowed to react for 50 minutes, centrifuged, washed, dried, and calcined at 700°C for 3 hours to produce copper oxide @ SiO2 @ alumina nanosheets.

[0049] T5. Reduction: 100 parts by weight of the copper oxide @ SiO2 @ alumina nanosheets prepared in step T4 and 12 parts by weight of magnesium powder were mixed, heated to 800°C, reduced for 1 hour, and then reduced at 800°C for 2 hours with hydrogen at a flow rate of 30 mL / min to obtain Cu@Si@Al Janus nanosheets.

[0050] Preparation Example 3 Preparation of Cu@Si@Al Janus Nanosheets

[0051] Here’s how:

[0052] Preparation of SiO2 hollow nanospheres: 13 parts by weight of ethyl orthosilicate was dissolved in 100 parts by weight of dichloromethane to obtain an oil phase; 0.7 parts by weight of Tween-80 was dissolved in 40 parts by weight of water to obtain an aqueous phase; the aqueous phase was added dropwise to the oil phase, and emulsification was performed at 10,000 rpm for 15 minutes. The pH of the solution was adjusted to 10.5, and the mixture was heated to 55°C and stirred for 11 hours. The mixture was centrifuged, washed, dried, and calcined at 400°C for 2 hours to obtain SiO2 hollow nanospheres.

[0053] T2 ball milling: The SiO2 hollow nanospheres obtained in step T1 were ball milled for 3h to obtain SiO2 nanosheets;

[0054] T3 modification: 100 parts by weight of the SiO2 nanosheets obtained in step T2 were added to 200 parts by weight of ethanol, 23 parts by weight of a silane coupling agent was added, heated to 45 ° C, stirred for 1h, centrifuged, washed, and dried to obtain modified SiO2 nanosheets;

[0055] T4. Preparation of copper oxide @ SiO2 @ alumina nanosheets: 13 parts by weight of aluminum isopropoxide was dissolved in 100 parts by weight of dichloromethane. The mixture was allowed to stand. 50 parts by weight of the modified SiO2 nanosheets prepared in step T3 were added. The mixture floated on the interface. 100 parts by weight of an aqueous solution containing 10 parts by weight of copper nitrate was added dropwise. Then, 4 parts by weight of citric acid was added. The mixture was allowed to stand for 40 minutes, centrifuged, washed, dried, and calcined at 600°C for 2 hours to produce copper oxide @ SiO2 @ alumina nanosheets.

[0056] T5. Reduction: 100 parts by weight of the copper oxide @ SiO2 @ alumina nanosheets prepared in step T4 and 10 parts by weight of magnesium powder were mixed, heated to 750°C, reduced for 1 hour, and then reduced at 700°C for 1.5 hours with hydrogen at a flow rate of 25 mL / min to obtain Cu@Si@Al Janus nanosheets.

[0057] Comparative Preparation Example 1

[0058] Compared with Preparation Example 3, the difference is that step T3 is not performed.

[0059] Here’s how:

[0060] Preparation of SiO2 hollow nanospheres: 13 parts by weight of ethyl orthosilicate was dissolved in 100 parts by weight of dichloromethane to obtain an oil phase; 0.7 parts by weight of Tween-80 was dissolved in 40 parts by weight of water to obtain an aqueous phase; the aqueous phase was added dropwise to the oil phase, and emulsification was performed at 10,000 rpm for 15 minutes. The pH of the solution was adjusted to 10.5, and the mixture was heated to 55°C and stirred for 11 hours. The mixture was centrifuged, washed, dried, and calcined at 400°C for 2 hours to obtain SiO2 hollow nanospheres.

[0061] T2 ball milling: The SiO2 hollow nanospheres obtained in step T1 were ball milled for 3h to obtain SiO2 nanosheets;

[0062] T3. Preparation of copper oxide @ SiO2 @ alumina nanosheets: 13 parts by weight of aluminum isopropoxide was dissolved in 100 parts by weight of dichloromethane. The mixture was allowed to stand. 50 parts by weight of the SiO2 nanosheets prepared in step T2 were added and allowed to float on the interface. 100 parts by weight of an aqueous solution containing 10 parts by weight of copper nitrate was then added dropwise. Then, 4 parts by weight of citric acid was added. The mixture was allowed to react for 40 minutes, centrifuged, washed, dried, and calcined at 600°C for 2 hours to produce copper oxide @ SiO2 @ alumina nanosheets.

[0063] T4. Reduction: 100 parts by weight of the copper oxide @ SiO2 @ alumina nanosheets prepared in step T3 and 10 parts by weight of magnesium powder were mixed, heated to 750°C, reduced for 1 hour, and then reduced at 700°C for 1.5 hours with hydrogen at a flow rate of 25 mL / min to obtain Cu@Si@Al Janus nanosheets.

[0064] Comparative Preparation Example 2

[0065] Compared with Preparation Example 3, the difference is that step T5 is not performed.

[0066] Here’s how:

[0067] Preparation of SiO2 hollow nanospheres: 13 parts by weight of ethyl orthosilicate was dissolved in 100 parts by weight of dichloromethane to obtain an oil phase; 0.7 parts by weight of Tween-80 was dissolved in 40 parts by weight of water to obtain an aqueous phase; the aqueous phase was added dropwise to the oil phase, and emulsification was performed at 10,000 rpm for 15 minutes. The pH of the solution was adjusted to 10.5, and the mixture was heated to 55°C and stirred for 11 hours. The mixture was centrifuged, washed, dried, and calcined at 400°C for 2 hours to obtain SiO2 hollow nanospheres.

[0068] T2 ball milling: The SiO2 hollow nanospheres obtained in step T1 were ball milled for 3h to obtain SiO2 nanosheets;

[0069] T3 modification: 100 parts by weight of the SiO2 nanosheets obtained in step T2 were added to 200 parts by weight of ethanol, 23 parts by weight of a silane coupling agent was added, heated to 45 ° C, stirred for 1h, centrifuged, washed, and dried to obtain modified SiO2 nanosheets;

[0070] T4. Preparation of copper oxide @ SiO2 @ alumina nanosheets: 13 parts by weight of aluminum isopropoxide was dissolved in 100 parts by weight of dichloromethane, and the mixture was allowed to stand. 50 parts by weight of the modified SiO2 nanosheets prepared in step T3 were added and allowed to float on the interface. 100 parts by weight of an aqueous solution containing 10 parts by weight of copper nitrate was then added dropwise. Then, 4 parts by weight of citric acid was added. The mixture was allowed to stand for 40 minutes, centrifuged, washed, dried, and calcined at 600°C for 2 hours to produce copper oxide @ SiO2 @ alumina nanosheets.

[0071] Example 1

[0072] This embodiment provides a process for preparing a copper-aluminum composite sheet by continuous casting of molten aluminum, comprising the following steps:

[0073] S1. Melting: Heat industrial LF21 pure aluminum ingot to 750℃ and melt for 2h;

[0074] S2. Standing: The aluminum liquid after smelting in step S1 is degassed and kept standing for 20 min;

[0075] S3. Copper strip pretreatment: 2 mm thick copper T2 strip was roughened with a steel brush and then ultrasonically cleaned for 10 min.

[0076] S4 copper strip heating: the pretreated copper strip obtained in step S3 is heated to 350 ℃;

[0077] S5 continuous casting: Under nitrogen protection, the copper strip treated in step S4 is continuously passed through the continuous casting equipment crystallizer, the aluminum liquid treated in step S2 is continuously cast on the copper strip through the casting system, the copper-aluminum composite material is quenched and crystallized in the crystallizer, and oxygen-free continuous casting is performed;

[0078] The casting speed is 1000 mm / min; the casting width is 50 mm; the casting thickness is 10 mm, and the cooling rate of the rapid cooling crystallization is 120°C / min;

[0079] S6 continuous rolling: the step S5 continuous casting copper-aluminum composite material is rolled to obtain molten aluminum continuous casting preparation of copper-aluminum composite sheet;

[0080] The thickness of the copper-aluminum composite sheet prepared by continuous casting of the aluminum liquid is 7 mm, the rolling pressure is 1,000,000 N, the rolling speed is 1,000 mm / min, and the rolling tension is 100,000 N.

[0081] Example 2

[0082] This embodiment provides a process for preparing a copper-aluminum composite sheet by continuous casting of molten aluminum, comprising the following steps:

[0083] S1. Melting: Heat industrial LF21 pure aluminum ingot to 750℃ and melt for 2h;

[0084] S2 standing: The Cu @ Si @ Al Janus nanosheets prepared in Preparation Example 1 were added to the molten aluminum after smelting in step S1, and the addition amount was 6wt% of the molten aluminum, stirred and mixed for 30min, degassed, and allowed to stand for 20min;

[0085] S3. Copper strip pretreatment: 2 mm thick copper T2 strip was roughened with a steel brush and then ultrasonically cleaned for 10 min.

[0086] S4 copper strip heating: the pretreated copper strip obtained in step S3 is heated to 300 ℃;

[0087] S5 continuous casting: Under nitrogen protection, the copper strip treated in step S4 is continuously passed through the continuous casting equipment crystallizer, the aluminum liquid treated in step S2 is continuously cast on the copper strip through the casting system, the copper-aluminum composite material is quenched and crystallized in the crystallizer, and oxygen-free continuous casting is performed;

[0088] The casting speed is 1000 mm / min; the casting width is 50 mm; the casting thickness is 10 mm, and the cooling rate of the rapid cooling crystallization is 120°C / min;

[0089] S6. Continuous rolling: rolling the copper-aluminum composite material continuously cast in step S5 to obtain a copper-aluminum composite sheet prepared by continuous casting of aluminum liquid.

[0090] The thickness of the copper-aluminum composite sheet prepared by continuous casting of the aluminum liquid is 7 mm, the rolling pressure is 1,000,000 N, the rolling speed is 1,000 mm / min, and the rolling tension is 100,000 N.

[0091] Example 3

[0092] This embodiment provides a process for preparing a copper-aluminum composite sheet by continuous casting of molten aluminum, comprising the following steps:

[0093] S1. Melting: Heat industrial LF21 pure aluminum ingot to 700℃ and melt for 1 hour;

[0094] S2 standing: The Cu @ Si @ Al Janus nanosheets prepared in Preparation Example 1 were added to the molten aluminum after smelting in step S1, added in an amount of 5wt% of the aluminum liquid, stirred and mixed for 30min, degassed, and allowed to stand for 10min;

[0095] S3 Copper strip pretreatment: The 2mm thick copper T2 copper strip was treated with a steel brush, and then ultrasonically cleaned for 10min, and the surface was coated with a layer of 11-mercaptoundecanoic acid in ethylene glycol dimethyl ether solution at a concentration of 7wt%;

[0096] S4 copper strip heating: the pretreated copper strip obtained in step S3 is heated to 350 ℃;

[0097] S5 continuous casting: Under nitrogen protection, the copper strip treated in step S4 is continuously passed through the continuous casting equipment crystallizer, the aluminum liquid treated in step S2 is continuously cast on the copper strip through the casting system, the copper-aluminum composite material is quenched and crystallized in the crystallizer, and oxygen-free continuous casting is performed;

[0098] The casting speed is 1000 mm / min; the casting width is 50 mm; the casting thickness is 10 mm, and the cooling rate of the rapid cooling crystallization is 100°C / min;

[0099] S6. Continuous rolling: rolling the copper-aluminum composite material continuously cast in step S5 to obtain a copper-aluminum composite sheet prepared by continuous casting of aluminum liquid.

[0100] The thickness of the copper-aluminum composite sheet prepared by continuous casting of the aluminum liquid is 7 mm, the rolling pressure is 1,000,000 N, the rolling speed is 1,000 mm / min, and the rolling tension is 100,000 N.

[0101] Example 4

[0102] This embodiment provides a process for preparing a copper-aluminum composite sheet by continuous casting of molten aluminum, comprising the following steps:

[0103] S1. Melting: Heat the aluminum ingot to 800℃ and melt for 3h;

[0104] S2 standing: The Cu @ Si @ Al Janus nanosheets prepared in Preparation Example 2 were added to the molten aluminum after smelting in step S1, added in an amount of 7wt% of the aluminum liquid, stirred and mixed for 30min, degassed, and allowed to stand for 30min;

[0105] S3 Copper strip pretreatment: The 2mm thick copper T2 copper strip was treated with a steel brush, and then ultrasonically cleaned for 10min, and the surface was coated with a layer of 11-mercaptoundecanoic acid in ethylene glycol dimethyl ether solution at a concentration of 12wt%;

[0106] S4 copper strip heating: the pretreated copper strip obtained in step S3 is heated to 350 ℃;

[0107] S5 continuous casting: Under nitrogen protection, the copper strip treated in step S4 is continuously passed through the continuous casting equipment crystallizer, the aluminum liquid treated in step S2 is continuously cast on the copper strip through the casting system, the copper-aluminum composite material is quenched and crystallized in the crystallizer, and oxygen-free continuous casting is performed;

[0108] The casting speed is 1000 mm / min; the casting width is 50 mm; the casting thickness is 10 mm, and the cooling rate of the rapid cooling crystallization is 150°C / min;

[0109] S6. Continuous rolling: rolling the copper-aluminum composite material continuously cast in step S5 to obtain a copper-aluminum composite sheet prepared by continuous casting of aluminum liquid.

[0110] The thickness of the copper-aluminum composite sheet prepared by continuous casting of the aluminum liquid is 7 mm, the rolling pressure is 1,000,000 N, the rolling speed is 1,000 mm / min, and the rolling tension is 100,000 N.

[0111] Example 5

[0112] This embodiment provides a process for preparing a copper-aluminum composite sheet by continuous casting of molten aluminum, comprising the following steps:

[0113] S1. Melting: Heat industrial LF21 pure aluminum ingot to 750℃ and melt for 2h;

[0114] S2 standing: The Cu @ Si @ Al Janus nanosheets prepared in Preparation Example 3 were added to the molten aluminum after smelting in step S1, added in an amount of 6wt% of the aluminum liquid, stirred and mixed for 30min, degassed, and allowed to stand for 20min;

[0115] S3 Copper strip pretreatment: The 2mm thick copper T2 copper strip was treated with a steel brush, and then ultrasonically cleaned for 10min, and the surface was coated with a layer of 11-mercaptoundecanoic acid in ethylene glycol dimethyl ether solution at a concentration of 10wt%;

[0116] S4 copper strip heating: the pretreated copper strip obtained in step S3 is heated to 350 ℃;

[0117] S5 continuous casting: Under nitrogen protection, the copper strip treated in step S4 is continuously passed through the continuous casting equipment crystallizer, the aluminum liquid treated in step S2 is continuously cast on the copper strip through the casting system, the copper-aluminum composite material is quenched and crystallized in the crystallizer, and oxygen-free continuous casting is performed;

[0118] The casting speed is 1000 mm / min; the casting width is 50 mm; the casting thickness is 10 mm, and the cooling rate of the rapid cooling crystallization is 120°C / min;

[0119] S6 continuous rolling: the step S5 continuous casting copper-aluminum composite material is rolled to obtain molten aluminum continuous casting preparation of copper-aluminum composite sheet;

[0120] The thickness of the copper-aluminum composite sheet prepared by continuous casting of the aluminum liquid is 7 mm, the rolling pressure is 1,000,000 N, the rolling speed is 1,000 mm / min, and the rolling tension is 100,000 N.

[0121] Comparative Example 1

[0122] Compared with Example 5, the difference is that the Cu@Si@Al Janus nanosheets are prepared by Comparative Preparation Example 1.

[0123] Comparative Example 2

[0124] Compared with Example 5, the difference is that the Cu@Si@Al Janus nanosheets are prepared by Comparative Preparation Example 2.

[0125] Test Example 1

[0126] The performance of copper-aluminum composite sheets prepared by continuous casting of aluminum liquid obtained in Examples 1-5 of the present invention and Comparative Examples 1-2, as well as similar commercial products, was tested. The results are shown in Table 1.

[0127] Table 1

[0128] As can be seen from the above table, the copper-aluminum composite sheets prepared by continuous casting of molten aluminum obtained in Examples 2-5 of the present invention have good bonding strength and composite strength, high shear strength and small interface layer thickness.

[0129] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A process for preparing copper-aluminum composite sheet by continuous casting of aluminum liquid, characterized in that: The following steps are involved: S1. Melting: Heat the aluminum ingot to 700-800℃ and melt for 1-3h; S2. Standing: Degas the aluminum liquid after smelting in step S1, keep it warm and stand it for 10-30 minutes; before degassing, add Cu@Si@Al Janus nanosheets in an amount of 5-7wt% of the aluminum liquid. The preparation method of the Cu@Si@Al Janus nanosheets is as follows: T1. Preparation of SiO2 hollow nano-microspheres: dissolving tetraethyl orthosilicate in an organic solvent to obtain an oil phase; dissolving an emulsifier in water to obtain an aqueous phase; dropping the aqueous phase into the oil phase, emulsifying, adjusting the solution pH to 10-11, heating and stirring to react, centrifuging, washing, drying, and calcining to obtain SiO2 hollow nano-microspheres; T2. Ball milling: The SiO2 hollow nanospheres prepared in step T1 were ball milled to obtain SiO2 nanosheets; T3 modification: the SiO2 nanosheets prepared in step T2 are added to ethanol, a silane coupling agent is added, the reaction is heated and stirred, centrifuged, washed, and dried to obtain modified SiO2 nanosheets; T4. Preparation of copper oxide @ SiO2 @ alumina nanosheets: dissolve aluminum isopropoxide in dichloromethane, let stand, add the modified SiO2 nanosheets prepared in step T3, float on the interface, drop an aqueous solution containing copper salt, then add citric acid, let stand to react, centrifuge, wash, dry, and calcine to obtain copper oxide @ SiO2 @ alumina nanosheets; T5. Reduction: The copper oxide @ SiO2 @ alumina nanosheets prepared in step T4 are mixed with magnesium powder, heated for reduction reaction, and then subjected to hydrogen reduction reaction to obtain Cu @ Si @ Al Janus nanosheets; S3. Pretreatment of the copper strip: roughening the copper strip and then cleaning it; S4. Copper strip heating: heating the pretreated copper strip obtained in step S3 to 200-650°C; S5. Continuous casting: Under the protection of inert gas, the aluminum liquid treated in step S2 is continuously cast on the copper strip treated in step S4, and the copper-aluminum composite material is quenched and crystallized, and oxygen-free continuous casting is performed; S6. Continuous rolling: rolling the copper-aluminum composite material continuously cast in step S5 to obtain a copper-aluminum composite sheet by continuous casting of aluminum liquid.

2. The process according to claim 1, characterized in that The texturing treatment in step S3 includes mechanical texturing, chemical texturing or laser texturing, wherein the mechanical texturing is texturing using a steel brush or a sand belt; and the cleaning is ultrasonic cleaning or laser cleaning.

3. The process according to claim 1, characterized in that The casting speed in step S5 is 200-1200 mm / min; the casting width is 10-100 mm; the casting thickness is 3-20 mm, and the cooling rate of the rapid cooling crystallization is 100-150°C / min. The specific method is as follows: under the protection of inert gas, the copper strip treated in step S4 is continuously passed through the crystallizer of the continuous casting equipment, the aluminum liquid is continuously cast on the copper strip through the casting system, the crystallizer performs rapid cooling and crystallization on the copper-aluminum composite material, and oxygen-free continuous casting is performed.

4. The process according to claim 1, characterized in that The thickness of the copper-aluminum composite sheet prepared by continuous casting of aluminum liquid in step S6 is 2-12 mm, the rolling pressure is 5000-5000000 N, the rolling speed is 300-1500 mm / min, and the rolling tension is 10000-200000 N.

5. The process according to claim 1, characterized in that The mass ratio of tetraethyl orthosilicate, organic solvent, emulsifier and water in step T1 is 12-15:100:0.5-1:30-50, the emulsifier is selected from at least one of Tween-20, Tween-40, Tween-60 and Tween-80, the temperature of the heating and stirring reaction is 50-60°C, the time is 10-12h, the temperature of the calcination is 300-500°C, and the time is 1-3h; the time of ball milling in step T2 is 2-4h; the mass ratio of SiO2 nanosheets and silane coupling agent in step T3 is 100:22-25, the silane coupling agent is a silane coupling agent with amino group, selected from at least one of KH550, KH602 and KH792, the temperature of the heating and stirring reaction is 40-50°C, and the time is 0.5-1h.

6. The process according to claim 1, characterized in that The mass ratio of the modified SiO2 nanosheets, aluminum isopropoxide, copper salt and citric acid in step T4 is 50:12-15:7-12:3-5, the static reaction time is 30-50min, the calcination temperature is 500-700°C, the time is 1-3h, and the copper salt is selected from at least one of copper chloride, copper sulfate and copper nitrate; the mass ratio of copper oxide @ SiO2 @ alumina nanosheets and magnesium powder in step T5 is 100:7-12, the heating reduction reaction temperature is 700-800°C, the time is 0.5-1h, the hydrogen reduction reaction temperature is 600-800°C, the time is 1-2h, and the hydrogen ventilation rate is 20-30mL / min.

7. The process according to claim 1, characterized in that After the cleaning treatment in step S3, a layer of ethylene glycol dimethyl ether solution of 11-mercaptoundecanoic acid is coated on the surface with a concentration of 7-12 wt %.

8. A copper-aluminum composite sheet prepared by continuous casting of aluminum liquid obtained by the process as described in any one of claims 1 to 7.

9. Use of the copper-aluminum composite sheet prepared by continuous casting of aluminum liquid as claimed in claim 8 in preparing new energy battery poles.

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