Copper-chromium alloy, preparation method and copper-chromium alloy contact seat

Abstract

The invention discloses a copper-chromium alloy, a preparation method and a copper-chromium alloy contact seat, and the method comprises the following steps: smelting chromium, lanthanum and copper according to a set proportion to obtain a copper-chromium alloy melt; casting the copper-chromium alloy melt to obtain a copper-chromium alloy blank; forging the copper-chromium alloy blank to obtain a copper-chromium alloy bar; the copper-chromium alloy bar material is subjected to drawing, so that the drawn copper-chromium alloy bar material is obtained; and the drawn copper-chromium alloy bar is sawn into a set length, the sawn copper-chromium alloy bar is subjected to induction heating, the copper-chromium alloy bar subjected to induction heating is subjected to extrusion forming, and the copper-chromium alloy is obtained. According to the copper-chromium alloy, various properties including electric conductivity, tensile strength and the like of the copper-chromium alloy can be improved.

Description

Technical Field

[0001] The present application belongs to the technical field of electric power equipment manufacturing, and specifically relates to a copper-chromium alloy, a preparation method and a copper-chromium alloy contact seat. Background Art

[0002] The contact seat is a key component in high-voltage switchgear. The material used to make it must not only have high electrical and thermal conductivity, but also sufficient mechanical strength and hardness to ensure stable operation under high voltage and high current conditions. Commonly used copper-chromium alloys (such as Cu-Cr, Cu-Ni-Si and Cu-Fe-P series) are widely used due to their excellent comprehensive performance, but traditional materials such as aluminum alloys have poor electrical conductivity and pure copper has insufficient strength. Although the existing casting process is low-cost, it is prone to defects. For example, the prepared contact seat is prone to defects such as pores and inclusions. Therefore, it is necessary to develop a new material and optimize the production process to improve the performance of the contact seat to meet the application requirements of higher voltage and larger current. Summary of the invention

[0003] The main purpose of the present application is to provide a copper-chromium alloy, a preparation method and a copper-chromium alloy contact seat, and the present application can improve the mechanical properties of the copper-chromium alloy.

[0004] To achieve the above objectives, this application provides the following technical solutions:

[0005] A copper-chromium alloy, the components of the copper-chromium alloy and the mass percentage of each component are: chromium: 0.2wt%-0.5wt%, lanthanum: 0.05wt%-0.1wt%, copper: balance.

[0006] The present application also provides a method for preparing a copper-chromium alloy, the method comprising: smelting chromium, lanthanum and copper in a set ratio to obtain a copper-chromium alloy melt; casting the copper-chromium alloy melt to obtain a copper-chromium alloy blank; forging the copper-chromium alloy blank to obtain a copper-chromium alloy bar; drawing the copper-chromium alloy bar to obtain a drawn copper-chromium alloy bar;

[0007] The drawn copper-chromium alloy bar is sawn into a set length, the sawn copper-chromium alloy bar is induction heated, and the induction heated copper-chromium alloy bar is extruded to obtain the copper-chromium alloy.

[0008] Optionally, chromium, lanthanum and copper are smelted at a temperature of 1100°C to 1250°C.

[0009] Optionally, forging the copper-chromium alloy blank includes: preheating the copper-chromium alloy blank; performing preliminary forging on the preheated copper-chromium alloy blank; performing finish forging on the copper-chromium alloy blank after the preliminary forging; and cooling the copper-chromium alloy blank after the finish forging.

[0010] Optionally, the copper-chromium alloy bar is drawn using a multi-stage progressive drawing method.

[0011] Optionally, the preparation method further comprises: performing a solid solution treatment on the copper-chromium alloy.

[0012] Optionally, the preparation method further comprises: performing aging treatment on the copper-chromium alloy after the solution treatment.

[0013] The present application also provides a copper-chromium alloy contact seat, which is made of the copper-chromium alloy as described above, and comprises: a contact seat body, a connecting block is arranged at one side edge of the contact seat body, and a first wing plate and a second wing plate are symmetrically arranged on both sides of the connecting block, and the first wing plate and the second wing plate both include a fixed side and an extended side, wherein the first wing plate and the second wing plate are connected to the connecting block through the fixed side, and the extended sides of the first wing plate and the second wing plate extend along the edge of the contact seat body to the side opposite to the connecting block, and the first wing plate, the second wing plate and the connecting block form a fixed structure.

[0014] Optionally, a connection hole is provided at a central position of the contact seat body, and the contact seat body is connected to the copper-chromium alloy contact through the connection hole.

[0015] Optionally, heat dissipation holes are arranged around the connection hole.

[0016] This application can bring the following technical effects: By implementing a series of preparation processes, this application can not only ensure that the copper-chromium alloy has excellent conductivity, hardness and tensile strength, but also greatly improve its toughness and corrosion resistance, providing a more reliable and high-quality material selection for the manufacture of high-performance power equipment, and meeting the strict requirements of high voltage and high current applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic flow chart of a method for preparing a copper-chromium alloy provided in one embodiment of the present application;

[0018] Figure 2 It is a structural schematic diagram of a copper-chromium alloy contact seat provided in one embodiment of the present application.

[0019] The following are the descriptions of the reference numerals:

[0020] 1. Contact seat body; 2-1. First wing plate; 2-2. Second wing plate; 3. Mounting plate; 4. Connecting block; 5. Connecting part; 6. Connecting hole; 7. Heat dissipation hole; 8. Mounting hole. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0023] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0024] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the meaning of "and / or" appearing in the full text includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme that satisfies both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in the field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0025] In an exemplary embodiment, the present application provides a copper-chromium alloy, wherein the components of the copper-chromium alloy and the mass percentage of each component are: 0.2wt% to 0.5wt% of chromium, 0.05wt% to 0.1wt% of lanthanum, and the balance of copper.

[0026] In this embodiment, chromium is an effective strengthening element that can significantly improve the strength and hardness of the copper-based alloy. An appropriate amount of chromium can promote the formation of precipitation hardening phases, thereby improving the mechanical properties of the material. However, too much chromium will reduce the electrical conductivity of copper. It is found through experiments that when the chromium content is between 0.2wt% and 0.5wt%, the copper-chromium alloy can obtain the desired strength and hardness without significantly sacrificing conductivity. Lanthanum has the effect of refining grains, which helps to improve the microstructure of the material, thereby improving its mechanical properties and dimensional stability. In addition, lanthanum can also effectively remove impurities in the melt, especially harmful elements such as oxygen and sulfur, reduce the formation of pores and inclusions, and improve the density of the material. It is found through experiments that a lanthanum content of 0.05wt% to 0.1wt% is sufficient to produce the above effects without introducing unnecessary complexity or negative effects. Further, the present application systematically studies the effects of different chromium and lanthanum contents on the properties of copper-chromium alloys through a series of laboratory experiments, including smelting, casting, heat treatment and mechanical property testing. Statistical methods and response surface analysis techniques were used to evaluate the comprehensive performance indicators of various component combinations, such as tensile strength, hardness, conductivity, etc., and the corresponding mathematical models were established. Finally, based on experimental data and model predictions, the following optimal ratio was determined: chromium: 0.35wt%, lanthanum: 0.075wt%, copper: balance. The copper-chromium alloy at this ratio can show the highest tensile strength (about 460MPa), hardness (HB 115) and good conductivity (>92% IACS), while maintaining excellent dimensional stability and surface quality.

[0027] It should be noted that the reason why lanthanum (La) is used as an additive element in the copper-chromium alloy in the present application is mainly because it has the following characteristics:

[0028] Characteristic 1: Lanthanum can effectively refine the grains of the copper-chromium alloy, help improve the microstructure of the copper-chromium alloy, and further improve its mechanical properties and dimensional stability.

[0029] Feature 2: Lanthanum can effectively remove impurities in the melt, especially harmful elements such as oxygen and sulfur, reduce the formation of pores and inclusions, and improve the density of the copper-chromium alloy.

[0030] Property 3: Lanthanum can enhance the strength and hardness of the copper-chromium alloy through a precipitation hardening mechanism without significantly sacrificing electrical conductivity.

[0031] Characteristic 4: The presence of lanthanum can improve the response of the copper-chromium alloy to heat treatment, such as the effect of solution treatment and aging treatment, thereby further improving the performance of the copper-chromium alloy.

[0032] In contrast, some other common rare elements are not as suitable for copper-chromium alloys as lanthanum. For example, yttrium (Y) is also an effective grain refiner and can improve the corrosion resistance and high temperature performance of the copper-chromium alloy. However, in some cases, yttrium can lead to increased processing difficulty or increased costs. Cerium (Ce) is a rare earth element like lanthanum and can also play a role in purifying the melt, but it has a greater impact on the environment and can cause increased brittleness in the copper-chromium alloy. Titanium (Ti) is a strong carbide-forming element that can significantly improve the hardness and wear resistance of the copper-chromium alloy, but studies have shown that it will reduce the electrical conductivity of the copper-chromium alloy to a certain extent.

[0033] In summary, lanthanum is selected as an additive element based on its comprehensive advantages in grain refinement, melt purification, strengthening effect and heat treatment response, which are crucial for optimizing the properties of the copper-chromium alloy.

[0034] Figure 1 FIG. 1 is a schematic flow chart of a method for preparing a copper-chromium alloy according to an embodiment of the present application, such as Figure 1 As shown, the preparation method comprises the following steps:

[0035] S1: smelting chromium, lanthanum (La) and copper in a non-vacuum medium frequency induction furnace at a temperature of 1100° C. to obtain a copper-chromium alloy melt, wherein the mass percentage of chromium is 0.2wt% to 0.5wt%, the mass percentage of lanthanum (La) is 0.05wt% to 0.1wt%, and the balance is copper;

[0036] S2: casting the copper-chromium alloy melt to obtain a copper-chromium alloy blank;

[0037] Casting the copper-chromium alloy melt specifically includes the following steps: using a crystallizer to pour the copper-chromium alloy melt into a chute, and starting an atmosphere protection measure (such as introducing argon to prevent the copper-chromium alloy melt from oxidation); when the copper-chromium alloy melt enters the crystallizer to a height of one-third of its volume, casting begins, the initial casting speed is 50 mm / min, and electromagnetic stirring is started at the same time (the stirring frequency is set to 1 Hz, and the current intensity is set to 30A). This initial setting helps the copper-chromium alloy melt to smoothly fill the bottom area of ​​the crystallizer and reduce the risk of turbulence and bubble formation. When the copper-chromium alloy melt is filled to 75% to 85% of the crystallizer volume, the stirring frequency is adjusted to 3 Hz, the current intensity is adjusted to 60A, and the casting speed is gradually increased to 100 mm / min. This step enhances the stirring intensity, further refines the grain structure in the copper-chromium alloy melt, and makes each component more evenly dispersed in the entire volume, reducing the possibility of component segregation. In addition, during this process, mechanical vibration is applied at 30 times / minute to help discharge the tiny bubbles that may exist in the copper-chromium alloy melt, prevent the formation of pores and inclusions, and improve the density and mechanical properties of the copper-chromium alloy. After the above steps are completed, a copper-chromium alloy blank can be obtained.

[0038] It should be noted that the crystallizer needs to be preheated before casting. If the crystallizer is not preheated, a huge temperature difference will occur between the two when it comes into contact with the high-temperature copper-chromium alloy melt. This drastic temperature change will cause the surface of the copper-chromium alloy melt to cool rapidly, forming a very thin and hardened surface layer, while the interior is still liquid or semi-solid. This situation will cause a significant temperature gradient and cause an uneven internal structure of the material. By preheating the crystallizer so that its temperature is close to that of the copper-chromium alloy melt, the temperature difference between the two can be greatly reduced, so that the melt can cool more slowly when it contacts the wall of the crystallizer, which helps to form a more uniform solidification interface and avoid composition segregation or microstructural abnormalities caused by rapid cooling.

[0039] S3: forging the copper-chromium alloy blank to obtain a copper-chromium alloy bar;

[0040] In this step, the copper-chromium alloy blank is forged, which specifically includes the following steps:

[0041] First, the copper-chromium alloy blank is preheated to ensure that the copper-chromium alloy blank reaches an appropriate temperature (usually 800° C. to 1050° C.) before forging, so as to increase the ductility of the copper-chromium alloy blank and reduce the internal stress during the forging process.

[0042] Secondly, the preheated copper-chromium alloy blank is subjected to preliminary forging, that is, a large-tonnage forging hammer or hydraulic press is used to perform preliminary strikes on the preheated copper-chromium alloy blank, so that the copper-chromium alloy blank is quickly deformed into a rough rod-like shape. The main goal of this stage is to break the coarse grains in the cast structure to provide a basis for subsequent finishing. In this process, upsetting (shortening the length and increasing the diameter) and stretching (stretching while reducing the diameter) operations are performed alternately to gradually adjust the geometric shape of the blank until it is close to the size specification of the final bar. It should be noted that appropriate cooling should be performed after each forging to avoid overheating and excessive softening of the material or cracks.

[0043] Secondly, the copper-chromium alloy blank after preliminary forging is subjected to finishing forging, that is, the semi-finished product after preliminary forging is subjected to final forming processing using a precisely designed die to achieve the specified dimensional accuracy and surface finish. This step usually requires high control accuracy to ensure the quality consistency of the product. During the entire forging process, the force and degree of deformation of each blow need to be strictly controlled to avoid local stress concentration or uneven deformation, thereby ensuring the consistency and integrity of the internal structure of the copper-chromium alloy blank.

[0044] Finally, after completing the forging process, the copper-chromium alloy rod material obtained needs to be cooled, specifically by burying it in a sand pile or slowly cooling it in a furnace, so as to reduce residual stress and improve the stability and mechanical properties of the copper-chromium alloy rod material.

[0045] S4: drawing the copper-chromium alloy bar to obtain a drawn copper-chromium alloy bar;

[0046] In this step, the present application designs a multi-stage progressive drawing method. First, before drawing the copper-chromium alloy bar, it is necessary to heat it to an appropriate temperature (e.g., 400°C to 500°C) to improve the ductility of the copper-chromium alloy bar and reduce the internal stress during the drawing process, which helps to prevent cracks or other defects in the copper-chromium alloy bar during the drawing process. Secondly, the first drawing is performed using a die with the largest diameter so that the copper-chromium alloy bar is initially formed. During this process, the drawing speed is slow so that the copper-chromium alloy bar can fully adapt to the new shape. Finally, a smaller diameter die is gradually replaced (the die aperture of each stage is slightly smaller than that of the previous stage, and each time it is reduced by about 5% to 10%) for subsequent stages of drawing operations. It should be noted that as the die diameter gradually decreases, the drawing speed should be appropriately increased, and the copper-chromium alloy bar can achieve the final required dimensional accuracy and surface finish through the gradually reduced die and appropriate drawing speed adjustment.

[0047] The present application adopts a multi-stage progressive drawing method, which can gradually refine the grains inside the copper-chromium alloy bar, thereby helping to improve the mechanical strength, hardness and wear resistance of the copper-chromium alloy. In addition, during the multi-stage drawing process, as the die aperture gradually decreases, the final size of the copper-chromium alloy bar can be more accurately controlled and a better surface finish can be obtained.

[0048] S5: sawing the drawn copper-chromium alloy rod into a set length, and induction heating the sawed copper-chromium alloy rod at a temperature of 950° C. for 10 minutes by a resistance furnace, and then extruding the heated copper-chromium alloy rod using a Hough die to obtain a copper-chromium alloy.

[0049] In another exemplary embodiment, the present application also provides a method for preparing a copper-chromium alloy. Unlike the aforementioned embodiment, in this embodiment, chromium, lanthanum (La) and copper are placed in a non-vacuum medium-frequency induction furnace at a temperature of 1200°C for smelting; in addition, in this embodiment, while applying mechanical vibration, ultrasonic vibration is further introduced. The high-frequency vibration of the ultrasonic wave can produce a local high-pressure and high-temperature environment, which helps to break the atomic clusters in the copper-chromium alloy melt and promote the formation of more uniformly distributed new crystal nuclei. More crystal nuclei mean that the final grains are finer and evenly distributed. In addition, the cavitation effect (i.e., the rapid formation and rupture of tiny bubbles) generated by ultrasonic vibration can generate strong turbulence in the copper-chromium alloy melt, which can accelerate the diffusion rate of solute elements (such as chromium, lanthanum, etc.) in the base metal, and ensure that the components are mixed more evenly. Further, the strong turbulence and cavitation effect caused by ultrasonic vibration can accelerate heat transfer, which can prompt the copper-chromium alloy melt to reach the solidification temperature faster, thereby shortening the time of the entire casting process.

[0050] In another exemplary embodiment, the present application also provides a method for preparing a copper-chromium alloy. Unlike the above-mentioned embodiment, in this embodiment, chromium, lanthanum (La) and copper are placed in a non-vacuum medium-frequency induction furnace at a temperature of 1250°C for melting. In addition, in this embodiment, after the casting is completed, the copper-chromium alloy blank is immediately subjected to low-temperature annealing heat treatment. During the high-temperature smelting (1250°C) and the subsequent rapid cooling process, large thermal stresses are easily generated inside the copper-chromium alloy blank. By immediately performing low-temperature annealing, these stresses can be released to a certain extent to prevent cracks or deformation caused by stress concentration. In addition, low-temperature annealing can promote the process of transformation of certain unstable phases in the copper-chromium alloy blank to stable phases, and can ensure the stability of the microstructure of the copper-chromium alloy blank. Further, after low-temperature annealing, the residual stress of the copper-chromium alloy blank can be reduced, so that the internal structure of the copper-chromium alloy blank is more stable, and permanent deformation is not easy to occur even when subjected to external mechanical forces.

[0051] In the above embodiment, it should be noted that the reason why chromium, lanthanum and copper are smelted at a temperature of 1100°C to 1250°C is that within this temperature range, the atomic movement between various elements is more active, which is conducive to their diffusion and uniform distribution, thereby forming a more uniform alloy structure. In addition, this temperature range is a relatively low temperature range that is sufficient to achieve the goal, which can reduce energy consumption while ensuring the quality of the alloy.

[0052] Based on the above embodiments, after obtaining the copper-chromium alloy, the present application further requires solution treatment thereof, which specifically includes the following steps:

[0053] First, the copper-chromium alloy is placed in a medium-temperature preheating furnace (about 400° C. to 500° C.) for preheating, which helps to reduce the temperature difference between the copper-chromium alloy and the high temperature of the quenching furnace and prevent thermal shock and internal stress concentration caused by rapid temperature rise.

[0054] Secondly, the preheated copper-chromium alloy is placed in a vacuum quenching furnace and heated in stages, that is, first heated to about 700°C at a lower heating rate (such as 20°C per minute), and then the heating rate is increased (such as 30°C per minute) until the target temperature reaches 985°C. The staged heating method can ensure that the copper-chromium alloy is heated evenly and can gradually adapt to temperature changes to reduce the risk of thermal shock.

[0055] It should be noted that the present application adopts a dual-medium quenching method to cool the copper-chromium alloy after graded heating, that is, the copper-chromium alloy is first immersed in a molten salt bath (temperature is about 300°C to 400°C) for a short soak (for example, 5s to 10s), and then transferred to water or polymer quenching liquid to complete rapid cooling. Compared with the direct use of water or polymer quenching liquid, the molten salt bath provides a milder and more uniform cooling environment, which relieves internal stress through isothermal transformation and further refines the grain structure. In addition, compared with direct water cooling, the molten salt bath can also protect the surface of the copper-chromium alloy from oxidation and decarburization to a certain extent, so that it maintains a good surface finish.

[0056] Furthermore, after the solution treatment is completed, the present application also performs an aging treatment on the copper-chromium alloy, which specifically includes the following steps:

[0057] First, before the solution-treated copper-chromium alloy is loaded into the aging furnace, it is preheated in a low-temperature preheating zone (about 100°C to 200°C) for 30 minutes to reduce the thermal shock caused by the temperature difference, which helps prevent cracks or other defects in the copper-chromium alloy.

[0058] Secondly, the temperature is raised in stages, that is, it is first slowly raised to about 300°C at a rate of 5°C per minute, and after being kept stable for a period of time, it is raised to the final aging temperature of 475°C at a rate of 8°C per minute. After reaching the aging temperature, it is kept warm for 2 hours. The main purpose of this stage is to allow the alloy elements to begin to precipitate and form a stable phase structure. After the insulation is completed, the temperature is immediately reduced to 450°C and kept warm again at this temperature for 2 hours. This stage aims to further promote the formation of fine and evenly distributed precipitation phases to improve the hardness and strength of the copper-chromium alloy.

[0059] Finally, after the insulation is completed, the copper-chromium alloy is naturally cooled to 400°C. This stage can slow down the cooling rate, reduce the residual stress generated during the cooling process, and allow the precipitation phase to grow fully, which helps to reduce the risk of deformation or cracking caused by rapid cooling. When the temperature drops to 400°C, the copper-chromium alloy is quickly transferred to the polymer quenching liquid or air for rapid cooling to ensure that the precipitation phase is fixed, so as to obtain the ideal microstructure and performance.

[0060] Next, the present application compares the performance of the copper-chromium alloy prepared based on the above embodiments with the existing copper-chromium alloy. The comparison results are shown in Table 1:

[0061] Table 1

[0062]

[0063]

[0064] It can be seen from Table 1 that the copper-chromium alloy prepared by the method described in this application is significantly superior to the existing copper-chromium alloy materials in multiple key performance indicators. In particular, it performs particularly well in terms of electrical conductivity, hardness, tensile strength, dimensional stability, surface quality, and fatigue resistance, providing a more ideal material choice for the manufacture of high-performance power equipment.

[0065] Figure 2 FIG. 1 is a schematic diagram of the structure of a copper-chromium alloy contact seat provided by another exemplary embodiment of the present application. Figure 2As shown, the copper-chromium alloy contact seat includes: a contact seat body 1, the contact seat body 1 is circular, a connecting block 4 is arranged at one side edge of the contact seat body 1, and the first wing plate 2-1 and the second wing plate 2-2 are symmetrically arranged on both sides of the connecting block 4, the first wing plate 2-1 and the second wing plate 2-2 both include a fixed side and an extended side, wherein the first wing plate 2-1 and the second wing plate 2-2 are connected to the connecting block 4 through the fixed side, and the extended sides of the first wing plate 2-1 and the second wing plate 2-2 extend along the edge of the contact seat body 1 to the side opposite to the connecting block 4, and the first wing plate 2-1 and the second wing plate 2-2 and the connecting block 4 form a fixed structure.

[0066] In this embodiment, the connecting block 4 can provide additional mechanical support to ensure that the contact seat can withstand external mechanical stress, such as vibration or impact, and internal electric force. The first wing plate 2-1 and the second wing plate 2-2 increase the rigidity of the edge area of ​​the contact seat, which helps to prevent the contact seat from deforming and can provide additional support points when installing contacts. The fixed structure formed by the first wing plate 2-1, the second wing plate 2-2 and the connecting block 4 can provide a stable foundation for the contact seat, so that the contact seat can maintain stable operation under high current and high voltage conditions, and can reduce the displacement or vibration of the contact caused by thermal expansion, electromagnetic force, etc.

[0067] It should be noted that the extended sides of the first wing plate 2-1 and the second wing plate 2-2 are not connected, that is, the fixed structure formed by the first wing plate 2-1, the second wing plate 2-2 and the connecting block 4 is an open structure. The fixed structure adopts an open design, firstly, it can avoid the stress concentration problem caused by thermal expansion and contraction or other external forces during installation or operation. When the contact seat expands or contracts due to temperature changes, the open structure allows a certain deformation space, which can prevent material fatigue or fracture that may be caused by excessive constraints. Second, the open structure can increase the space for air circulation, which helps to improve the efficiency of natural cooling, especially when working in a high temperature environment, it can effectively reduce the working temperature of the contact seat and extend its service life. Third, the open structure provides a direct and simple assembly path for the connection between the contact seat and the contact, without the obstruction of a closed frame, and the contact can be directly inserted or slid into the predetermined position of the contact seat, reducing the complex assembly steps and reducing the difficulty of installation.

[0068] In another exemplary embodiment, a connection hole 6 is provided at the central position of the contact base body 1 , and the contact base body 1 is connected to the copper-chromium alloy contact through the connection hole 6 .

[0069] In this embodiment, in addition to the mechanical fixing function, the connection hole 6 can also provide a current path for the contact fixed on the contact seat, and the connection hole 6 can accommodate a bolt or a screw, and the bolt or the screw passes through the connection hole 6 and is fixed to the corresponding external conductor using a nut, so that the contact can establish an electrical connection with the external circuit through the connection hole 6. By establishing an electrical connection, it is possible to ensure that the current path between the contact and the external conductor is smoother, which can not only improve the power transmission efficiency, but also reduce the heat generation of the contact when a large current passes through, which helps to keep the working temperature of the contact within a safe range, thereby slowing down the aging of the contact, so that the contact can maintain its physical and electrical properties for a longer time.

[0070] In another exemplary embodiment, heat dissipation holes 7 are arranged around the connection hole 6 .

[0071] In this embodiment, the heat dissipation holes 7 can increase the surface area of ​​the contact seat in contact with the external air, thereby improving the efficiency of natural convection and radiation heat dissipation, and helping to transfer the heat generated in the contact seat to the external environment. Figure 2 As shown, the heat dissipation hole 7 is designed to be an irregular ellipse, that is, the side of the heat dissipation hole 7 facing the connecting hole is inwardly concave, wherein the inwardly concave design can increase the surface area of ​​the edge of the heat dissipation hole 7 in contact with the surrounding air, thereby enhancing the efficiency of natural convection heat dissipation, and more surface contact allows more heat to be transferred through radiation and convection. In addition, compared with regular-shaped heat dissipation holes (such as round, square or regular elliptical shapes), irregular-shaped heat dissipation holes can better disperse the stress caused by temperature changes and avoid the formation of stress concentration points at specific locations of the contact seat (regular shapes have clear boundaries and corners, where material deformation is limited and high stress areas are easily formed. Especially under temperature cycling conditions, this stress concentration may cause cracks or other forms of damage. The edges of irregular shapes are smoother and have no obvious corners. A smooth transition of stress can be achieved through a gradual curvature radius, which helps to avoid excessive stress concentration at specific locations. When temperature changes cause the material to expand or contract, irregular shapes can distribute stress more evenly, reduce local stress peaks, and thus reduce the risk of material failure), thereby helping to prevent cracks or other damage to the contact seat due to thermal expansion and contraction.

[0072] In another exemplary embodiment, a connecting portion 5 is provided at the bottom of the contact seat body 1 , and the contact seat body 1 is connected to the static contact via the connecting portion 5 .

[0073] In this embodiment, the contact seat is connected to the static contact through the connecting part 5, which can form a low-resistance electrical connection path, ensuring that the current can be smoothly transmitted from the external circuit to the static contact, and then the entire circuit is closed through the copper-chromium alloy contact, which helps to reduce energy loss and improve power transmission efficiency.

[0074] In another exemplary embodiment, a mounting plate 3 is disposed on the outer side of the connection block 4 .

[0075] In this embodiment, on the one hand, the mounting plate 3 can provide additional mechanical support for the contact holder to ensure that it can withstand external mechanical stress, such as vibration or impact, and internal electric force. On the other hand, the mounting plate 3 can help disperse the stress from external loads or internal electric forces to avoid the formation of excessive stress concentration points at specific locations, thereby reducing the risk of cracks or breakage of the contact holder. In addition, if Figure 2 As shown, the mounting plate 3 is provided with mounting holes 8, through which the contact holder can be conveniently fixed to the switch device or other related components.

[0076] The above are only preferred embodiments of the present application, and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A copper-chromium alloy, characterized in that: The components of the copper-chromium alloy and the mass percentage of each component are: Chromium: 0.2wt% to 0.5wt%; Lanthanum: 0.05wt% to 0.1wt%; Copper: Balance.

2. A method for preparing a copper-chromium alloy, characterized in that: The preparation method comprises: smelting chromium, lanthanum and copper in a set ratio to obtain a copper-chromium alloy melt; Casting the copper-chromium alloy melt to obtain a copper-chromium alloy blank; Forging the copper-chromium alloy blank to obtain a copper-chromium alloy bar; Drawing the copper-chromium alloy bar to obtain a drawn copper-chromium alloy bar; The drawn copper-chromium alloy bar is sawn into a set length, the sawn copper-chromium alloy bar is induction heated, and the induction heated copper-chromium alloy bar is extruded to obtain the copper-chromium alloy.

3. The method for preparing a copper-chromium alloy according to claim 2, characterized in that: Chromium, lanthanum and copper are smelted at a temperature of 1100°C to 1250°C.

4. The method for preparing a copper-chromium alloy according to claim 2, characterized in that: Forging the copper-chromium alloy blank comprises: Preheating the copper-chromium alloy blank; Performing preliminary forging on the preheated copper-chromium alloy blank; Performing finish forging on the copper-chromium alloy blank after preliminary forging; The copper-chromium alloy blank after finish forging is cooled.

5. The method for preparing a copper-chromium alloy according to claim 2, characterized in that: The copper-chromium alloy bar is drawn by a multi-stage progressive drawing method.

6. The method for preparing a copper-chromium alloy according to claim 2, characterized in that: The preparation method further comprises: The copper-chromium alloy is subjected to a solid solution treatment.

7. The method for preparing a copper-chromium alloy according to claim 2, characterized in that: The preparation method further comprises: The copper-chromium alloy after the solution treatment is subjected to aging treatment.

8. A copper-chromium alloy contact seat, characterized in that: The copper-chromium alloy contact seat is made of the copper-chromium alloy according to claim 1, and the copper-chromium alloy contact seat comprises: A contact base body (1), a connecting block (4) is arranged at the edge of one side of the contact base body (1), and a first wing plate (2-1) and a second wing plate (2-2) are symmetrically arranged on both sides of the connecting block (4), and the first wing plate (2-1) and the second wing plate (2-2) both include a fixed side and an extended side, wherein the first wing plate (2-1) and the second wing plate (2-2) are connected to the connecting block (4) through the fixed side, and the extended sides of the first wing plate (2-1) and the second wing plate (2-2) extend along the edge of the contact base body (1) to the side opposite to the connecting block (4), and the first wing plate (2-1) and the second wing plate (2-2) and the connecting block (4) form a fixed structure.

9. The copper-chromium alloy contact seat according to claim 8, characterized in that: A connection hole (6) is provided at a central position of the contact seat body (1), and the contact seat body (1) is connected to a copper-chromium alloy contact via the connection hole (6).

10. The copper-chromium alloy contact seat according to claim 9, characterized in that: Heat dissipation holes (7) are arranged around the connection hole (6).

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