Copper-steel composite material, preparation method thereof and electrical contact assembly

Abstract

The invention provides a copper-steel composite material, a preparation method thereof and an electrical contact assembly, and the preparation method comprises the following steps: providing a copper substrate material, and grooving the upper surface of the copper substrate material to form a groove; embedding a steel core material into the groove, then covering the steel core material and the copper substrate material with a copper top material, and then carrying out composite rolling to obtain an integral material; carrying out heat treatment on the integral material; performing multi-pass cold rolling-annealing on the material subjected to heat treatment to obtain a copper-steel composite material strip; and the copper-steel composite material strip is subjected to striping treatment, and the coated copper-steel composite material is obtained. According to the invention, the problems of pitting corrosion, rusting and the like of the material caused by the fact that the Fe element of the copper-steel composite material is exposed in the air can be effectively prevented, the corrosion resistance of the copper-steel composite electrical contact assembly and the electrical product thereof is remarkably improved, and the yield and the production efficiency of the electrical contact assembly are greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of electrical components, and in particular to a copper-steel composite material and a preparation method thereof, and an electric contact assembly. Background Art

[0002] Circuit breakers, contactors and other low-voltage electrical appliances, especially those with high current ratings, mostly use copper-clad steel as the supporting material for their electrical contacts. Copper-clad steel has high strength and high plasticity, good electrical conductivity, and the magnetic element Fe in the middle layer can guide the direction of the arc. However, since the copper-clad steel support is made by punching, the two side walls of the support are punched sections, and the Fe in the middle layer is usually exposed to the air, which is very prone to pitting and rust. Rust blocks can easily fall off, causing the internal mechanism of the electrical appliance to get stuck and fail, and are also easily adsorbed on the electrical contacts, affecting the direction of the arc, thereby affecting the electrical life of the electrical product.

[0003] After searching, it was found that patent CN102126112A discloses a method for preparing an electromagnetic shielding multilayer composite material in an electric vacuum device, which uses Cu / Fe / Cu rolled by large deformation. However, the composite material Fe of this method is exposed to the air, especially in a humid environment, which significantly reduces the service life of the electrical appliance.

[0004] Patent CN114864305A uses punching from the thicker copper layer to the thinner copper layer, so that the thicker copper layer sidewalls wrap the Fe layer on both sides of the composite strip. However, when the iron layer is thicker than the copper layer, this method has the risk of incomplete wrapping of the Fe layer by the copper layer sidewalls, so that part of the Fe is also exposed to the air, and pitting failure still occurs.

[0005] Patent CN105161380A discloses a circuit breaker electrical contact support and a preparation method thereof, which uses a Cu / Fe / Cu composite strip inlaid with a copper block to replace traditional products. However, the magnetic element Fe contained in the support material is exposed to the air, bringing the risk of affecting the arc direction and the service life of the electrical appliance.

[0006] In order to prevent Fe from being exposed to the air, the prior art adopts a method of electroplating pure silver or other materials on the surface of the copper-clad steel electrical contact assembly. However, when this method is actually used, there is a problem that it is not easy to electroplate silver on the surface of the Fe layer.

[0007] Therefore, it is necessary to develop a copper-steel composite material that can effectively prevent pitting and rust of the iron layer in the middle layer of the contact bridge of electrical contacts for circuit breakers and other electrical appliances, so as to solve the above technical problems. Summary of the invention

[0008] In view of the defects in the prior art, an object of the present invention is to provide a copper-steel composite material and a preparation method thereof and an electrical contact assembly.

[0009] According to a first aspect of the present invention, a method for preparing a copper-steel composite material is provided, the method comprising:

[0010] Providing a copper base material, and performing a groove process on the upper surface of the copper base material to form a groove;

[0011] The steel core material is embedded in the groove, and then the copper top material is covered on the steel core material and the copper base material, and then composite rolling is performed to obtain an integral material;

[0012] heat treating the entire material;

[0013] The heat-treated material is subjected to multiple cold rolling-annealing steps to obtain a copper-steel composite material strip;

[0014] The copper-steel composite material strip is processed into strips to obtain a coated copper-steel composite material.

[0015] Optionally, the upper surface of the copper base material is grooved to form a groove, wherein the groove is a long strip-shaped through groove running through the length direction of the copper base material, or a plurality of rectangular pits along the length direction of the copper base material.

[0016] Optionally, the steel core material is placed in the groove, wherein:

[0017] The width of the steel core material is 0.01 mm to 0.1 mm greater than the width of the groove; the height of the steel core material is 0.05 mm to 0.2 mm greater than the depth of the groove.

[0018] Optionally, the step of covering the copper top material on the steel core material and the copper base material and then performing composite rolling comprises:

[0019] Covering the steel core material and the copper base material with a copper top material to form a first composite material;

[0020] The first composite material is placed in the positioning groove of the special-shaped rolling roller group, and is cold-compounded with a 30% to 70% deformation reduction using a special-shaped rolling mill at room temperature and in an atmospheric environment.

[0021] Optionally, the step of covering the copper top material on the steel core material and the copper base material and then performing composite rolling comprises:

[0022] Covering the steel core material and the copper base material with a copper top material, and reinforcing and welding the two ends of the copper base material and the copper top material to form a second composite material;

[0023] The second composite material is placed in the positioning groove of the special-shaped roller group, and then hot-rolled composite rolling is performed with a special-shaped roller machine under a protective atmosphere or a vacuum atmosphere with a deformation reduction of 30% to 70%.

[0024] Optionally, the upper roller and the lower roller of the special-shaped roller group are respectively provided with positioning grooves, and the width of the positioning grooves matches the width of the first composite material or the second composite material, so that the first composite material or the second composite material does not expand laterally during rolling, and the composite interface is subjected to lateral force, thereby promoting close bonding of the copper-steel composite interface.

[0025] Optionally, the whole material is heat treated, including: placing the whole material in a continuous annealing furnace, introducing a reducing gas, and performing heat treatment; wherein the heat treatment temperature is 300°C to 900°C, and the pulling speed of the strip is 0.1m / min to 10m / min.

[0026] Optionally, the heat-treated material is subjected to multiple cold rolling-annealing processes, wherein: the deformation amount of each cold rolling process is 10% to 30%; the annealing temperature is 300° C. to 800° C., the annealing time is 0.1 h to 10 h, and the annealing atmosphere is a protective atmosphere.

[0027] According to a second aspect of the present invention, there is provided a copper-steel composite material, which is prepared by the above-mentioned method for preparing the copper-steel composite material, and the copper-steel composite material comprises a copper base material, a steel core material and a copper top material, wherein a groove is provided on one side of the copper base material, the shape of the steel core material matches the groove, the steel core material is embedded in the groove, and the copper top material covers the steel core material and the upper surface of the groove; the copper base material, the steel core material and the copper top material are composited into one, the four side walls of the copper-steel composite material are coated with copper material, and the middle core is steel material.

[0028] According to a third aspect of the present invention, there is provided an electric contact assembly, comprising an electric contact and a support member, wherein the support member is made of the copper-steel composite material described in the second aspect, and the electric contact is disposed on a surface of the support member.

[0029] Compared with the prior art, the present invention has at least one of the following beneficial effects:

[0030] 1. The present invention first grooves the surface of the copper base material, then embeds the steel core material, and finally divides it into strips, so that the steel core of the middle layer of the copper-steel composite material is wrapped in the copper material, thereby effectively preventing the pitting and rust of the material caused by the Fe element of the copper-steel composite material being exposed to the air, and significantly improving the corrosion resistance of the copper-steel composite electrical contact assembly and its electrical products.

[0031] 2. The existing copper-clad steel electrical contact products have exposed Fe elements, so the electrical contact products need to be electroplated with silver in the subsequent process to prevent the iron from rusting. In addition, the iron layer is not easy to be electroplated with silver, which brings the risk of reduced yield of the electrical contact products. However, the copper-steel composite material prepared by the present invention has Fe elements that are not exposed to the air, and the electrical contact products do not need to be electroplated with silver, so they can prevent iron from rusting, which saves the production cost of electroplating silver and shortens the production process, thereby greatly improving the yield and production efficiency of the electrical contact assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0033] Figure 1 Schematic diagram of the explosion of the copper-steel composite strip before rolling in one embodiment of the present invention Figure 1 ;

[0034] Figure 2 The structure of the copper-steel composite material in one embodiment of the present invention is shown in FIG. Figure 1 ;

[0035] Figure 3 Schematic diagram of the explosion of the copper-steel composite strip before rolling in one embodiment of the present invention Figure 2 ;

[0036] Figure 4 This is a schematic diagram of the overall structure of a copper-steel composite material in one embodiment of the present invention;

[0037] Figure 5 The structure of the copper-steel composite material in one embodiment of the present invention is shown in FIG. Figure 2 ;

[0038] Figure 6 is a schematic structural diagram of an electric contact assembly in one embodiment of the present invention;

[0039] Figure 7 It is a partial structural schematic diagram of an electric contact assembly in one embodiment of the present invention;

[0040] Among them, 1-copper base material, 2-copper core material, 3-copper top material, 4-groove, 5-electric contact, 6-support part. DETAILED DESCRIPTION

[0041] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several variations and improvements may be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0042] An embodiment of the present invention provides a method for preparing a copper-steel composite material, the method comprising the following steps:

[0043] S1. providing a copper base material, and performing a groove process on the upper surface of the copper base material to form a groove;

[0044] S2, embedding the steel core material in the groove, and then covering the steel core material and the copper base material with the copper top material, and then performing composite rolling to obtain the overall material;

[0045] S3, heat treating the whole material;

[0046] S4, performing multiple cold rolling-annealing on the heat-treated material to obtain a copper-steel composite material strip;

[0047] S5. Slice the copper-steel composite material strip to obtain a coated copper-steel composite material.

[0048] In some embodiments, in step S1, the material of the copper base material is any one of pure copper, red copper, oxygen-free copper, copper alloy, composite copper material and dispersion-enhanced copper-based material. Several grooves are machined on the surface of the copper base material, and the surface of the base material is cleaned or brushed, wherein the groove is a long strip through groove that runs through the length direction of the copper base material. In the case of opening multiple grooves, the multiple grooves are arranged along the width direction of the material strip, and the processing rate is faster; or the groove is a plurality of rectangular pits along the length direction of the copper base material, and the pits are arranged along the rolling direction, and the arrangement method can be equidistant or non-equidistant. The depth, width and number of the grooves can be adjusted according to the different current levels of switching electrical appliances such as circuit breakers and the thickness ratio requirements of the finished copper-steel composite material.

[0049] In some embodiments, in step S2, the steel core material is made of iron, iron alloy, copper-clad steel, stainless steel, carbon steel, silicon steel, structural steel or alloy steel, and the shape of the steel core material matches the groove structure of the copper base material, and its geometric structure is a long strip or block-shaped rectangular parallelepiped. The width of the steel core material is 0.01mm to 0.1mm larger than the width of the groove to facilitate placing the steel core material at the bottom of the groove; the height of the steel core material is 0.05mm to 0.2mm larger than the depth of the groove. During rolling, the steel core material is extended laterally to the side wall of the groove, so that the steel / copper material fits tightly at the composite interface without defects such as delamination or gaps. The copper top material is made of any one of pure copper, red copper, oxygen-free copper, copper alloy, composite copper material and dispersion-enhanced copper-based material, covering the notch of the copper base material, and coating the copper base material and the steel core material.

[0050] In some optional embodiments, in step S2, the composite rolling adopts a cold rolling composite method, specifically, the copper top material is covered on the steel core material and the copper base material to form a first composite material; the first composite material is placed in a positioning groove of a special-shaped rolling roller group, and a special-shaped rolling mill is used to perform cold composite rolling with a deformation reduction of 30% to 70% at room temperature and atmospheric environment.

[0051] In some optional embodiments, in step S2, the composite rolling adopts a hot rolling composite method. Specifically, the copper top material is covered on top of the steel core material and the copper base material, and the two ends of the copper base material and the copper top material are reinforced and welded to form a second composite material; the second composite material is placed in the positioning groove of the special-shaped rolling roller group, and then a special-shaped rolling mill is used to perform hot rolling composite rolling with a deformation reduction of 30% to 70% in a protective atmosphere or a vacuum atmosphere.

[0052] In the above embodiment of the present invention, the deformation reduction is set so that the two materials are fully extruded and deformed at the Cu / Fe contact interface during rolling, and the fresh Cu / Fe interface forms a preliminary physical and mechanical bite. The cold rolling composite method is carried out below the recrystallization temperature, and the interface bonding is mainly enhanced by plastic deformation. The composite interface is flat and has no wave shape, stable performance, and easy to control size. The hot rolling composite method is carried out above the recrystallization temperature, and the bonding is enhanced by atomic diffusion at high temperature. The composite interface is wavy and has good machinability.

[0053] In the above embodiment of the present invention, the steel core material is placed in the groove of the copper base material, and then the copper top material is placed on the surface with the groove of the copper base material, and then a special-shaped roller group is used to perform composite rolling with a deformation reduction of 30% to 70%, thereby improving the copper-steel composite interface bonding strength. The upper roller and the lower roller surface of the special-shaped roller group are respectively provided with grooves to form positioning grooves, and the width (lateral dimension) of the positioning groove matches the width of the material to be rolled, that is, the first composite material or the second composite material. The roller positioning groove constrains the material to be rolled and limits the lateral expansion of the material, so that the first composite material or the second composite material does not expand laterally during rolling, and the composite interface is subjected to lateral force, which promotes the close bonding of the copper-steel composite interface.

[0054] In step S3, the heat treatment parameters are determined according to the interface bonding strength (the formation conditions of the diffusion interface). In some embodiments, the entire material is placed in a continuous annealing furnace, and a reducing gas is introduced to perform heat treatment; wherein the heat treatment temperature is 300°C to 900°C, and the pulling speed of the strip is 0.1m / min to 10m / min, thereby forming a good diffusion layer, so that the two layers of material form a firm bond.

[0055] In step S4, multiple cold rolling-annealing means cold rolling first and then annealing, and repeating it multiple times. The number of passes can be adjusted according to the plasticity and work hardening requirements of the material. After multiple rolling passes, the deformation of each pass is controlled at 10% to 30%, and the total deformation is controlled at 30% to 70%, thereby achieving the control of material thickness. The specific parameters of cold rolling-annealing are determined according to the interface bonding strength (the formation conditions of the diffusion interface) and the material work hardening requirements. In some embodiments, the deformation of each cold rolling is 10% to 30%; the annealing temperature is 300°C to 800°C, the annealing time is 0.1h to 10h, and the annealing atmosphere is a protective atmosphere, thereby forming a good diffusion layer, so that the two layers of materials form a firm bond, and effectively improve the cracking of the strip.

[0056] In some embodiments, in step S5, when step S1 opens a long strip-shaped through groove that passes through the two end surfaces of the copper base material, the stripping process refers to using any one of wire cutting, water cutting, plasma cutting and laser cutting to avoid the steel core material area, and stripping the heat-treated material along the rolling direction to obtain a copper-steel composite material with four side walls coated with copper material (no copper material at both ends) and a middle core of steel.

[0057] When step S1 opens a rectangular pit that runs through the two end faces of the copper base material, the stripping process refers to using any one of wire cutting, water cutting, plasma cutting and laser cutting to avoid the steel core material area, and stripping the heat-treated material along the rolling direction to obtain a copper-steel composite material with four side walls and two ends made of copper material (that is, the six outer surfaces are all covered with copper) and the middle core is steel. The copper-steel composite material has better anti-rust performance than the copper-steel composite material without copper material at both ends.

[0058] In the above embodiment of the present invention, the copper base material and the copper top material are made of copper material with good electrical conductivity, and the steel core material is made of high-strength steel material with magnetic elements, so that the copper-steel composite material realizes the complementary advantages of copper and steel materials, and has both the high electrical conductivity, high plasticity and high thermal conductivity of copper materials, and the high strength of steel materials. In addition, due to the presence of magnetic elements Fe, the arc direction can be guided, which is conducive to arc extinguishing. In addition, the copper materials of the copper base material and the copper top material fully cover the steel located in the center of the copper-steel composite material, so that the Fe element of the copper-steel composite material is not exposed to the air, which effectively solves the problems of poor corrosion resistance and easy rust of conventional copper-clad steel, thereby improving the service life of electrical products.

[0059] The copper-steel composite material prepared by the above-mentioned method for preparing the copper-steel composite material includes a copper base material, a steel core material and a copper top material, wherein a groove is provided on one side of the copper base material, the shape of the steel core material matches the groove, the steel core material is embedded in the groove, and the copper top material covers the steel core material and the upper surface of the groove; the copper base material, the steel core material and the copper top material are composited into one, the four side walls of the copper-steel composite material are coated with copper material, and the middle core is steel material.

[0060] like Figure 1 and Figure 2 A groove 4 is provided on the surface of the copper base material 1, and the groove 4 is a long strip through groove that runs through the length direction of the copper base material 1. The long strip of steel core material 2 is embedded in the groove 4, and the copper top material 3 covers the copper base material 1 and the steel core material 2. The copper base material 1, the steel core material 2, and the copper top material 3 are compounded by special-shaped rollers to obtain a copper-steel composite material with four side walls coated with copper material and a middle core of steel.

[0061] like Figure 3-Figure 5 A groove 4 is provided on the surface of the copper base material 1, and the groove 4 is a plurality of rectangular pits along the length direction of the copper base material 1. A plurality of block-shaped rectangular steel core materials 2 are respectively embedded in the groove 4. The copper top material 3 covers the copper base material 1 and the steel core material 2. The copper base material 1, the steel core material 2, and the copper top material 3 are compounded by special-shaped rollers to obtain a copper-steel composite material with four side walls and two ends being made of copper material and a middle core being made of steel.

[0062] Another embodiment of the present invention provides an electrical contact assembly, referring to Figure 6 and Figure 7 The electric contact assembly includes an electric contact 5 and a support member 6. The support member 6 is made by stamping and shaping the above-mentioned copper-steel composite material to obtain a copper-steel composite support member with four side walls made of copper material and a middle core made of steel material, or a copper-steel composite support member with four side walls and two ends made of copper material and a middle core made of steel material. The electric contact 5 is arranged on one surface of the support member 6. Exemplarily, the electric contact 5 is welded or riveted to one surface of the support member 6.

[0063] The method for preparing the electric contact assembly comprises the following steps:

[0064] S100: Punching and shaping the copper-steel composite material to obtain a copper-steel composite support member;

[0065] Specifically, the copper-steel composite material of the above-mentioned embodiment is punched and shaped by a punch press or the like to obtain a copper-steel composite support member whose side walls are coated with copper material, so that the iron element of the support member is not exposed to the air, thereby solving the problem that the iron layer of the existing copper-clad steel is easy to rust and difficult to be electroplated with pure silver.

[0066] S200: welding or riveting the support member and the electric contact to obtain the required copper-steel composite electric contact assembly.

[0067] The above-mentioned embodiment of the present invention adopts the method of limiting the positioning groove of the special-shaped roller, inlay compounding and striping to obtain the copper-steel composite material. Compared with the existing preparation method, the composite interface of the prepared material is subjected to lateral force, which promotes the close bonding of the silver-copper composite interface. The material has higher bonding strength, and the steel material located in the center of the material is coated with copper on its surface, so the prepared material has better rust and corrosion resistance. Therefore, the quality stability and product life of the electrical contact assembly prepared using the copper-steel composite material are significantly improved. The method of the above-mentioned embodiment of the present invention has a simple processing method, does not require additional silver electroplating, is easy to mass produce, has a high yield rate, and has stable performance, which can greatly reduce the production cost of the product.

[0068] The scheme of the present application will be explained below in conjunction with specific embodiments. It will be appreciated by those skilled in the art that the following embodiments are only used to illustrate the present application and should not be considered as limiting the scope of the present application. If specific techniques or conditions are not indicated in the embodiments, the techniques or conditions described in the documents in this area or the product specifications are carried out. The reagents used or the instruments that do not indicate the manufacturer are all conventional products that can be obtained through commercial channels.

[0069] Example 1

[0070] This embodiment provides Figure 1 and Figure 2 The preparation method of the Cu-Fe composite material shown comprises the following steps:

[0071] S1: Multiple rectangular pits are machined on the surface of the pure copper strip along the length direction of the strip, and the surface of the copper strip is cleaned to remove oxides, oil stains, etc. The depth of the pits is 70% of the total thickness of the copper strip;

[0072] S2: The Fe block is embedded in the pit on the surface of the base copper strip, and then a layer of pure copper thin strip is applied on the top surface of the base copper strip embedded with the Fe block. Then, the two ends of the base copper strip and the top thin copper strip are reinforced and welded by laser welding. Then, the pure copper strip embedded with the Fe block and covered with the top thin copper strip is placed in the positioning groove of the special-shaped roller group, and then H 2 The hot rolling composite rolling with 60% deformation reduction is carried out by using a special-shaped roller mill under a protective atmosphere; wherein the width of the Fe block is 0.05 mm greater than the width of the copper strip pit, and the height of the Fe block is 0.2 mm greater than the depth of the copper strip pit;

[0073] Among them, the special-shaped roller group refers to the upper roller and the lower roller in contact with the pure copper strip to be rolled, each of which is provided with a positioning groove, and the width of the positioning groove matches the width of the pure copper strip to be rolled, so that the pure copper strip to be rolled is constrained during rolling and does not expand laterally, which also makes the Cu-Fe composite interface subject to lateral force, promoting the close bonding of the composite interface;

[0074] S3: Place the strip obtained in S2 in a continuous annealing furnace and pass H 2 , heat treatment is performed; wherein the heat treatment temperature is 845°C and the strip pulling speed is 3m / min;

[0075] S4: The heat-treated strip is subjected to several cold rolling-annealing passes to be rolled to a desired thickness to obtain a Cu-Fe composite strip; wherein the deformation amount of each cold rolling pass is 15%; the annealing temperature of each pass is 600°C, the annealing time is 3h, and the annealing atmosphere is H 2 atmosphere;

[0076] S5: Plasma cutting is used to avoid the Fe block area and to cut the heat-treated composite strip into strips along the rolling direction of the strip to obtain a Cu-Fe composite strip embedded with a plurality of Fe blocks.

[0077] Furthermore, the material is used to prepare a Cu-Fe composite electrical contact assembly, comprising the following steps:

[0078] The Cu-Fe composite material strip prepared in the above steps is punched and shaped by a high-speed punching machine to obtain a Cu-Fe composite support member with four side walls and two ends being Cu and a middle core being Fe;

[0079] The Ag / CdO electrical contact is welded to the surface of the Cu-Fe composite support to obtain a Cu-Fe composite electrical contact assembly whose punched sections are all coated with copper, thereby solving the problem that the iron layer of the existing copper-clad steel is prone to rust and difficult to be electroplated with pure silver.

[0080] Example 2

[0081] This embodiment provides Figure 3-Figure 5 The preparation method of the H90-low carbon steel composite material shown comprises the following steps:

[0082] S1: Two rectangular grooves penetrating the two end surfaces of the base material are machined on the surface of the H90 copper strip along the length direction of the strip, and the copper strip is surface treated to remove oxides, oil stains, etc. The groove depth is 80% of the total thickness of the copper strip;

[0083] S2: embedding a low-carbon steel bar in the groove on the surface of the copper strip, then coating the surface of the copper strip with the embedded steel bar with a layer of H90 thin copper, then placing it in the positioning groove of the special-shaped roller group, and then performing cold composite rolling with a 50% deformation reduction using a special-shaped roller group with positioning grooves on both the upper and lower rollers at room temperature and atmospheric environment; wherein the width of the steel bar is 0.02 mm larger than the width of the copper strip groove, and the height of the steel bar is 0.1 mm larger than the depth of the copper strip groove;

[0084] S3: Place the material obtained in S2 in a continuous annealing furnace and introduce H 2 , heat treatment is performed; wherein the heat treatment temperature is 790°C and the strip pulling speed is 5m / min;

[0085] S4: The heat-treated material is subjected to several cold rolling-annealing passes to be rolled to a desired thickness to obtain a copper-steel composite strip; wherein the deformation amount of each cold rolling pass is 10%; the annealing temperature of each pass is 550°C, the annealing time is 2h, and the annealing atmosphere is H 2 atmosphere;

[0086] S5: The heat-treated material, i.e., the copper material between two steel bars avoiding the steel bar area, is cut into strips along the rolling direction of the material strip by wire cutting to obtain a copper-steel composite material with four side walls coated with copper material and a middle core of steel.

[0087] Furthermore, the material is used to prepare an H90-low carbon steel composite electrical contact assembly, comprising the following steps:

[0088] The copper-steel composite material prepared in the above steps is punched and shaped by a high-speed punching machine to obtain a copper-steel composite support member with four side walls made of copper material and a middle core made of steel material;

[0089] Ag / SnO 2The electric contact is welded to the surface of the support to obtain a copper-steel composite electric contact assembly.

[0090] The copper-steel composite electrical contact assembly sample prepared in Example 1 was compared with the existing electrical contact assembly made of conventional copper-clad steel (CN114864305A) to evaluate the material composite interface peeling strength and corrosion resistance. The detailed results are shown in Table 1.

[0091] Table 1 Performance comparison of electrical contact components

[0092] type Peel strength N / mm Corrosion resistance test Example 1 Cu-Fe composite electrical contact assembly 55 No pitting after 24 hours Comparative Example Electrical contact assembly made of conventional copper-clad steel 40 8h The punched section begins to pit

[0093] As can be seen from Table 1, the electrical contact assembly in Example 1 is significantly superior to the electrical contact assembly in the comparative example in terms of peel strength and corrosion resistance. In addition, compared with the comparative example, the material composite interface in Example 2 is subjected to lateral force, which promotes the close bonding of the silver-copper composite interface, and the electrical contact assembly has a higher bonding strength; the electrical contact assembly in Example 2 has a smaller surface area of ​​the steel layer exposed to the air, and the corrosion resistance of the copper-steel composite electrical contact assembly is also better than that of the comparative example. The above-mentioned embodiment method of the present invention prepares high-strength, rust-proof and corrosion-resistant copper-steel composite materials and electrical contact assemblies for low-voltage electrical appliances.

[0094] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various modifications or variations within the scope of the claims, which does not affect the essence of the present invention. The above preferred features can be used in any combination without conflicting with each other.

Claims

1. A method for preparing a copper-steel composite material, characterized in that: include: Providing a copper base material, and performing a groove process on the upper surface of the copper base material to form a groove; The steel core material is embedded in the groove, and then the copper top material is covered on the steel core material and the copper base material, and then composite rolling is performed to obtain an integral material; heat treating the entire material; The heat-treated material is subjected to multiple cold rolling-annealing steps to obtain a copper-steel composite material strip; The copper-steel composite material strip is processed into strips to obtain a coated copper-steel composite material.

2. The method for preparing the copper-steel composite material according to claim 1, characterized in that: The upper surface of the copper base material is grooved to form a groove, wherein the groove is a long strip-shaped through groove running through the length direction of the copper base material, or a plurality of rectangular pits along the length direction of the copper base material.

3. The method for preparing the copper-steel composite material according to claim 1, characterized in that: The steel core material is placed in the groove, wherein: The width of the steel core material is 0.01 mm to 0.1 mm greater than the width of the groove; the height of the steel core material is 0.05 mm to 0.2 mm greater than the depth of the groove.

4. The method for preparing the copper-steel composite material according to claim 1, characterized in that: The method of covering the copper top material on the steel core material and the copper base material and then performing composite rolling comprises: Covering the steel core material and the copper base material with a copper top material to form a first composite material; The first composite material is placed in the positioning groove of the special-shaped rolling roller group, and is cold-compounded with a 30% to 70% deformation reduction using a special-shaped rolling mill at room temperature and in an atmospheric environment.

5. The method for preparing the copper-steel composite material according to claim 1, characterized in that: The method of covering the copper top material on the steel core material and the copper base material and then performing composite rolling comprises: Covering the steel core material and the copper base material with a copper top material, and reinforcing and welding the two ends of the copper base material and the copper top material to form a second composite material; The second composite material is placed in the positioning groove of the special-shaped roller group, and then hot-rolled composite rolling is performed with a special-shaped roller machine under a protective atmosphere or a vacuum atmosphere with a deformation reduction of 30% to 70%.

6. The method for preparing the copper-steel composite material according to claim 4 or 5, characterized in that: The upper roller and the lower roller of the special-shaped roller group are respectively provided with positioning grooves, and the width of the positioning grooves matches the width of the first composite material or the second composite material, so that the first composite material or the second composite material does not expand laterally during rolling, and the composite interface is subjected to lateral force, thereby promoting close bonding of the copper-steel composite interface.

7. The method for preparing the copper-steel composite material according to claim 1, characterized in that: The whole material is subjected to heat treatment, comprising: placing the whole material in a continuous annealing furnace, introducing reducing gas, and conducting heat treatment; wherein the heat treatment temperature is 300° C. to 900° C., and the strip pulling speed is 0.1 m / min to 10 m / min.

8. The method for preparing the copper-steel composite material according to claim 1, characterized in that: The heat-treated material is subjected to multiple cold rolling-annealing processes, wherein: the deformation amount of each cold rolling process is 10% to 30%; the annealing temperature is 300° C. to 800° C., the annealing time is 0.1h to 10h, and the annealing atmosphere is a protective atmosphere.

9. A copper-steel composite material, characterized in that: The copper-steel composite material is prepared by the preparation method of any one of claims 1 to 8, wherein the copper-steel composite material comprises a copper base material, a steel core material and a copper top material, wherein a groove is provided on one side of the copper base material, the shape of the steel core material matches the groove, the steel core material is embedded in the groove, and the copper top material covers the steel core material and the upper surface of the groove; the copper base material, the steel core material and the copper top material are composited into one, the four side walls of the copper-steel composite material are coated with copper material, and the middle core is steel material.

10. An electrical contact assembly, characterized in that: It comprises an electric contact and a support member, wherein the support member is made of the copper-steel composite material according to claim 9, and the electric contact is arranged on a surface of the support member.

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