Electric contact material and preparation method thereof, preparation method of electric contact material weldment and electric appliance element

Abstract

The embodiment of the invention discloses an electric contact material and a preparation method thereof, a preparation method of an electric contact material welding part and an electric appliance element, the electric contact material comprises a first material layer, an interface layer and a second material layer which are sequentially stacked, the first material layer is made of metal silver, and the second material layer is made of metal silver. The material of the second material layer comprises a graphene-copper composite material, and the interface layer comprises metal silver and the graphene-copper composite material which are mechanically engaged, or the interface layer comprises the metal silver and the graphene-copper composite material which are mechanically engaged and silver-copper alloy which is distributed in a dotted manner; wherein the graphene copper composite material comprises graphene and copper or a copper alloy, and the graphene is coated on the surface of the copper or the surface of the copper alloy. According to the application, the copper or the copper alloy is coated with the graphene, so that the dispersion degree of the graphene can be enhanced, and meanwhile, the generation amount of the silver-copper alloy is reduced, so that the electric contact material is not easy to generate fusion welding failure when being used to an interface.

Description

Technical Field

[0001] This application relates to the field of circuit breaker technology, specifically to an electrical contact material and its preparation method, a method for preparing welded electrical contact material components, and electrical components. Background Technology

[0002] Silver tungsten carbide graphite (AgWCC) has become the mainstream contact material for static contacts in circuit breakers due to its excellent oxidation resistance, weldability, corrosion resistance, relatively stable contact resistance, and reliable switching capacity. However, because silver is the main component of AgWCC, the cost of the contacts remains high. Furthermore, the processing of AgWCC requires silver plating on the welding surface to improve weldability, which is a complex process and carries the risk of delamination. Therefore, reducing the silver content in AgWCC, optimizing the processing technology, and improving its weldability are the key research directions for contact material development. Copper-based alloys possess electrical properties similar to silver-based materials and are currently considered ideal silver-saving composite materials.

[0003] Silver-tungsten-copper alloy electrical contact materials can replace AgWCC as contact materials, but interface treatment remains a major challenge. Related technologies employ a combination of a first additive, a second additive, diamond, and sandblasting to enhance the interfacial bonding strength between silver and copper; or they enhance the interfacial bonding strength by sandblasting, hot rolling, and diffusion annealing the silver-copper sheets. However, both methods carry a significant risk of interface failure during use. Summary of the Invention

[0004] This application provides an electrical contact material and its preparation method, a method for preparing welded parts of the electrical contact material, and an electrical component, which can improve the problem of interface failure.

[0005] This application provides an electrical contact material, comprising a first material layer, an interface layer, and a second material layer stacked sequentially. The material of the first material layer includes metallic silver, and the material of the second material layer includes a graphene-copper composite material. The interface layer includes mechanically interlocked metallic silver and graphene-copper composite material, or the interface layer includes mechanically interlocked metallic silver and graphene-copper composite material and a silver-copper alloy distributed in a dotted pattern. The graphene-copper composite material comprises graphene and copper or copper alloy, wherein the graphene is coated on the surface of the copper or the surface of the copper alloy.

[0006] Optionally, in some embodiments of this application, in the second material layer, at least 98% of the surface of the copper or copper alloy is covered by the graphene; and / or The copper alloy also contains rare earth elements.

[0007] Optionally, in some embodiments of this application, the material of the first material layer further includes graphene; and / or The material of the first material layer also includes tungsten carbide; and / or The material of the first material layer also includes one or more of rhenium, graphite, nickel, tungsten, and rare earth elements.

[0008] Optionally, in some embodiments of this application, the first material layer further includes rhenium, wherein the mass content of rhenium in the first material layer is 0.1%-6%; and / or The first material layer further includes graphite, wherein the graphite content in the first material layer is 0.15%-4% by mass; and / or The first material layer further includes nickel, wherein the nickel content in the first material layer is 0.5%-2% by mass; and / or The first material layer also includes tungsten, wherein the tungsten content in the first material layer is 1%-3% by mass; and / or The material of the first material layer also includes one or more rare earth elements, and the total mass content of the rare earth elements in the first material layer is 0.05%-1%.

[0009] Optionally, in some embodiments of this application, the material of the second material layer may further include one or more of tellurium, titanium carbide, tantalum carbide, diamond, rhenium, and rare earth elements.

[0010] Optionally, in some embodiments of this application, the material of the second material layer further includes tellurium, wherein the tellurium content in the second material layer is 0.5%-1% by mass; and / or The second material layer further includes titanium carbide, wherein the titanium carbide content in the second material layer is 0.1%-2% by mass; and / or The second material layer further includes tantalum carbide, wherein the tantalum carbide content in the second material layer is 0.1%-0.15% by mass; and / or The second material layer further includes diamond, wherein the diamond content in the second material layer is 0.1%-2% by mass; and / or The second material layer further includes rhenium, wherein the rhenium content in the second material layer is 0.1%-6% by mass; and / or The material of the second material layer also includes one or more rare earth elements, and the mass content of the rare earth elements in the second material layer is 0.05%-2%.

[0011] Accordingly, this application also provides a method for preparing an electrical contact material, comprising: The materials of the first material layer and the second material layer are stacked and then hot-pressed and sintered to form the first material layer and the second material layer, and an interface layer is formed between the first material layer and the second material layer. Wherein, the material of the first material layer includes metallic silver, the material of the second material layer includes graphene copper composite material, the interface layer includes mechanically interlocked metallic silver and graphene copper composite material, or, the interface layer includes mechanically interlocked metallic silver and graphene copper composite material and silver-copper alloy distributed in a dotted pattern, wherein, the graphene copper composite material includes graphene and copper or copper alloy, and the graphene is coated on the surface of the copper or the surface of the copper alloy; The hot pressing sintering temperature is below the melting point of silver.

[0012] Optionally, in some embodiments of this application, the hot-pressing sintering temperature is 550℃-800℃, and the hot-pressing sintering pressure is 60MPa-120MPa; and / or The hot pressing sintering is carried out in a mixed flow atmosphere of hydrogen and argon.

[0013] Optionally, in some embodiments of this application, a preparation step of graphene-copper composite material is also included, the step comprising: Copper particles or copper alloy particles are heated to a first temperature, and then a mixture of methane, hydrogen and oxygen is introduced to perform chemical vapor deposition. After chemical vapor deposition, the temperature is lowered, and a mixture of argon, hydrogen and methane is introduced during the cooling process to obtain copper particles or copper alloy particles with graphene coated on the surface. Wherein, the first temperature is 900℃-1050℃; and / or The temperature for chemical vapor deposition is 900℃-1050℃.

[0014] In addition, this application also provides an electrical contact material weldment, comprising: a welding sheet and the above-mentioned electrical contact material or an electrical contact material prepared by the above-mentioned method for preparing electrical contact material, wherein the second material layer is welded to the welding sheet.

[0015] Accordingly, this application also provides a method for preparing an electrical contact material welded component, comprising: The above-mentioned electrical contact material or the electrical contact material prepared by the above-mentioned method and the solder sheet are stacked together, with the second material layer facing the solder sheet. The electrical contact material and the solder sheet are pressed together and then furnace brazed to weld the second material layer to the solder sheet, thereby obtaining an electrical contact material welded part.

[0016] Optionally, in some embodiments of this application, the furnace brazing temperature is 650℃-700℃, and the furnace brazing holding time is 10min-20min; and / or The furnace brazing is performed in an inert gas atmosphere.

[0017] In addition, this application also provides an electrical component, including an electrical contact material welded component prepared by the above-described method.

[0018] This application achieves at least partial physical isolation between copper and silver by coating copper or copper alloys with graphene in the interface layer. At the same time, a low-temperature hot-pressing sintering process is used to reduce the sintering temperature, which causes the silver and copper in the first and second material layers to diffuse in a directional manner, forming a mechanically interlocked metallic silver and graphene copper composite material, or a mechanically interlocked metallic silver and graphene copper composite material, or a silver-copper alloy with a dotted distribution. This enhances the bonding strength of the interface and reduces the amount of silver-copper alloy formed, making it less likely for the electrical contact material to weld at the interface when used, thus solving the problem of silver-copper interface failure in silver-copper composite materials. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the structure of the electrical contact material provided in the embodiments of this application; Figure 2 This is a schematic diagram of the structure of the welded electrical contact material provided in the embodiments of this application; Figure 3 This is a process diagram for preparing welded electrical contact materials according to an embodiment of this application.

[0021] Explanation of reference numerals in the attached drawings: 1-First material layer; 2-Interface layer; 3-Second material layer; 4-Weld sheet; 5-Support component; 6-Ceramic pressure head. Detailed Implementation

[0022] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0023] In related technologies, the interfacial bonding strength between silver and copper is enhanced by using a mixture of a first additive, a second additive, diamond, and sandblasting; or by sandblasting, hot rolling, and diffusion annealing of silver-copper sheets. However, neither of these methods considers that the direct bonding of silver and copper will generate a large amount of low-melting-point, highly weldable silver-copper alloy at the composite interface during processing and welding. This significantly increases the risk of interface failure during use, and the copper layer only serves a supporting role, not contributing to actual application.

[0024] This application provides an electrical contact material and its preparation method, a method for preparing welded parts of the electrical contact material, and an electrical component. These are described in detail below. It should be noted that the order of description of the following embodiments is not intended to limit the preferred order of the embodiments. Furthermore, in the description of this application, the term "comprising" means "including but not limited to". The terms first, second, third, etc., are used merely as illustrative and do not impose numerical requirements or establish an order. Various embodiments of the present invention may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a rigid limitation on the scope of the invention; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Additionally, whenever a numerical range is indicated herein, it means including any referenced number (fraction or integer) within the indicated range.

[0025] Please see Figure 1 This application provides an electrical contact material comprising a first material layer 1, an interface layer 2, and a second material layer 3 stacked sequentially. The material of the first material layer 1 includes metallic silver, and the material of the second material layer 3 includes a graphene-copper composite material. The interface layer 2 includes mechanically interlocked metallic silver and graphene-copper composite material, or the interface layer 2 includes mechanically interlocked metallic silver and graphene-copper composite material and silver-copper alloy distributed in a dotted pattern. The graphene-copper composite material comprises graphene and copper or copper alloy, wherein the graphene is coated on the surface of the copper or the surface of the copper alloy.

[0026] In this application, by coating copper or copper alloys with graphene, at least partial physical isolation between copper and silver can be achieved in the interface layer 2 through graphene. This allows the silver and copper in the first material layer 1 and the second material layer 3 to diffuse in a directional manner, forming a mechanically interlocked metallic silver and graphene copper composite material, or a mechanically interlocked metallic silver and graphene copper composite material, or a silver-copper alloy distributed in a dotted pattern. This enhances the bonding strength of the interface while reducing the amount of silver-copper alloy formed, making it less prone to welding when the electrical contact material is used at the interface. This solves the problem of silver-copper interface failure in silver-copper composite materials, saving 40%-50% of silver usage while ensuring safety and reliability. In this material, the first material layer 1 is the working layer, and the second material layer 3 is both the working layer and the welding layer. Furthermore, by coating copper with graphene, the dispersibility of graphene in the electrical contact material can be improved, resulting in a more uniform and consistent structure of the formed electrical contact material.

[0027] It is understandable that the copper or copper alloy in the graphene-copper composite material can be completely or partially covered by graphene, and the surface of the copper or copper alloy can be fully or partially covered by graphene.

[0028] Optionally, in some embodiments of this application, at least 98% of the surface of the copper or copper alloy in the second material layer 3 is covered by the graphene. This ensures the bonding strength at the interface between the first material layer 1 and the second material layer 3, while controlling the amount of silver-copper alloy formed, making it less prone to welding when the electrical contact material is used at the interface.

[0029] Optionally, in some embodiments of this application, the material of the first material layer 1 may further include graphene.

[0030] It is understandable that by adding graphene to the first material layer 1, graphene can act as an additive to resist welding. Through the efficient heat dissipation and high conductivity of graphene, the contact resistance, temperature rise during use, and interface structure can be reduced, thereby improving the material's resistance to welding, resistance to arc erosion, and wear resistance.

[0031] Optionally, in some embodiments of this application, the material of the first material layer 1 may further include tungsten carbide.

[0032] Understandably, tungsten carbide can serve as an ablation-resistant phase in electrical contact materials, reducing localized melting, evaporation, and wear caused by electric arcs, thereby extending the service life of the contact components.

[0033] Optionally, in some embodiments of this application, the number of graphene layers on the surface of the copper or copper alloy in the graphene-copper composite material is 3-10 layers, for example, 3, 4, 5, 6, 7, 8, 9, or 10 layers.

[0034] Optionally, in some embodiments of this application, the copper alloy further includes rare earth elements (RE). Thus, rare earth elements in electrical contact materials can play a role in purifying and removing impurities, refining grain size, improving high-temperature mechanical properties and hot working properties, and enhancing corrosion resistance and electrical conductivity.

[0035] Optionally, in some embodiments of this application, the rare earth element includes one or more of yttrium, lanthanum, cerium, neodymium, and gadolinium.

[0036] Optionally, in some embodiments of this application, the material of the first material layer 1 may further include one or more of rhenium, graphite, nickel, tungsten, and rare earth elements (RE).

[0037] It is understandable that by adding rhenium to the first material layer 1, the ablation resistance and creep resistance of the first material layer 1 can be improved, and its contact resistance during use can be reduced; by adding graphite to the first material layer 1, the welding tendency of the first material layer 1 can be reduced; by adding nickel to the first material layer 1, the mechanical strength, wear resistance and arc resistance of the first material layer 1 can be improved; by adding rare earth elements (RE) to the first material layer 1, it can play a role in purifying and removing impurities, refining grains, improving high-temperature mechanical properties and hot working properties, and improving the corrosion resistance and conductivity of the material.

[0038] Optionally, in some embodiments of this application, the rare earth element includes one or more of yttrium, lanthanum, cerium, neodymium, and gadolinium.

[0039] Optionally, in some embodiments of this application, the material of the first material layer 1 further includes rhenium, and the mass content of rhenium in the first material layer 1 is 0.1%-6%, for example, it can be 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, etc.

[0040] Optionally, in some embodiments of this application, the material of the first material layer 1 further includes graphite, and the mass content of graphite in the first material layer 1 is 0.15%-4%, for example, it can be 0.15%, 0.5%, 0.75%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, etc.

[0041] Optionally, in some embodiments of this application, the material of the first material layer 1 further includes nickel, and the mass content of nickel in the first material layer 1 is 0.5%-2%, for example, it can be 0.5%, 0.75%, 1%, 1.25%, 1.5%, 1.75%, 2%, etc.

[0042] Optionally, in some embodiments of this application, the material of the first material layer 1 further includes tungsten, and the mass content of the tungsten in the first material layer 1 is 1%-3%, for example, it can be 1%, 1.25%, 1.5%, 1.75%, 2%, 2.25%, 2.5%, 2.75%, 3%, etc.

[0043] Optionally, in some embodiments of this application, the material of the first material layer 1 further includes one or more rare earth elements (RE), and the total mass content of the rare earth elements (RE) in the first material layer 1 is 0.05%-1%, for example, it can be 0.05%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, etc.

[0044] Optionally, in some embodiments of this application, the material of the second material layer 3 may further include one or more of tellurium, titanium carbide, tantalum carbide, diamond, rhenium, and rare earth elements (RE).

[0045] It is understandable that adding tellurium to the second material layer 3 can reduce its tendency to weld; adding titanium carbide, tantalum carbide, or diamond to the second material layer 3 can further reduce its tendency to weld and improve its resistance to burn-off and oxidation; adding rhenium can improve its resistance to ablation and creep, and reduce its contact resistance during use; adding rare earth elements (RE) to the second material layer 3 can purify and remove impurities, refine grains, improve high-temperature mechanical properties and hot working properties, and enhance the material's corrosion resistance, oxidation resistance, and electrical conductivity. Simultaneously, the second material layer 3 can serve as both a working layer and a welding layer, thereby reducing the need for conventional silver plating processes for welding in conventional products.

[0046] Optionally, in some embodiments of this application, the rare earth element includes one or more of yttrium, lanthanum, cerium, neodymium, and gadolinium.

[0047] Optionally, in some embodiments of this application, the material of the second material layer 3 further includes tellurium, and the mass content of tellurium in the second material layer 3 is 0.5%-1%, for example, it can be 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, etc.

[0048] Optionally, in some embodiments of this application, the material of the second material layer 3 further includes titanium carbide, and the mass content of titanium carbide in the second material layer 3 is 0.1%-2%, for example, it can be 0.1%, 0.3%, 0.5%, 0.7%, 1%, 1.3%, 1.5%, 1.7%, 2%, etc.

[0049] Optionally, in some embodiments of this application, the material of the second material layer 3 further includes tantalum carbide, and the mass content of tantalum carbide in the second material layer 3 is 0.1%-0.15%, for example, it can be 0.1%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, etc.

[0050] Optionally, in some embodiments of this application, the material of the second material layer 3 further includes diamond, and the mass content of diamond in the second material layer 3 is 0.1%-2%, for example, it can be 0.1%, 0.3%, 0.5%, 0.7%, 1%, 1.3%, 1.5%, 1.7%, 2%, etc.

[0051] Optionally, in some embodiments of this application, the material of the second material layer 3 further includes rhenium, and the mass content of rhenium in the second material layer 3 is 0.1%-6%, for example, it can be 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, etc.

[0052] Optionally, in some embodiments of this application, the material of the second material layer 3 further includes one or more rare earth elements (RE), and the mass content of the rare earth elements (RE) in the second material layer 3 is 0.05%-2%, for example, it can be 0.05%, 0.2%, 0.5%, 0.7%, 1%, 1.2%, 1.5%, 1.7%, 2%, etc.

[0053] Please see Figure 1 This application also provides a method for preparing an electrical contact material, comprising: The materials of the first material layer 1 and the second material layer 3 are stacked and then hot-pressed and sintered to form the first material layer 1 and the second material layer 3, and an interface layer 2 is formed between the first material layer 1 and the second material layer 3. Wherein, the material of the first material layer 1 includes metallic silver, the material of the second material layer 3 includes graphene copper composite material, the interface layer 2 includes mechanically interlocked metallic silver and graphene copper composite material, or the interface layer 2 includes mechanically interlocked metallic silver and graphene copper composite material and silver-copper alloy distributed in a dotted pattern, wherein the graphene copper composite material includes graphene and copper or copper alloy, and the graphene is coated on the surface of the copper or the surface of the copper alloy; The hot pressing sintering temperature is below the melting point of silver.

[0054] In this application, by employing a low-temperature hot-pressing sintering process, the interface layer 2 can be formed into a mechanically interlocked composite material of metallic silver and graphene copper, or a mechanically interlocked composite material of metallic silver and graphene copper, as well as a silver-copper alloy with a dotted distribution. This enhances the bonding strength of the interface while reducing the amount of silver-copper alloy formed, making it less prone to welding when the electrical contact material is used at the interface. This solves the problem of silver-copper interface failure in silver-copper composite materials, saving 40%-50% of silver usage while ensuring safety and reliability. In this material, the first material layer 1 is the working layer, and the second material layer 3 is both the working layer and the welding layer. Furthermore, coating copper with graphene improves the dispersion of graphene in the electrical contact material, resulting in a more uniform and consistent structure. The interface layer 2 does not need to be fabricated separately, simplifying the process and saving costs.

[0055] Understandably, since the hot pressing sintering temperature is lower than the melting point of silver and much lower than the melting point of copper, the amount of silver-copper alloy produced can be effectively controlled by the physical barrier effect of graphene. Optionally, in some embodiments of this application, before hot pressing and sintering, the process further includes: pre-pressing the materials of the first material layer 1 and the second material layer 3 that are stacked together.

[0056] Optionally, in some embodiments of this application, the hot pressing sintering temperature is 550℃-800℃, for example, 550℃, 600℃, 650℃, 700℃, 750℃, 800℃, etc., and the hot pressing sintering pressure is 60MPa-120MPa, for example, 60MPa, 70MPa, 80MPa, 90MPa, 100MPa, 110MPa, 120MPa, etc.

[0057] Optionally, in some embodiments of this application, the hot pressing sintering temperature is 550℃-700℃, for example, it can be 550℃, 570℃, 600℃, 620℃, 650℃, 670℃, 700℃, etc.

[0058] It is understandable that by controlling the temperature and pressure of hot pressing sintering, a mechanically interlocked silver-copper diffusion layer, or a mechanically interlocked silver-copper diffusion layer and a controllable discontinuous silver-copper alloy layer, can be formed between the first material layer 1 and the second material layer 3.

[0059] Optionally, in some embodiments of this application, the hot pressing sintering is carried out in a mixed flow atmosphere of hydrogen and argon. This reduces the probability of oxidation of the electrical contact material and improves process safety.

[0060] Optionally, in some embodiments of this application, a graphene-copper composite material preparation step is also included, the step comprising: Copper particles or copper alloy particles are heated to a first temperature, and then a mixture of methane, hydrogen, and oxygen is introduced to perform chemical vapor deposition. After chemical vapor deposition, the temperature is lowered, and a mixture of argon, hydrogen, and methane is introduced during the cooling process to obtain copper particles or copper alloy particles with graphene coated on the surface.

[0061] Optionally, in some embodiments of this application, the first temperature is 900℃-1050℃, for example, it can be 900℃, 920℃, 940℃, 960℃, 980℃, 1000℃, 1020℃, 1040℃, 1050℃, etc.

[0062] Optionally, in some embodiments of this application, the temperature of the chemical vapor deposition is 900℃-1050℃, for example, it can be 900℃, 920℃, 940℃, 960℃, 980℃, 1000℃, 1020℃, 1040℃, 1050℃, etc.

[0063] Please see Figure 2 This application embodiment also provides an electrical contact material weldment, including: the above-mentioned electrical contact material and the welding sheet 4, wherein the second material layer 3 is welded to the welding sheet 4.

[0064] Please see Figure 3 This application also provides a method for preparing an electrical contact material welded component, comprising: The above-mentioned electrical contact material and welding sheet 4 are stacked, with the second material layer 3 facing the welding sheet 4. The electrical contact material and welding sheet 4 are pressed together and then brazed in a furnace to weld the second material layer 3 to the welding sheet 4, thereby obtaining an electrical contact material welded part.

[0065] In this application, furnace brazing is used for welding connection, which requires a lower temperature. This makes it less likely for excessive silver-copper alloy to form in the interface layer 2 between the second material layer 3 and the first material layer 1, thereby reducing the probability of welding failure.

[0066] As an example, when manufacturing electrical contact material welded parts, the ceramic pressure head 6, electrical contact material, welding sheet 4 and support 5 can be placed one above the other in sequence and pressure can be applied before furnace brazing.

[0067] Optionally, in some embodiments of this application, the furnace brazing temperature is 650℃-700℃, for example, it can be 650℃, 660℃, 670℃, 680℃, 690℃, 700℃, etc., and the furnace brazing holding time is 10min-20min, for example, it can be 10min, 12min, 14min, 16min, 18min, 20min, etc.

[0068] Optionally, in some embodiments of this application, the furnace brazing is performed in an inert gas atmosphere.

[0069] This application also provides an electrical component, including the above-described electrical contact material weldment.

[0070] As an example, the electrical component in this application can be a circuit breaker.

[0071] Example 1 An electrical contact material and its preparation method, comprising: S1: Electrolytic copper powder is heated to 1000℃ under argon conditions, and then a mixture of methane, hydrogen and oxygen is introduced to carry out chemical vapor deposition. After the chemical vapor deposition process is completed, the temperature is lowered, and a mixture of argon, hydrogen and methane is introduced during the cooling process to obtain copper particles with graphene coated on the surface. S2: Copper particles coated with graphene are mixed evenly with RE, tantalum carbide and diamond in an acoustic resonance instrument to obtain copper-graphene composite powder. S3: Silver, graphene, tungsten carbide, rhenium, RE, and nickel powders are placed in an acoustic resonance instrument and mixed evenly to obtain silver-graphene composite powder; S4: Add copper graphene composite powder to the mold and vibrate it. Then add silver graphene composite powder and pre-press it. Then place it into a hot-press graphite mold and perform hot-press sintering in a hot-press sintering furnace. The sintering temperature is 750℃ and the pressure is 70MPa. After sintering, AgWCGr / CuGr composite electrical contact material is obtained.

[0072] A welded component made of electrical contact material and a method for preparing the same, comprising: The ceramic pressure head, AgWCGr / CuGr composite electrical contact material, welding sheet and support are placed one above the other in sequence and pressure is applied before furnace brazing. The furnace brazing temperature is 680℃ and the holding time is 10min. The furnace is in a nitrogen protective atmosphere. After welding, the AgWCGr / CuGr composite electrical contact material welded part is obtained.

[0073] Example 2 An electrical contact material and its preparation method, comprising: S1: Electrolytic copper powder is heated to 1050℃ under argon conditions, and then a mixture of methane, hydrogen and oxygen is introduced to carry out chemical vapor deposition. After the chemical vapor deposition process is completed, the temperature is lowered, and a mixture of argon, hydrogen and methane is introduced during the cooling process to obtain copper particles with graphene coated on the surface. S2: Copper particles coated with graphene are mixed with RE, tellurium, and titanium carbide in an acoustic resonance instrument to obtain copper-graphene composite powder. S3: Silver, graphene, tungsten carbide, rhenium, graphite, tungsten, and RE powder are placed in an acoustic resonance instrument and mixed evenly to obtain silver-graphene composite powder; S4: Add copper graphene composite powder to the mold and vibrate it, then add silver graphene composite powder and pre-press it, then put it into a hot-pressing graphite mold and perform hot-pressing sintering in a hot-pressing sintering furnace at a temperature of 780℃ and a pressure of 80MPa. After sintering, AgWCGr / CuGr composite electrical contact material is obtained.

[0074] A welded component made of electrical contact material and a method for preparing the same, comprising: The ceramic pressure head, AgWCGr / CuGr composite electrical contact material, welding sheet and support are placed one above the other in sequence and pressure is applied before furnace brazing. The furnace brazing temperature is 700℃ and the holding time is 10min. The furnace is in an inert gas protective atmosphere. After welding, the AgWCGr / CuGr composite electrical contact material welded part is obtained.

[0075] Example 3 An electrical contact material and its preparation method, comprising: S1: The copper-lanthanum alloy powder is heated to 1050°C under argon conditions, and then a mixture of methane, hydrogen and oxygen is introduced to carry out chemical vapor deposition. After the chemical vapor deposition process is completed, the temperature is lowered, and a mixture of argon, hydrogen and methane is introduced during the cooling process to obtain copper-lanthanum particles with graphene coated on the surface. S2: Copper lanthanum particles coated with graphene are mixed evenly with reinforcing materials tellurium, titanium carbide and diamond in an acoustic resonance instrument to obtain copper graphene composite powder. S3: Silver, graphene, tungsten carbide, rhenium (reinforcing material), RE, and nickel powder are mixed evenly in an acoustic resonance apparatus to obtain silver-graphene composite powder; S4: Add copper graphene composite powder to the mold and vibrate it. Then add silver graphene composite powder and pre-press it. Then place it into a hot-press graphite mold and perform hot-press sintering in a hot-press sintering furnace. The sintering temperature is 700℃ and the pressure is 90MPa. After sintering, AgWCGr / CuGr composite electrical contact material is obtained.

[0076] A welded component made of electrical contact material and a method for preparing the same, comprising: The ceramic pressure head, AgWCGr / CuGr composite electrical contact material, welding sheet and support are placed one above the other in sequence and pressure is applied before furnace brazing. The furnace brazing temperature is 680℃ and the holding time is 10min. The furnace is in an inert gas protective atmosphere. After welding, the AgWCGr / CuGr composite electrical contact material welded part is obtained.

[0077] Example 4 An electrical contact material and its preparation method, comprising: S1: Copper-cerium alloy powder is heated to 1050℃ under argon conditions, and then a mixture of methane, hydrogen and oxygen is introduced to carry out chemical vapor deposition. After the chemical vapor deposition process is completed, the temperature is lowered, and a mixture of argon, hydrogen and methane is introduced during the cooling process to obtain copper-cerium particles with graphene coated on the surface. S2: Copper-cerium particles coated with graphene are mixed evenly with tellurium, tantalum carbide and diamond in an acoustic resonance instrument to obtain copper-graphene composite powder. S3: Silver, graphene, tungsten carbide, rhenium, RE, graphite powder, and tungsten powder are mixed evenly in an acoustic resonance instrument to obtain silver-graphene composite powder; S4: Add copper graphene composite powder to the mold and vibrate it. Then add silver graphene composite powder and pre-press it. Then place it into a hot-press graphite mold and perform hot-press sintering in a hot-press sintering furnace. The sintering temperature is 700℃ and the pressure is 90MPa. After sintering, AgWCGr / CuGr composite electrical contact material is obtained.

[0078] A welded component made of electrical contact material and a method for preparing the same, comprising: The ceramic pressure head, AgWCGr / CuGr composite electrical contact material, welding sheet and support are placed one above the other in sequence and pressure is applied before furnace brazing. The furnace brazing temperature is 680℃ and the holding time is 10min. The furnace is in an inert gas protective atmosphere. After welding, the AgWCGr / CuGr composite electrical contact material welded part is obtained.

[0079] The electrical contact material weldment provided in this application embodiment should be designed so that it is not easy to undergo fusion welding when used at the interface in circuit breakers, and the first material layer is the working layer, and the second material layer is both the working layer and the welding layer.

[0080] The above provides a detailed description of an electrical contact material and its preparation method, a method for preparing welded electrical contact materials, and an electrical component provided in the embodiments of this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. An electrical contact material, characterized in that, It includes a first material layer, an interface layer, and a second material layer stacked in sequence. The material of the first material layer includes metallic silver, the material of the second material layer includes a graphene copper composite material, and the interface layer includes mechanically interlocked metallic silver and graphene copper composite material, or the interface layer includes mechanically interlocked metallic silver and graphene copper composite material and silver-copper alloy distributed in a dotted pattern. The graphene-copper composite material comprises graphene and copper or copper alloy, wherein the graphene is coated on the surface of the copper or the surface of the copper alloy.

2. The electrical contact material according to claim 1, characterized in that, In the second material layer, at least 98% of the surface of the copper or copper alloy is covered by the graphene; and / or The copper alloy contains rare earth elements.

3. The electrical contact material according to claim 1, characterized in that, The material of the first material layer also includes graphene; and / or The material of the first material layer also includes tungsten carbide; and / or The material of the first material layer also includes one or more of rhenium, graphite, nickel, tungsten, and rare earth elements.

4. The electrical contact material according to claim 3, characterized in that, The first material layer further includes rhenium, wherein the rhenium content in the first material layer is 0.1%-6% by mass; and / or The first material layer also includes graphite, and the mass content of graphite in the first material layer is 0.15%-4%; and / or The first material layer further includes nickel, wherein the nickel content in the first material layer is 0.5%-2% by mass; and / or The first material layer also includes tungsten, wherein the tungsten content in the first material layer is 1%-3% by mass; and / or The material of the first material layer also includes one or more rare earth elements, and the total mass content of the rare earth elements in the first material layer is 0.05%-1%.

5. The electrical contact material according to claim 1, characterized in that, The material of the second material layer also includes one or more of tellurium, titanium carbide, tantalum carbide, diamond, rhenium, and rare earth elements.

6. The electrical contact material according to claim 5, characterized in that, The second material layer further includes tellurium, wherein the tellurium content in the second material layer is 0.5%-1% by mass; and / or The second material layer further includes titanium carbide, wherein the titanium carbide content in the second material layer is 0.1%-2% by mass; and / or The second material layer further includes tantalum carbide, wherein the tantalum carbide content in the second material layer is 0.1%-0.15% by mass; and / or The second material layer further includes diamond, wherein the diamond content in the second material layer is 0.1%-2% by mass; and / or The second material layer further includes rhenium, wherein the rhenium content in the second material layer is 0.1%-6% by mass; and / or The material of the second material layer also includes one or more rare earth elements, and the mass content of the rare earth elements in the second material layer is 0.05%-2%.

7. A method for preparing an electrical contact material, characterized in that, include: The materials of the first material layer and the second material layer are stacked and then hot-pressed and sintered to form the first material layer and the second material layer, and an interface layer is formed between the first material layer and the second material layer. Wherein, the material of the first material layer includes metallic silver, the material of the second material layer includes graphene copper composite material, the interface layer includes mechanically interlocked metallic silver and graphene copper composite material, or, the interface layer includes mechanically interlocked metallic silver and graphene copper composite material and silver-copper alloy distributed in a dotted pattern, wherein, the graphene copper composite material includes graphene and copper or copper alloy, and the graphene is coated on the surface of the copper or the surface of the copper alloy; The hot pressing sintering temperature is below the melting point of silver.

8. The method for preparing the electrical contact material according to claim 7, characterized in that, The hot-pressing sintering temperature is 550℃-800℃, and the hot-pressing sintering pressure is 60MPa-120MPa; and / or The hot pressing sintering is carried out in a mixed flow atmosphere of hydrogen and argon.

9. The method for preparing the electrical contact material according to claim 7, characterized in that, It also includes a preparation step for graphene-copper composite materials, the step comprising: Copper particles or copper alloy particles are heated to a first temperature, and then a mixture of methane, hydrogen and oxygen is introduced to perform chemical vapor deposition. After chemical vapor deposition, the temperature is lowered, and a mixture of argon, hydrogen and methane is introduced during the cooling process to obtain copper particles or copper alloy particles with graphene coated on the surface. Wherein, the first temperature is 900℃-1050℃; and / or The temperature for chemical vapor deposition is 900℃-1050℃.

10. A method for preparing an electrical contact material welded component, characterized in that, include: An electrical contact material and a solder sheet prepared by the method of preparing an electrical contact material as described in any one of claims 1-6 or as described in claim 7 or 8 are stacked together, with the second material layer facing the solder sheet. The electrical contact material and the solder sheet are pressed together and then brazed in a furnace to weld the second material layer to the solder sheet, thereby obtaining a welded electrical contact material component.

11. An electrical component, characterized in that, This includes electrical contact material welded parts prepared by the method for preparing electrical contact material welded parts as described in claim 10.

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