CN116815007A - Multi-strip silver-copper lateral composite strip for high-voltage fuse and preparation method thereof - Google Patents

Abstract

The invention discloses a plurality of silver-copper lateral composite strips for high-voltage fuses and a preparation method thereof, which includes: regulating the properties of pure copper and pure silver composite components through microalloying, improving the anti-oxidation performance of pure copper and using The deformation properties of the two components of silver and copper are closer. Microalloyed copper and pure silver are prepared into copper bars and silver bars through continuous casting, vacuum casting and rolling. Then the copper bars are slotted and silver alloy bars are composited. The interface is coated with organic additives to prepare a composite billet. After initial rolling in a two-roll mill, the bonding interface is in close contact, and then sintered in a protective atmosphere to form an interface layer on the composite interface. The sintered composite billet undergoes intermediate rolling, diffusion annealing, rolling, Multiple silver-copper lateral composite strips are prepared through heat treatment and finish rolling before the finished product; the copper strips are grooved along the length direction. The present invention uses an organic complexing agent to treat the silver-copper composite interface, which solves the problem of easy oxidation of the composite interface. The silver-copper composite interface is firmly bonded, has low equipment requirements, and is suitable for mass production.

Description

Multiple silver-copper lateral composite strips for high-voltage fuses and preparation method thereof

Technical field

The invention belongs to the technical field of composite material preparation, and specifically relates to a plurality of silver-copper lateral composite strips for high-voltage fuses and a preparation method thereof.

Background technique

A fuse is an electrical appliance that uses a metal conductor as a melt to protect the circuit. It is connected in series in the circuit. When overload or short-circuit current passes through the melt, the melt itself will heat up and fuse, thereby protecting the power system, various electrical equipment and household appliances.

Pure silver strip is a melt material with a high melting point that is widely used at present. Silver melt has good ability to break strong short-circuit current, and Ag has stable chemical properties, superior oxidation resistance and corrosion resistance, and has excellent resistance during use. The value is not easy to change and the melting point is stable, which is conducive to ensuring the stability and safety of the circuit. It is a key material for high-current and high-reliability fuses. However, in the long-term use process, especially the use of fuses in high and low voltage power distribution systems and new energy automobile industries, some shortcomings have gradually been exposed. On the one hand, pure silver is more expensive, making the cost of electrical products high; on the other hand, the cost of electrical products remains high; On the one hand, the pure silver material itself has a weak arc-extinguishing ability and needs to be filled with an arc-extinguishing medium. If the arc-extinguishing medium fails or is abnormal, there is a safety risk of fire or even explosion. At the same time, pure silver, as a melt material, has a high melting point and the temperature rises when the current is overloaded. The fuse is slow to rise. At the same time, the consumption of silver ribbon, the raw material for fast-acting fuses, has also increased dramatically, and the price has quadrupled in the past two years. This undoubtedly puts greater pressure on manufacturers, so manufacturers focus on finding new materials that are low-cost and do not affect the use characteristics. Therefore, developing a melt material with good electrical conductivity, strong arc extinguishing ability, low cost, suitable melting point and good processing performance has become an urgent engineering problem to be solved in fuse manufacturing.

In order to solve the problems exposed in the current use of melt materials, fuse manufacturers have proposed a variety of methods, such as using copper alloys and silver-copper alloys to replace pure silver strips, and also using the "metallurgical effect" to design low-melting point materials on the melt. For example, SnPb solder joints, when overloaded, the low-melting-point material melts and undergoes a metallurgical reaction with silver to produce a eutectic alloy with a lower melting point, which causes the pure silver melt to melt faster and the protection circuit to quickly disconnect. Although these methods have solved some problems, the problem of low reliability has still not been solved.

Contents of the invention

The present invention aims to overcome the above shortcomings and provide a plurality of silver-copper lateral composite strips for high-voltage fuses and a preparation method thereof. The composite interface of the silver-copper lateral composite strips is firmly combined, and the width of the silver strips is the same as that of the silver strips and the copper strips. The relative position accuracy is high, the rolling process is all cold rolling, the product batch stability is high, and the preparation process and equipment are simple, which solves the problem of unreliable silver-copper lateral composite interface bonding, silver bar width and relative position accuracy of silver bars and copper bars. To solve the problem of control, the multiple silver-copper lateral composite strips prepared have reliable composite interface combination and high dimensional accuracy, and can be widely used as melt materials for high-voltage rapid fuses in new energy vehicles and power distribution systems.

According to a first aspect, the present invention provides a plurality of silver-copper lateral composite strips for high-voltage fuses. The composite strips are prepared by the following method:

1. According to the following mass percentage ingredients and continuous casting process to smelt and cast the copper bars

(1) Ingredients

Ag: 0.05% ~ 0.1%, Ce: 0.01% ~ 0.05%, the balance is Cu;

(2) Cast copper row

Ce is added in the form of CuCe20 master alloy, using a rectangular high-purity graphite crystallizer for continuous casting. The width A of the copper bar is 50~250mm, and the thickness H is 15~40mm; then the machining method is used to produce silver bars in the length direction of the copper bar. The width and spacing require processing of 5 to 10 grooves. The width of the groove a is 2.5 to 4.5mm, and the depth h is 85% to 90% of the thickness H of the copper bar;

2. Use a vacuum induction furnace to melt and cast silver alloy ingots according to the following mass percentages:

(1) Ingredients

Cu: 0.1% ~ 0.3%, Ce: 0.01% ~ 0.05%, Sn: 0.05% ~ 0.1%, La: 0.01% ~ 0.05%, P: 0.001% ~ 0.01%, the balance is Ag;

(2) Cast silver alloy ingots

Cu, Ce, and La are added in the form of CuCeLa mixed rare earth master alloy, and P is added in the form of CuP master alloy. The ingot is melted and cast in a vacuum induction furnace. After hot extrusion, rolling, intermediate heat treatment, and finishing rolling, it is converted into silver bars. The thickness H1 is the width of the copper row groove a-0.03~0.1mm, and the width of the silver bar is the depth of the copper row groove h+0.05~0.2mm;

3. Add two or more organic acids such as malonic acid, malic acid, citric acid, tartaric acid, and stearic acid to ethylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether, propylene glycol, and butylcarbi. Heating and dissolving in two or more organic mixed solvents such as alcohol, the dissolving temperature is 50℃~70℃, after complete dissolution, add one or more additives such as diethanolamine, triethanolamine, castor oil, Siban 85, Tween 60, etc. , stir evenly and then cool it into a paste. Apply the paste additive on the surface of the copper row groove and the surface of the silver bar. Insert the silver bar coated with the organic additive into the copper row groove to assemble a silver-copper composite. blank;

4. Use a two-roller mill to roll the composite billet, with a total deformation of 5 to 10%;

5. The initially rolled composite billet is sintered in a tube furnace in a protective atmosphere. The sintering temperature is 600°C to 800°C, the holding time is 1 to 3 hours, and the protective atmosphere is one of nitrogen, argon and hydrogen;

6. The sintered composite billet is intermediate-rolled using a precision four-roller rolling mill. The deformation amount in each pass is 5% to 10%, and the total deformation amount is 40% to 70%;

7. The composite billet after intermediate rolling is diffusion annealed in a tube furnace in a protective atmosphere. The diffusion annealing temperature range is 400℃~700℃, the holding time is 0.5~4h, and the protective atmosphere is one of nitrogen, argon and hydrogen. Repeat the above steps 6 and 7, and after 3 to 5 times of annealing and rolling, roll to a thickness of 3.0 ^±0.1 mm;

8. Intermediate surface treatment and rolling: surface treatment of the diffusion annealed composite plate, using a strip grinder for surface treatment. After grinding, the bottom silver bar is exposed and the width of the silver bar is consistent with the front surface, and then welded using a spot welder. The lead strip is rolled with tension in a four-roll compact rolling mill, with a deformation of 10 to 20% in each pass. The total deformation between two annealings is controlled between 40% and 70%, and the tension is controlled between 1.5KN and 4KN. The braking speed is controlled between 5m/min and 20m/min;

9. Pre-finished product annealing and shearing: According to the finished product size, tensile strength, and hardness requirements, a vertical vacuum annealing furnace is used for pre-finished product heat treatment. A vacuum well-type furnace is used for pre-finished product annealing. The diffusion annealing temperature range is 400°C ~ 500°C. The heat preservation time is 0.5~2h, and the vacuum degree is less than 10 ^-1 Pa; before the finished product is cut, a precision strip cutting machine is used to cut the edges of the strip to ensure that the overall width of the strip and the width of the copper strips on both sides meet the requirements of the finished product. The strip shearing tension is controlled between 0.5KN and 1.5KN, and the rolling speed is controlled between 3m/min and 10m/min;

10. Finish rolling of finished products: using a precision six-roller rolling mill with tension rolling, the deformation of each pass is 5 to 10%, the total deformation is controlled between 40% and 60%, and the tension is controlled between 0.5KN and 1.5KN. The production speed is controlled between 3m/min and 10m/min. After the finished product is finished rolled, the head and tail are cut off, cleaned and inspected, and then packaged to obtain multiple silver-copper composite strip products.

Beneficial effects of the present invention:

This invention uses micro-alloying technology to control the performance of the silver-copper composite base material, coats the composite interface with an organic auxiliary agent to effectively remove the surface oxide film, and adopts a coated composite blank preparation technology + protective atmosphere sintering combined technology to make the silver-copper The composite interface realizes the coexistence and mutual promotion of the two mechanisms of physical and mechanical interlocking pinning and chemical element diffusion connection. The composite interface combination is strong and reliable. At the same time, it adopts a coating structure composite ingot structure. It avoids the need for silver bars and silver bars before finishing rolling. Due to the direct contact of the rollers, the silver bars are under three-way pressure during the rolling process, and the stress state is uniform, so that the stress states between multiple silver bars are basically the same, ensuring uniform deformation, thereby increasing the width of the silver bars and the thickness of the silver bars. , The relative position accuracy of the copper strips solves the problems of unreliable silver-copper lateral composite interface bonding, difficulty in controlling the width of the silver strips and the relative position accuracy of the silver strips and the copper strips. The multiple silver-copper lateral composite strips prepared are composite The interface combination is reliable and the dimensional accuracy is high. It can be widely used as melt material for high-voltage rapid fuses in new energy vehicles and power distribution systems.

Description of the drawings

The description and drawings are used to provide a further understanding of the present invention and constitute a part of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention.

Figure 1 is a physical diagram of five silver-copper lateral composite strips prepared in Example 1 of the present invention;

Figure 2 is a physical diagram of eight silver-copper lateral composite strips prepared by the method of the present invention.

Detailed ways

Example 1

The invention provides a method for preparing multiple silver-copper lateral composite strips for high-voltage fuses, which includes the following steps:

1. Use the continuous casting process to smelt and cast the copper bars according to the following mass percentage ingredients: Ag: 0.08% ~ 0.1%, Ce: 0.01% ~ 0.05%, the balance is Cu; Ce is added in the form of CuCe20 master alloy, using a rectangular height Continuous casting of pure graphite crystallizer, copper bar width A is 80 ^±0.5 mm, thickness H is 15 ^±0.1 mm; then use machining method to process 5 strips in the length direction of the copper bar according to the product silver bar width and spacing requirements Groove, the width a of the groove is 2.5 ^{± 0.05} mm, and the depth h is 12 ^{± 0.1} mm;

2. Use a vacuum induction furnace to melt and cast silver alloy ingots according to the following mass percentage ingredients: Cu: 0.1% ~ 0.3%, Ce: 0.01% ~ 0.05%, Sn: 0.05% ~ 0.1%, La: 0.01% ~ 0.05%, P: 0.001% ~ 0.01%, the balance is Ag; Cu, Ce, La are added in the form of CuCeLa mixed rare earth master alloy, P is added in the form of CuP10 master alloy, the ingot is melted and cast in a vacuum induction furnace, and then hot extruded, rolled, After intermediate heat treatment and finishing rolling, the silver bar is formed into silver bars. The thickness H1 of the silver bar is 2.45 ^±0.05 mm, and the width of the silver bar is 12.1 ^±0.1mm ;

3. Add two or more organic acids such as malonic acid, malic acid, citric acid, tartaric acid, and stearic acid to ethylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether, propylene glycol, and butylcarbi. Heating and dissolving in two or more organic mixed solvents such as alcohol, the dissolution temperature is 50°C, after complete dissolution, add two or more additives such as diethanolamine, triethanolamine, castor oil, Siban 85, Tween 60, etc. Stir evenly and then cool it into a paste. Apply the paste compounding agent on the surface of the groove of the copper row and the surface of the silver bar. Insert the silver bar coated with the organic compounding agent into the groove of the copper row to assemble a silver-copper composite. blank;

4. The composite billet is initially rolled using a two-roll mill, with a total deformation of 5 to 10%. The thickness of the composite billet after rolling is 14 ^±0.1 mm;

5. The initially rolled composite billet is sintered in a tube furnace in a protective atmosphere. The sintering temperature is 600°C, the holding time is 3 hours, and the protective atmosphere is hydrogen;

6. Use a precision four-roller rolling mill to intermediate-roll the sintered composite billet. The deformation amount in each pass is 5% to 10%, and the total deformation amount is 40%;

7. Diffusion anneal the intermediate-rolled composite billet in a tube furnace in a protective atmosphere. The diffusion annealing temperature is 400°C, the holding time is 4 hours, and the protective atmosphere is hydrogen; repeat the above steps 6 and 7, and after three times of annealing and rolling , rolled to a thickness of 3.0 ^±0.1 mm;

8. Intermediate surface treatment and rolling: surface treatment of the diffusion annealed composite plate, using a strip grinder for surface treatment. After grinding, the bottom silver bar is exposed and the width of the silver bar is consistent with the front surface, and then welded using a spot welder. The strip is led and rolled with tension in a four-roll compact rolling mill. The deformation in each pass is 10%. The total deformation between two annealings is controlled at 50%. The tension is controlled between 1.5KN and 2.0KN. The rolling speed is controlled at 5m. /min, after three times of annealing and rolling, rolled to a thickness of 0.2mm;

9. Annealing and shearing before finished products: According to the size, tensile strength, and hardness requirements of the finished products, a vertical vacuum annealing furnace is used for pre-finished product heat treatment. A vacuum well-type furnace is used for annealing before finished products. The annealing temperature is 400°C and the holding time is 0.5. The vacuum degree is less than 10 ^-1 Pa; a precision strip slitting machine is used to cut the edges of the strip before the finished product is cut to ensure that the overall width of the strip and the width of the copper strips on both sides meet the requirements of the finished product, and the strip cutting tension is controlled within Between 0.5KN and 1.5KN, the rolling speed is controlled between 3m/min and 10m/min;

10. Finish rolling of finished products: using a precision six-roller rolling mill with tension, the deformation of each pass is 5~10%, the total deformation is controlled at about 40%, the tension is controlled between 0.5KN~0.7KN, and the rolling speed is controlled at Between 3m/min and 4m/min, the thickness of the finished product after rolling is 0.11 ^±0.01 mm. After finishing rolling, the head and tail of the finished product are cut off, cleaned and inspected, and then packaged to obtain 5 silver-copper composite strip products (as shown in Figure 1) .

Example 2

The invention provides a method for preparing multiple silver-copper lateral composite strips for high-voltage fuses, which includes the following steps:

1. Use the continuous casting process to smelt and cast the copper bars according to the following mass percentage ingredients: Ag: 0.08% ~ 0.1%, Ce: 0.01% ~ 0.05%, the balance is Cu; Ce is added in the form of CuCe20 master alloy, using a rectangular height Continuous casting of pure graphite crystallizer, copper bar width A is 200 ^±1.0 mm, thickness H is 40 ^±0.1 mm; then use machining method to process 5 strips in the length direction of the copper bar according to the product silver bar width and spacing requirements Groove, the width a of the groove is 4.5 ^{± 0.05} mm, and the depth h is 36 ^{± 0.1} mm;

2. Use a vacuum induction furnace to melt and cast silver alloy ingots according to the following mass percentage ingredients: Cu: 0.1% ~ 0.3%, Ce: 0.01% ~ 0.05%, Sn: 0.05% ~ 0.1%, La: 0.01% ~ 0.05%, P: 0.001% ~ 0.01%, the balance is Ag; Cu, Ce, La are added in the form of CuCeLa mixed rare earth master alloy, P is added in the form of CuP10 master alloy, the ingot is melted and cast in a vacuum induction furnace, and then hot extruded, rolled, After intermediate heat treatment and finishing rolling, the silver bar is produced. The thickness H1 of the silver bar is 4.45 ^±0.05 mm, and the width of the silver bar is 36.2 ^±0.1mm ;

3. Add two or more organic acids such as malonic acid, malic acid, citric acid, tartaric acid, and stearic acid to ethylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether, propylene glycol, and butylcarbi. Heating and dissolving in two or more organic mixed solvents such as alcohol, the dissolving temperature is 70°C, after complete dissolution, add two or more additives such as diethanolamine, triethanolamine, castor oil, Siban 85, Tween 60, etc. Stir evenly and then cool it into a paste. Apply the paste compounding agent on the surface of the groove of the copper row and the surface of the silver bar. Insert the silver bar coated with the organic compounding agent into the groove of the copper row to assemble a silver-copper composite. blank;

4. The composite billet is initially rolled using a two-roll mill, with a total deformation of 5 to 10%. The thickness of the composite billet after rolling is 38 ^±0.2 mm;

5. The initially rolled composite billet is sintered in a tube furnace in a protective atmosphere. The sintering temperature is 770°C, the holding time is 0.5h, and the protective atmosphere is argon;

6. Use a precision four-roller rolling mill to intermediate-roll the sintered composite billet. The deformation amount in each pass is 5% to 10%, and the total deformation amount is 60%;

7. Diffusion anneal the intermediate-rolled composite billet in a tube furnace in a protective atmosphere. The diffusion annealing temperature is 600°C, the holding time is 4 hours, and the protective atmosphere is argon. Repeat the above steps 6 and 7, and after the second annealing and rolling , rolled to a thickness of 3.0 ^±0.1 mm;

8. Intermediate surface treatment and rolling: surface treatment of the diffusion annealed composite plate, using a strip grinder for surface treatment. After grinding, the bottom silver bar is exposed and the width of the silver bar is consistent with the front surface, and then welded using a spot welder. The strip is led and rolled with tension in a four-roll compact rolling mill. The deformation in each pass is 10%. The total deformation between two annealings is controlled at 50%. The tension is controlled between 1.5KN and 2.0KN. The rolling speed is controlled at 10m. /min, after three times of annealing and rolling, rolled to a thickness of 0.2mm;

9. Pre-finished product annealing and shearing: According to the finished product size, tensile strength, and hardness requirements, a vertical vacuum annealing furnace is used for pre-finished product heat treatment. The pre-finished product is annealed using a vacuum well-type furnace. The annealing temperature is 500°C and the holding time is 1 hour. The vacuum degree is less than 10 ^-1 Pa; a precision strip slitting machine is used to cut the edges of the strip before the finished product is cut to ensure that the overall width of the strip and the width of the copper strips on both sides meet the requirements of the finished product, and the strip cutting tension is controlled within Between 0.5KN and 1.0KN, the rolling speed is controlled between 8m/min and 10m/min;

10. Finishing rolling of finished products: using precision six-roller rolling mill with tension, the deformation of each pass is 5~10%, the total deformation is controlled at about 70%, the tension is controlled between 0.5KN~0.7KN, and the rolling speed is controlled at Between 8m/min and 10m/min, the thickness of the finished product after rolling is 0.05 ^±0.005 mm. After finishing rolling, the head and tail of the finished product are cut off, cleaned and inspected, and then packaged to obtain 10 silver-copper composite strip products.

Claims (10)

1. A multi-strip silver-copper lateral composite strip for a high-voltage fuse is characterized in that the composite strip is prepared by the following method:

slotting the microalloyed copper bar by adopting a machining method, coating an organic aid on a composite interface with a high-strength high-conductivity silver alloy bar to prepare a composite blank, performing initial rolling by adopting two rolling mills, closely contacting the composite interface, performing protective atmosphere sintering by adopting a tubular furnace to form an interface layer on the composite interface, and performing middle rolling, diffusion annealing, rolling, finished product pre-heat treatment and finish rolling on the sintered composite blank to prepare the silver-copper lateral composite strip;

the microalloyed copper bar comprises the following components in percentage by weight: 0.05 to 0.1 percent of Ag,0.01 to 0.05 percent of Ce and the balance of Cu; the micro-alloyed copper bar is prepared by adopting a continuous casting method, and the width of the copper bar is 50-250 mm and the thickness of the copper bar is 15-50 mm;

the high-strength high-conductivity silver strip comprises the following components in percentage by weight: 0.1 to 0.3 percent of Cu,0.01 to 0.05 percent of Ce,0.01 to 0.05 percent of Sn,0.01 to 0.05 percent of La,0.001 to 0.01 percent of P and the balance of Ag; the high-strength high-conductivity silver strip is smelted and cast in a vacuum medium-frequency induction furnace, and is subjected to hot extrusion and rolling to obtain the required silver strip, wherein the thickness H1 of the silver strip is the width a-0.03-0.05 mm of a copper bar groove, and the width of the silver strip is the depth h+0.05-0.2 mm of the copper bar groove; the copper bar is provided with grooves along the length direction, the number of the grooves is 5-10, the width a of each groove is 2.5-4.5 mm, and the depth H of each groove is 85-90% of the thickness H of the copper bar.

2. The method of preparing a plurality of silver-copper lateral composite strips for high voltage fuses according to claim 1, comprising the steps of:

step 1, proportioning according to the following mass percentages, and adopting a continuous casting process to cast copper bars in a continuous casting and smelting way:

and (3) batching: 0.05 to 0.1 percent of Ag,0.01 to 0.05 percent of Ce and the balance of Cu;

casting copper bars: ce is added in a CuCe20 intermediate alloy form, a rectangular high-purity graphite crystallizer is used for continuous casting, the width A of a copper bar is 50-250 mm, and the thickness H is 15-40 mm; then machining 5-10 grooves in the length direction of the copper bar according to the requirements of the product silver bar width and interval by adopting a machining method, wherein the width a of each groove is 2.5-4.5 mm, and the depth H is 85% -90% of the thickness H of the copper bar;

and 2, melting and casting silver alloy ingots by adopting a vacuum induction furnace according to the following weight percentages:

and (3) batching: wt.% of Cu:0.1 to 0.3 percent of Ce:0.01 to 0.05 percent of Sn, 0.05 to 0.1 percent of La, 0.01 to 0.05 percent of P and the balance of Ag;

casting silver alloy ingot: cu, ce and La are added in a CuCeLa mixed rare earth intermediate alloy form, P is added in a CuP intermediate alloy form, a vacuum induction furnace is adopted to smelt cast ingot, and silver strips are obtained through hot extrusion, rolling, intermediate heat treatment and finish rolling, wherein the thickness H1 of the silver strips is the width a-0.03-0.1 mm of a copper bar groove, and the width of the silver strips is the depth h+0.05-0.2 mm of the copper bar groove;

step 3, adding two or more of ethylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether, propylene glycol and butyl carbitol into two or more of malonic acid, malic acid, citric acid, tartaric acid and stearic acid, mixing, heating and dissolving, adding one or more additives of diethanolamine, triethanolamine, castor oil, span 85 and tween 60 after dissolving completely, stirring uniformly, cooling into paste, coating a paste auxiliary agent on the surface of a copper bar groove and the surface of the silver bar, and embedding the silver bar coated with the organic auxiliary agent into the copper bar groove to form a silver-copper composite blank;

step 4, the composite blank is initially rolled by adopting two rolling mills, and the total deformation is 5-10%;

step 5, sintering the composite blank subjected to blooming in a tube furnace protective atmosphere and preserving heat;

step 6, rolling the sintered composite blank in a precise four-bar rolling mill, wherein the pass deformation is 5% -10% and the total deformation is 40% -70%;

step 7, performing diffusion annealing and heat preservation on the intermediate rolled composite blank by adopting a tube furnace protective atmosphere, repeating the steps 6 and 7, and rolling to a thickness of 2.9-3.1 mm after 3-5 times of annealing and rolling;

step 8, intermediate surface treatment and rolling: carrying out surface treatment on the composite board after diffusion annealing, then welding a leading belt, adopting a four-rod compact rolling mill to carry out belt tension rolling, controlling the pass deformation between 10 and 20 percent and controlling the total deformation between two annealing to be between 40 and 70 percent;

step 9, annealing and shearing before finished products;

and step 10, finish rolling to obtain a plurality of silver-copper composite strip products.

3. The preparation method according to claim 2, characterized in that:

in step 3, the heating and dissolving are carried out at 50-70 ℃.

4. The preparation method according to claim 2, characterized in that:

in the step 5, the sintering temperature is 600-800 ℃, the heat preservation time is 1-3 h, and the protective atmosphere is one of nitrogen, argon and hydrogen.

5. The preparation method according to claim 2, characterized in that:

in the step 7, the diffusion annealing temperature ranges from 400 ℃ to 700 ℃, the heat preservation time ranges from 0.5h to 4h, and the protective atmosphere is one of nitrogen, argon and hydrogen.

6. The preparation method according to claim 2, characterized in that:

in step 8, a belt material grinding machine is adopted for surface treatment, and after grinding, the bottom silver strips are exposed, and the width of the silver strips is consistent with the width of the front face.

7. The preparation method according to claim 2, characterized in that:

in the step 8, the tension of the belt tension rolling is controlled between 1.5KN and 4KN, and the rolling speed is controlled between 5m/min and 20 m/min.

8. The method of claim 2, wherein in step 9, the pre-finish annealing comprises:

adopting a vertical vacuum annealing furnace to perform heat treatment before the finished product according to the requirements of the size, the tensile strength and the hardness of the finished product, adopting a vacuum pit furnace for annealing before the finished product, wherein the diffusion annealing temperature range is 400-500 ℃, the heat preservation time is 0.5-2 h, and the vacuum degree is less than 10 ^-1 Pa。

9. The method of claim 2, wherein in step 9, the finished product front-cutting comprises:

the accurate strip shearing machine is adopted to conduct shearing on the edge of the strip, the requirements of the composite finished product of the total width of the strip and the width of copper strips on two sides are guaranteed, the shearing tension of the strip is controlled between 0.5KN and 1.5KN, and the rolling speed is controlled between 3m/min and 10 m/min.

10. The method according to any one of claims 2 to 9, wherein in step 10, the finish rolling comprises:

the method comprises the steps of adopting a precise six-bar rolling mill to roll with tension, controlling the pass deformation to be 5-10%, controlling the total deformation to be 40-60%, controlling the tension to be 0.5 KN-1.5 KN, controlling the rolling speed to be 3-10 m/min, shearing off heads and tails after finish rolling, cleaning, inspecting and packaging to obtain a plurality of silver-copper composite strip products.