Copper-chromium contact, preparation method thereof and high-voltage vacuum circuit breaker

Abstract

The invention relates to a copper-chromium contact, a preparation method thereof and a high-voltage vacuum circuit breaker. The copper-chromium contact comprises a base body structure and a plurality of unit structures, the unit structures are longitudinally-extending cylinder structures, and the unit structures are longitudinally arranged in parallel in a honeycomb shape and embedded into the base body structure. Each unit structure comprises a framework area and a functional area, the framework area extends in the longitudinal direction, and the functional area surrounds the framework area in the circumferential direction; wherein the copper content ratio of the functional area is higher than the copper content ratio of the matrix structure, and the copper content ratio of the matrix structure is higher than the copper content ratio of the skeleton area. According to the copper-chromium contact, a three-dimensional interpenetrating structure which is high in interface bonding force and high in compactness can be formed between copper-chromium alloy phases with different component contents, then the excellent conductivity of copper is brought into full play, excellent arc ablation resistance and high-voltage resistance are provided with the help of chromium, and the copper-chromium contact has excellent conductivity and arc resistance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of metal matrix composites, in particular to a copper-chromium contact and a preparation method thereof, and a high-voltage vacuum circuit breaker. BACKGROUND

[0002] The copper-chromium alloy contact is one of the most widely used materials in the current medium and high-voltage vacuum circuit breaker. Its performance directly affects the reliability and service life of the power equipment.

[0003] The traditional preparation method of the copper-chromium contact mainly includes powder metallurgy, mechanical alloying and hot isostatic pressing sintering. Although these methods can realize basic alloying, there are problems of uneven distribution of chromium phase in the matrix, poor interface bonding and high porosity of the material, which leads to the performance of copper-chromium being not coordinated, so that the contact is difficult to have excellent electrical conductivity and durability. SUMMARY

[0004] Therefore, it is necessary to provide a copper-chromium contact with a special structural design, a preparation method thereof and a high-voltage vacuum circuit breaker. In the structure of the copper-chromium contact, the copper-chromium material can form an interpenetrating structure with strong interface bonding force and high density, and the obtained copper-chromium contact has excellent electrical conductivity and arc resistance.

[0005] In a first aspect, the present application provides a copper-chromium contact.

[0006] The copper-chromium contact comprises a matrix structure and a plurality of unit structures, the unit structure is a longitudinally extending column structure, and a plurality of the unit structures are arranged in a honeycomb shape and longitudinally parallel and embedded in the matrix structure; the unit structure comprises a skeleton region and a functional region, the skeleton region extends longitudinally, and the functional region circumferentially surrounds the skeleton region; wherein the copper content proportion of the skeleton region is higher than the copper content proportion of the matrix structure, and the copper content proportion of the matrix structure is higher than the copper content proportion of the functional region.

[0007] In some embodiments, the copper content in the matrix structure is 65% to 75% by mass percentage, and the chromium content is 25% to 35% by mass percentage; and / or

[0008] the copper content in the functional region is 38% to 43% by mass percentage, and the chromium content is 57% to 62% by mass percentage; and / or

[0009] the copper content in the skeleton region is 86% to 92% by mass percentage, and the chromium content is 8% to 14% by mass percentage.

[0010] In some embodiments, the transverse cross section of the unit structure is one of a circle, a square and a regular hexagon.

[0011] In some embodiments, the skeleton region is coaxial with the unit structure.

[0012] In some embodiments, the copper-chromium contactor is a cylinder with a diameter of 1.5 cm to 2.5 cm; and / or

[0013] the unit structure is a cylinder with a diameter of 0.2 mm to 4 mm

[0014] In some embodiments, the spacing between two adjacent unit structures is 0.2 mm to 4 mm.

[0015] In a second aspect, the application provides a preparation method of the copper-chromium contactor.

[0016] A preparation method of the copper-chromium contactor, comprising the following steps:

[0017] obtaining a three-dimensional model of the copper-chromium contactor;

[0018] under a protective atmosphere, preparing a first embryonic structure by layer-by-layer laying and melting forming of the preparation raw materials of the base structure, the skeleton region and the functional region according to the structure of the three-dimensional model through an additive manufacturing technology;

[0019] performing hot isostatic pressing treatment on the first embryonic structure to prepare a second embryonic structure;

[0020] under a protective atmosphere, performing annealing treatment on the second embryonic structure to form the copper-chromium contactor.

[0021] In some embodiments, the temperature of the hot isostatic pressing treatment is 950℃ to 1200℃;

[0022] and / or, the pressure of the hot isostatic pressing treatment is 80 MPa to 120 MPa;

[0023] and / or, the treatment time of the hot isostatic pressing treatment is 0.5 h to 1.5 h.

[0024] In some embodiments, the additive manufacturing technology includes laser selective melting technology and electron beam selective melting technology.

[0025] In a third aspect, the application provides a high-voltage vacuum circuit breaker. The high-voltage vacuum circuit breaker comprises the copper-chromium contactor or the copper-chromium contactor prepared by the preparation method.

[0026] The copper chromium contact has the functional area, the base structure and the skeleton area with the copper content ratio increasing in turn. The functional area circumferentially surrounds the skeleton area to form a unit structure. The unit structure is arranged in parallel in a honeycomb shape and embedded in the base structure to form a longitudinal through structure. The copper chromium contact has a three-dimensional interpenetrating structure with strong interface bonding force and high density between the copper chromium alloy phases with different component contents. The copper chromium contact has excellent electric conductivity and arc resistance and high pressure resistance. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0028] Figure 1 It is a structure schematic diagram of the transverse section of the copper chromium contact in an embodiment of the present application.

[0029] Figure 2 It is a flow chart of the preparation method of the copper chromium contact in an embodiment of the present application.

[0030] Figure 3 It is a morphology diagram of the copper chromium contact in embodiment 1 of the present application, wherein (a) is a morphology diagram of the transverse section of the copper chromium contact, (b) is a local enlarged view of the S2 area in (a), (c) is a local enlarged view of the S3 area in (a), and (d) is a local enlarged view of the yellow frame area in (c). DETAILED DESCRIPTION

[0031] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application will be described in detail. In the following description, a lot of specific details are described in order to fully understand the present application. However, the present application can be implemented in many other ways different from the description herein, and those skilled in the art can make similar improvements without departing from the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0032] In the description of the present application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise explicitly specified. In the present application, the meaning of "at least one" is more than one, such as one, two and more than two. The meaning of "multiple" or "several" is at least two, such as two, three, etc.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0034] When a numerical range is disclosed herein, the range is considered continuous and includes the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to integers, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe a feature or characteristic, the ranges may be combined. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are incorporated.

[0035] Unless otherwise specified, all steps in this application may be performed sequentially or randomly. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the method may also include step (c), indicating that step (c) may be added to the method in any order. For example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0036] In this application, "above" or "below" includes the number itself. For example, "below 1" includes 1.

[0037] Unless otherwise specified, the temperature parameters in this application are permitted to be either constant-temperature treatment or variations within a certain temperature range. It should be understood that the constant-temperature treatment allows temperature fluctuations within the precision range of the instrument control, such as ±5℃, ±4℃, ±3℃, ±2℃, or ±1℃.

[0038] As electrical equipment evolves towards higher power, miniaturization, and longer lifespan, electrical contact materials, as key functional components, must possess excellent conductivity, wear resistance, arc erosion resistance, and corrosion resistance. Traditional silver-based contact materials (such as Ag-CdO) offer good conductivity but suffer from cadmium toxicity and are prone to failure under high loads due to arc erosion. While pure copper contacts are low-cost and offer excellent conductivity, their wear resistance and oxidation resistance are poor, and prolonged use can lead to increased contact resistance due to a thickened surface oxide film, affecting equipment reliability. Therefore, developing novel environmentally friendly, high-performance composite contact materials has become a current research hotspot.

[0039] Copper-chromium alloy electrical contacts are one of the most widely used materials in medium- and high-voltage vacuum circuit breakers. Their performance directly affects the reliability and service life of power equipment.

[0040] Traditional methods for preparing copper-chromium contacts mainly include powder metallurgy, mechanical alloying, and hot isostatic pressing (HIP). While these methods can achieve basic alloying, they generally suffer from uneven distribution of the chromium phase in the matrix, poor interfacial bonding, and high material porosity. This leads to a mismatch between the properties of copper and chromium, making it difficult for the contacts to simultaneously possess excellent conductivity and durability.

[0041] Based on this, the first aspect of this application provides a copper-chromium contact that has both excellent conductivity and arc resistance.

[0042] For example, please see Figure 1 , Figure 1 This is a schematic diagram of the transverse cross-section of a copper-chromium contact according to one embodiment of this application. Figure 1 As shown, the copper-chromium contact includes a base structure and multiple unit structures. Each unit structure is a longitudinally extending columnar structure, with multiple unit structures arranged longitudinally in a honeycomb pattern and embedded within the base structure. Each unit structure includes a skeleton area and a functional area. The skeleton area extends longitudinally, and the functional area circumferentially surrounds the skeleton area. The copper content in the skeleton area is higher than that in the base structure, and the copper content in the base structure is higher than that in the functional area. The honeycomb arrangement of the unit structures means that the longitudinal projections of multiple unit structures are arranged according to the intersections and centers of hexagons. That is, the lines connecting the outer centers of multiple unit structures form a hexagon. For unit structures whose center projection is inside the hexagon, there are six regularly arranged unit structures on each side, forming a periodic arrangement. The minimum number of units in the honeycomb arrangement is seven. Figure 1 The situation is shown below.

[0043] In this embodiment, the unit structure includes a longitudinally extending skeleton area and a functional area, wherein the functional area circumferentially surrounds the skeleton area, and the shape of any transverse cross section of the unit structure is consistent.

[0044] In this embodiment, the copper content of the skeleton region is higher than that of the substrate structure, and the copper content of the substrate structure is higher than that of the functional region. In this structure, the high-copper-content skeleton region acts as the skeleton of the copper-chromium contact, thereby giving the copper-chromium contact good conductivity. The substrate structure has a moderate ratio of copper and chromium content to provide balanced durability and conductivity. The high-chromium-content functional region circumferentially surrounds the skeleton region, thereby providing good mechanical properties and avoiding static welding.

[0045] The aforementioned copper-chromium contact has functional areas, a matrix structure, and a skeleton area with progressively increasing copper content. By circumferentially surrounding the skeleton area to form a unit structure, and further arranging the unit structure in a honeycomb pattern and embedding it into the matrix structure, a three-dimensional interpenetrating structure with strong interfacial bonding and high density can be formed between copper-chromium alloy phases with different compositions. This fully utilizes the excellent conductivity of copper and provides excellent arc erosion resistance and high voltage resistance with the help of chromium, giving the copper-chromium contact both excellent conductivity and arc resistance.

[0046] In some embodiments, the copper content in the matrix structure is 65% to 75% by mass percentage. Optionally, the copper content in the matrix structure can be, but is not limited to, 65%, 66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74%, 75%, or other values ​​within the range of 65% to 75%.

[0047] In this embodiment, the chromium content can be considered equal to (100% - copper content). However, it should be understood that, limited by the purity of the copper and chromium sources, the chromium content is theoretically not equal to (100% - copper content), and other trace impurities are also present. The chromium content in the matrix structure is 25% to 35% by mass percentage. Optionally, the chromium content in the unit structure can be, but is not limited to, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, or other values ​​within the range of 25% to 35%.

[0048] In some embodiments, the copper content in the functional area is 38% to 43% by mass percentage. Optionally, the copper content in the functional area can be, but is not limited to, 38%, 39%, 40%, 41%, 42%, 43%, or other values ​​within the range of 38% to 43%.

[0049] In this embodiment, the chromium content in the functional area is 57% to 62% by mass percentage. Optionally, the chromium content in the functional area can be, but is not limited to, 57%, 58%, 59%, 60%, 61%, 62%, or other values ​​within the range of 57% to 62%.

[0050] In some embodiments, the copper content in the skeleton region is 86% to 92% by mass percentage. Optionally, the copper content in the skeleton region can be, but is not limited to, other values ​​within the range of 86%, 87%, 88%, 89%, 90%, 91%, 92%, or 86% to 92%.

[0051] In this embodiment, the chromium content in the skeleton region is 8% to 14% by mass percentage. Optionally, the chromium content in the skeleton region can be, but is not limited to, 8%, 9%, 10%, 11%, 12%, 13%, 14%, or other values ​​within the range of 8% to 14%.

[0052] In some embodiments, the transverse cross section of the unit structure has at least two mutually perpendicular first and second axes of symmetry.

[0053] In some embodiments, the transverse cross-section of the unit structure is one of a circle, a square, or a regular hexagon.

[0054] In some embodiments, the transverse cross-section of the unit structure is circular.

[0055] In some embodiments, the copper-chromium contact is a cylinder with a diameter of 1.5cm to 2.5cm.

[0056] In some embodiments, the unit structure is a cylinder with a diameter of 0.2 mm to 4 mm.

[0057] In some embodiments, the spacing between two adjacent unit structures is 0.2 mm to 4 mm.

[0058] In some implementations, the lateral extension width of the functional area is 5μm to 20μm.

[0059] In some embodiments, the unit structure extends longitudinally through the copper-chromium contact. Furthermore, the functional area and the skeleton area extend longitudinally through the copper-chromium contact.

[0060] In some implementations, the skeleton region is coaxial with the unit structure.

[0061] In some embodiments, on any transverse cross section of the copper-chromium contact, the distance from the center of each unit structure to the center of the cross section of the adjacent unit structure is equal.

[0062] The second aspect of this application provides a method for preparing the aforementioned copper-chromium contact.

[0063] Please see Figure 2 , Figure 2 This is a flowchart of a method for preparing a copper-chromium contact according to one embodiment of this application.

[0064] For example, a method for preparing a copper-chromium contact includes the following steps:

[0065] S1. Obtain a three-dimensional model of the copper-chromium contact. It can be understood that the structure of the three-dimensional model is the same as the structure of the copper-chromium contact described above.

[0066] S2. Under a protective atmosphere, the raw materials for the preparation of the matrix structure, skeleton region and functional region are laid layer by layer and melted into shape according to the structure of the three-dimensional model by additive manufacturing technology to prepare the first preform structure.

[0067] S3. The first embryonic structure is subjected to hot isostatic pressing to prepare the second embryonic structure.

[0068] S4. Under a protective atmosphere, the second preform structure is annealed to form a copper-chromium contact.

[0069] In some embodiments, the substrate is prepared using a first copper-chromium material, the framework region is prepared using a second copper-chromium material, and the functional region is prepared using a third copper-chromium material.

[0070] It is understandable that the copper content of the first copper-chromium material is 65%~75%, the copper content of the second copper-chromium material is 86%~92%, and the copper content of the third copper-chromium material is 38%~43%.

[0071] In some embodiments, the preparation methods of the first copper-chromium material, the second copper-chromium material, and the third copper-chromium material each independently include:

[0072] The copper source and chromium source are mixed in proportion to form a mixture;

[0073] The mixture is ball-milled and then dried.

[0074] In some embodiments, the copper source includes copper powder. Optionally, the copper source is electrolytic copper powder with a purity greater than 99.9%.

[0075] In some embodiments, the chromium source includes chromium powder. Optionally, the chromium source is atomized chromium powder with a purity greater than 99.5%.

[0076] In some embodiments, the D50 of the copper powder is 15 μm to 30 μm. Optionally, the D50 of the copper powder can be, but is not limited to, 15 μm, 20 μm, 25 μm, 30 μm, or other values ​​within the range of 15 μm to 30 μm.

[0077] In some embodiments, the D50 of the chromium powder is 15 μm to 40 μm. Optionally, the D50 of the chromium powder can be, but is not limited to, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, or other values ​​within the range of 15 μm to 40 μm.

[0078] In some embodiments, the mixture is ball-milled, stearic acid is added as a dispersant, the ball-milling time is 4 hours, the ball-to-material ratio is 10:1, and a uniform composite powder is obtained.

[0079] In some embodiments, the ball-to-material ratio for ball milling is (8-12):1. Optionally, the ball-to-material ratio for cryogenic ball milling can be, but is not limited to, 8:1, 9:1, 10:1, 11:1, 12:1, or other values ​​within the range of (8-12):1.

[0080] In some embodiments, the ball milling speed is 200 rpm to 300 rpm. Optionally, the speed of the cryogenic ball milling process can be, but is not limited to, 200 rpm, 300 rpm, 400 rpm, or other values ​​within the range of 200 rpm to 300 rpm.

[0081] In some embodiments, the cryo-ball milling treatment time is 3 to 5 hours. Optionally, the cryo-ball milling treatment time can be, but is not limited to, 3 hours, 4 hours, 5 hours, or other values ​​within the range of 3 to 5 hours.

[0082] In some embodiments, the hot isostatic pressing (HIP) temperature is 950°C to 1200°C. Optionally, the HIP temperature can be, but is not limited to, 950°C, 1000°C, 1050°C, 1100°C, 1150°C, 1200°C, or other values ​​within the range of 950°C to 1200°C.

[0083] In some embodiments, the pressure of hot isostatic pressing is 80 MPa to 120 MPa. Optionally, the pressure of hot isostatic pressing can be, but is not limited to, 80 MPa, 90 MPa, 100 MPa, 110 MPa, 120 MPa or other values ​​within the range of 80 MPa to 120 MPa.

[0084] In some embodiments, the hot isostatic pressing (HIP) treatment time is 0.5 h to 1.5 h. Optionally, the HIP treatment time can be, but is not limited to, 0.5 h, 1 h, 1.5 h, or other values ​​within the range of 0.5 h to 1.5 h.

[0085] In some implementations, additive manufacturing technologies include selective laser melting and selective electron beam melting.

[0086] In some embodiments, the first embryo structure is prepared by selective laser melting.

[0087] In some embodiments, the laser selective melting technology has a laser power of 200W~300W, a scanning speed of 600mm / s~800mm / s, a scanning spacing of 40μm~80μm, and adopts a continuous incremental printing strategy.

[0088] In some embodiments, step S3 includes the following steps:

[0089] Under a protective atmosphere, a first annealing treatment is performed at 850℃~950℃, followed by a second annealing treatment at 600℃~700℃. The first annealing treatment at high temperature stabilizes the microstructure of the second ligand, and subsequent tempering at a lower temperature further improves interfacial toughness, resulting in a high-density copper-chromium contact.

[0090] In some embodiments, the processing time for the first annealing treatment is 1.5h to 2.5h. Optionally, the processing time for the first annealing treatment can be, but is not limited to, 1.5h, 2h, 2.5h, or other values ​​within the range of 1.5h to 2.5h.

[0091] In some embodiments, the processing time for the second annealing process is 0.5h to 1.5h. Optionally, the processing time for the second annealing process can be, but is not limited to, 0.5h, 1h, 1.5h, or other values ​​within the range of 0.5h to 1.5h.

[0092] A third aspect of this application provides a high-voltage vacuum circuit breaker. Exemplarily, the high-voltage vacuum circuit breaker includes the copper-chromium contacts described above or copper-chromium contacts prepared by the aforementioned method.

[0093] The present application will be further described in detail below with reference to specific embodiments.

[0094] Unless otherwise specified, the raw materials used in the following specific embodiments and comparative examples are all commercially available products; the instruments used are all commercially available products; and the processes used are all conventionally selected by those skilled in the art unless otherwise specified.

[0095] Example 1

[0096] This embodiment provides a copper-chromium contact.

[0097] The preparation method of copper-chromium contacts is as follows:

[0098] S1. Construct a 3D model of the copper-chromium contact using graphics software. The copper-chromium contact consists of a base structure and unit structures. Multiple unit structures are arranged longitudinally in a honeycomb pattern and embedded in the base structure. Each unit structure consists of a skeleton area and a functional area, with the functional area circumferentially surrounding the skeleton area. Specifically, the copper-chromium contact is a cylinder with a diameter of 2cm and a height of 0.3cm; the skeleton area is a cylinder with a diameter of 2.4985mm and a height of 0.3cm; and the functional area is a ring with an inner diameter of 2.4985mm, an outer diameter of 2.5mm, and a height of 0.3cm. The spacing between adjacent unit structures is 0.5mm. The central unit structure is coaxial with the copper-chromium contact. The total number of unit structures is 19.

[0099] S2. Under an argon atmosphere, the raw materials for preparing the matrix structure, framework area and functional area are filled into the powder bed of an EOS M290 SLM equipment. The laser power is set to 250W and the scanning speed is 700mm / s. A linear continuous incremental printing strategy is adopted to lay and melt the materials layer by layer according to the structure of the three-dimensional model through laser selective melting technology to prepare the first preform structure.

[0100] The raw material for preparing the matrix structure is a first copper-chromium material, the raw material for preparing the framework region is a second copper-chromium material, and the raw material for preparing the functional region is a third copper-chromium material.

[0101] Electrolytic copper powder with a D50 of 20μm and atomized chromium powder with a D50 of 30μm were mixed in ratios of 7:3, 4:6, and 9:1 to form mixtures respectively.

[0102] The mixture was ball-milled separately using anhydrous ethanol as the medium, with 1 wt% stearic acid added, a ball-to-material ratio of 10:1, a speed of 250 rpm, and a milling time of 3 hours. After being vacuum-dried at 60℃ for 1 hour, a first copper-chromium material with a copper content of 70% and a chromium content of 30%, a second copper-chromium material with a copper content of 90% and a chromium content of 10%, and a third copper-chromium material with a copper content of 40% and a chromium content of 60% were obtained.

[0103] S3. The first embryo structure is subjected to hot isostatic pressing at 100MPa and 1050℃ for 1 hour to form the second embryo structure.

[0104] S4. Under an argon atmosphere, the second preform structure is annealed, first at 900℃ for 2 hours, and then at 650℃ for 1 hour to form a copper-chromium contact.

[0105] Please see Figure 3 , Figure 3 The following are topographic images of the copper-chromium contact in this embodiment, wherein (a) is a topographic image of the transverse cross section of the copper-chromium contact, (b) is a partial enlarged view of region S2 in (a), (c) is a partial enlarged view of region S3 in (a), and (d) is a partial enlarged view of region in yellow box in (c).

[0106] Test case

[0107] The composite contact of Example 1 was subjected to performance testing. The density was determined by Archimedes method, the resistivity was determined by four-probe method, and the erosion rate was tested by arc test (10kA, 100 cycles). The test results are shown in Table 1.

[0108] Table 1 Performance test data of the composite contact in Example 1

[0109]

[0110] From Table 1 and Figure 3As can be seen, in the structure of the aforementioned copper-chromium contact, the skeleton region, functional region, and matrix structure are tightly integrated, and the synergistic effect of different structures enhances the contact material's resistance to arc erosion and impact. During the breaking process, region S1 provides excellent electrical and thermal conductivity channels, ensuring the electrical and thermal conductivity of the contact material; region S2 can resist most impact forces, reducing the large amount of splashing loss of molten Cu in the molten area, thereby maintaining contact quality and extending service life; at the same time, region S3 acts as a boundary line, preventing a large amount of molten Cu from entering other areas, thus ensuring the key channel for current transmission and further improving the contact's resistance to arc erosion. The aforementioned copper-chromium material can form a highly dense double-layer longitudinal interpenetrating structure with strong interfacial bonding, resulting in copper-chromium contacts with excellent electrical conductivity and arc resistance.

[0111] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0112] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this invention patent should be determined by the appended claims, and the specification can be used to interpret the content of the claims.

Claims

1. A copper-chromium contact, characterized in that, The system includes a matrix structure and multiple unit structures. Each unit structure is a longitudinally extending column structure, and the multiple unit structures are arranged in a honeycomb pattern, longitudinally parallel and embedded in the matrix structure. Each unit structure includes a skeleton region and a functional region. The skeleton region extends longitudinally, and the functional region circumferentially surrounds the skeleton region. The copper content of the skeleton region is higher than that of the matrix structure, and the copper content of the matrix structure is higher than that of the functional region.

2. The copper-chromium contact according to claim 1, characterized in that, The matrix structure contains 65% to 75% copper and 25% to 35% chromium by weight; and / or The functional area contains 38%–43% copper and 57%–62% chromium; and / or The copper content in the skeleton region is 86%~92%, and the chromium content is 8%~14%.

3. The copper-chromium contact according to any one of claims 1 to 2, characterized in that, The transverse cross-section of the unit structure is one of a circle, a square, or a regular hexagon.

4. The copper-chromium contact according to claim 3, characterized in that, The skeleton region is coaxial with the unit structure.

5. The copper-chromium contact according to claim 3, characterized in that, The copper-chromium contact is a cylinder with a diameter of 1.5cm to 2.5cm; and / or The unit structure is a cylinder with a diameter of 0.2mm to 4mm.

6. The copper-chromium contact according to claim 5, characterized in that, The spacing between two adjacent unit structures is 0.2mm to 4mm.

7. A method for preparing a copper-chromium contact according to any one of claims 1 to 6, characterized in that, Includes the following steps: Obtain a three-dimensional model of the copper-chromium contact; Under a protective atmosphere, the raw materials for preparing the matrix structure, skeleton region and functional region are laid layer by layer and melted into shape according to the structure of the three-dimensional model by additive manufacturing technology to prepare the first preform structure. The first embryo structure is subjected to hot isostatic pressing to prepare the second embryo structure. The second preform structure is annealed under a protective atmosphere to form the copper-chromium contact.

8. The method for preparing a copper-chromium contact according to claim 7, characterized in that, The hot isostatic pressing treatment is performed at a temperature of 950℃~1200℃; and / or The pressure of the hot isostatic pressing treatment is 80MPa~120MPa; and / or The hot isostatic pressing process takes 0.5h to 1.5h.

9. The method for preparing a copper-chromium contact according to claim 7, characterized in that, The additive manufacturing technologies include laser selective melting and electron beam selective melting.

10. A high-voltage vacuum circuit breaker, characterized in that, The copper-chromium contact includes the copper-chromium contact as described in any one of claims 1 to 6 or the copper-chromium contact prepared by the preparation method described in any one of claims 7 to 9.

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