High-conductivity wear-resistant copper alloy and preparation method and application thereof

Abstract

The invention relates to the technical field of copper alloys, in particular to a high-conductivity wear-resistant copper alloy and a preparation method and application thereof. A high-conductivity wear-resistant copper alloy comprises, by mass, 3-6% of nickel, 2-5% of tin, 1-3% of zinc, 0.1-0.5% of a rare earth element, 0.8-1.2% of a carbon nanotube-copper intermediate alloy and the balance copper, the rare earth element is one of cerium and lanthanum, the conductivity of the high-conductivity wear-resistant copper alloy is larger than or equal to 94% IACS, and the Vickers hardness of the high-conductivity wear-resistant copper alloy is larger than or equal to 120 HV. By regulating and controlling the mass ratio of nickel (Ni) to tin (Sn), adding the rare earth element and the carbon nanotube-copper intermediate alloy and accurately controlling the preparation process, the conductivity, wear resistance and mechanical property of the copper alloy material are remarkably improved, and the copper alloy material has wide application prospects in the fields of power transmission, high-speed transportation, ocean engineering and the like.

Description

Technical Field

[0001] This application relates to the technical field of copper alloys, and particularly relates to a highly conductive and wear-resistant copper alloy, a preparation method thereof, and an application thereof. Background Art

[0002] A copper alloy refers to a solid product with metallic properties obtained by mixing and melting copper with another metal or several metals or non-metals and then cooling and solidifying. At present, some related copper alloys still need to be further improved in terms of having high strength, high toughness, high wear resistance, and high conductivity to meet the growing industrial demands. Summary of the Invention

[0003] The purpose of this application is to provide a highly conductive and wear-resistant copper alloy, a preparation method thereof, and an application thereof in view of the deficiencies of the current technology. In this application, by adjusting the mass ratio of nickel (Ni) to tin (Sn), the two cooperate to form a nanoscale intermetallic compound (Ni3Sn), reducing the influence of lattice distortion on conductivity, and at the same time improving the wear resistance and creep resistance of the alloy; by adding rare earth elements to purify the grain boundaries, reducing electron scattering, improving conductivity and toughness; in addition, this application utilizes the fact that the surface of carbon nanotubes has abundant hydroxyl-containing functional groups, and hydroxylphenylethanolamine is used to carry out nitrogen modification on the carbon nanotubes. Through the nitrogen-containing groups and hydroxyl-containing groups, copper elements and copper powder can be fully dispersed, and a carbon nanotube-copper master alloy with smaller particle size is prepared; thereby further improving the dispersion of carbon nanotubes in the finally prepared copper alloy material, strengthening the effective combination of carbon nanotubes and copper alloy, and significantly improving the mechanical properties and electrical conductivity of the copper alloy material. The highly conductive and wear-resistant copper alloy prepared in this application has excellent electrical conductivity, wear resistance, and a balance of high strength and toughness, and is suitable for applications such as power transmission busbars, high-speed train contact wires, or marine engineering corrosion-resistant connectors.

[0004] In the first aspect, this application provides a highly conductive and wear-resistant copper alloy, adopting the following technical solution: A highly conductive and wear-resistant copper alloy, by mass percentage, includes the following preparation raw materials: nickel 3-6%, tin 2-5%, zinc: 1-3%, rare earth element: 0.1-0.5%, carbon nanotube-copper master alloy 0.8-1.2%, and the balance is copper. Among them, the rare earth element is one of cerium and lanthanum. The conductivity of the highly conductive and wear-resistant copper alloy ≥94% IACS (International Annealed Copper Standard), and the Vickers hardness ≥120 HV.

[0005] By adopting the above technical solution, the synergistic effect of nickel (Ni, 3 - 6%) and tin (Sn, 2 - 5%) forms a nanoscale Ni3Sn phase in the alloy. This phase has high hardness and thermal stability, which can significantly improve the wear resistance and creep resistance of the alloy. Traditional solid solution strengthening elements (such as Sn) are prone to causing lattice distortion, increasing electron scattering, and reducing electrical conductivity. However, Ni3Sn precipitates uniformly in the form of nanoparticles, avoiding excessive interference with the copper matrix lattice, thereby maintaining high electrical conductivity (≥94% IACS) while strengthening the alloy. The optimized ratio of Ni and Sn ensures the uniform distribution of the Ni3Sn phase in the matrix, which not only acts as a dispersion strengthening phase to improve mechanical properties but also maintains electrical conductivity by reducing lattice distortion. In addition, the high-temperature stability of Ni3Sn can inhibit creep and is suitable for high-load and high-temperature environments. The role of zinc (Zn, 1 - 3%): Zn forms a limited solid solution in the copper matrix, slightly increasing the matrix strength and enhancing the oxidation resistance of the alloy. The Zn content is controlled at 1 - 3% to avoid a significant decrease in conductivity caused by excessive amounts (the resistivity of Zn is higher than that of Cu), balancing the requirements of strength and conductivity. The role of rare earth elements (Ce / La, 0.1 - 0.5%): Rare earth elements (Ce or La) react with impurities such as oxygen and sulfur to form high-melting-point compounds (such as Ce2O3), reducing grain boundary impurity segregation, reducing electron scattering, and enhancing electrical conductivity. Rare earth elements inhibit grain growth by adsorbing at grain boundaries to hinder grain boundary migration, refining the grain size, and improving the strength and toughness of the alloy. The purification effect of rare earth elements combined with the dispersion strengthening of Ni3Sn further optimizes the grain boundary structure, reduces defects, and improves comprehensive performance. The role of carbon nanotube - copper master alloy (0.8 - 1.2%): Dispersion strengthening and construction of a conductive network: Nitrogen doping of carbon nanotubes (CNTs) is carried out by hydroxybenzyl ethanolamine to introduce nitrogen-containing groups (such as amino groups), enhancing the interfacial bonding force between CNTs and the copper matrix. At the same time, the hydroxyl functional groups are used to improve the dispersion of CNTs in copper powder. The modified CNTs and copper powder are pre-dispersed by the melting method to form a carbon nanotube - copper master alloy with a smaller particle size, avoiding the agglomeration of CNTs in the final alloy and ensuring their uniform distribution. The high strength and high electrical conductivity (1D electron transport channel) of CNTs are combined with the copper matrix to form a three-dimensional conductive network, and at the same time, the dislocation movement is hindered by the "pinning effect", significantly improving the mechanical properties (hardness ≥120HV) and electrical conductivity of the alloy. The matrix role of copper (the balance): The copper matrix provides high electrical conductivity (the electrical conductivity of pure copper is 100% IACS), and the optimized design of other elements ensures the minimum loss of its electrical conductivity. The ductility of copper provides a toughness basis for the alloy, and together with other strengthening phases (Ni3Sn, CNTs), it achieves a balance of "high strength - high toughness". The Ni3Sn phase and CNTs together act as dispersion strengthening phases, improving wear resistance and strength through chemical bonding and physical pinning effects respectively. At the same time, the conductive network of CNTs compensates for the slight impact of Ni3Sn on electrical conductivity.Rare earth elements purify grain boundaries, reduce electron scattering, and jointly enhance electrical conductivity and mechanical properties with fine grain strengthening (rapid cooling process). In summary, through the regulation of the Ni-Sn ratio, rare earth grain boundary purification, CNTs dispersion strengthening, and process optimization, this copper alloy has achieved a synergistic improvement in high electrical conductivity (≥94% IACS), high hardness (≥120 HV), and wear resistance, and is suitable for power transmission busbars, high-speed train contact wires, or marine engineering corrosion-resistant connectors.

[0006] Preferably, the mass ratio of nickel to tin is (1.2 - 1.5):1, and the two synergistically form nanoscale intermetallic compounds (Ni3Sn), enhancing the wear resistance and creep resistance of the alloy.

[0007] By adopting the above technical solution, the main function of controlling the mass ratio of nickel (Ni) to tin at 1.2 - 1.5:1 is to promote the formation of nanoscale intermetallic compound Ni3Sn in the high-conductivity wear-resistant copper alloy. This compound can enhance the wear resistance and creep resistance of the alloy. At the same time, due to its nanoscale size, it can effectively reduce the negative impact on electrical conductivity and ensure that the alloy has high electrical conductivity. This ratio enhances the mechanical properties of the alloy by forming nanoscale hard phases while maintaining its excellent electrical conductivity.

[0008] Preferably, the rare earth element is cerium, and the addition amount is 0.2 - 0.3%, which is used to refine grains.

[0009] Preferably, the carbon nanotube - copper master alloy, by mass, includes the following preparation raw materials: 15 - 18 parts of hydroxylated carbon nanotubes, 800 parts of ethanol, 20 - 25 parts of copper ethanolate, 20 - 25 parts of copper powder, 2 - 3 parts of hydroxybenzene ethanolamine, and 100 - 110 parts of tris(hydroxymethyl)aminomethane hydrochloride solution with a pH of 7.3.

[0010] Preferably, the preparation method of the carbon nanotube - copper master alloy includes the following steps: S51. According to the mass, mix hydroxylated carbon nanotubes, hydroxybenzene ethanolamine, and ethanol, and perform ultrasonic treatment for 30 - 40 minutes to obtain a carbon nanotube dispersion; S52. According to the mass, add copper ethanolate, copper powder, and tris(hydroxymethyl)aminomethane hydrochloride solution to the carbon nanotube dispersion, stir evenly, then heat up to 52°C and react for 4 hours, concentrate to dryness, and collect the solid phase; S53. Calcinate the solid phase in a reducing atmosphere at 1210 - 1220°C for 3.5 - 4 hours, and cool to room temperature to obtain the carbon nanotube - copper master alloy, wherein the reducing atmosphere is a mixed gas of argon and hydrogen, and the volume fraction of hydrogen is 12 - 15%.

[0011] By adopting the above technical solution, hydroxytyramine reacts with the hydroxyl groups on the surface of carbon nanotubes through amino groups to form a nitrogen-doped structure, enhancing the dispersibility and interfacial binding force. Combining with ultrasonic treatment (S51), uniform dispersion of carbon nanotubes is achieved; the Tris-HCl buffer solution regulates the reaction environment: the tris(hydroxymethyl)aminomethane hydrochloride solution with a pH of 7.3 provides a stable alkaline environment, promoting the hydrolysis of copper ethoxide (Cu(OEt)2) into nano-copper particles, which together with copper powder serve as copper sources and are uniformly coated on the surface of carbon nanotubes (S52). Construction of the carbon nanotube-copper composite structure: the decomposition of copper ethoxide provides highly active copper nanoparticles, which together with copper powder form a copper matrix and are tightly bound to carbon nanotubes through chemical bonding, reducing interfacial defects. High-temperature reduction and calcination (S53): in an argon-hydrogen mixed atmosphere (H2 accounting for 12-15%), hydrogen reduces copper oxides and cleans the surface of carbon nanotubes, enhancing interfacial binding; high temperature at 1210-1220 °C promotes the metallurgical bonding between carbon nanotubes and the copper matrix, forming a stable composite structure. The high electrical conductivity of carbon nanotubes and the copper matrix form a continuous conductive network, and at the same time, their dispersibility reduces electron scattering, improving the overall conductivity (≥94% IACS). As a nano-reinforcing phase, carbon nanotubes significantly improve the hardness (≥120 HV) and wear resistance of the alloy through the load transfer effect and pinning effect. The pre-dispersion design of the master alloy ensures the uniform distribution of carbon nanotubes during the subsequent copper alloy melting and casting process, avoiding agglomeration problems caused by direct addition. Summary: Through dispersion optimization, interface strengthening and composite structure design, this master alloy solves the dispersion problem of carbon nanotubes in the copper matrix, and at the same time realizes the synergistic improvement of electrical and mechanical properties, laying a foundation for the high performance of the final copper alloy.

[0012] In a second aspect, the present application provides a method for preparing a highly conductive and wear-resistant copper alloy, adopting the following technical solution: As a general technical concept, the present application also provides the method for preparing the above highly conductive and wear-resistant copper alloy, including the following steps: S61, Melting: Put copper, nickel, tin, and zinc into a vacuum induction furnace for melting, introduce argon for protection, with a melting temperature of 1250-1300 °C and keep warm for 20-30 minutes; S62, Refining: Add rare earth elements and the carbon nanotube-copper master alloy, introduce argon for protection, stir for 8-10 minutes, remove the slag, and obtain a molten alloy; S63, Casting: Pour the molten alloy into a water-cooled copper mold, with a cooling rate ≥80 °C / s, to obtain an ingot; S64, Heat treatment: Perform bell-jar heat treatment on the ingot to obtain ingot A; S65, After the ingot A is subjected to surface grinding treatment, it is successively subjected to rolling and aging treatment to obtain a highly conductive and wear-resistant copper alloy.

[0013] By adopting the above technical solutions, step S61: Melting: Copper, nickel, tin, and zinc are melted at high temperature and mixed evenly to prevent oxidation. Controlling the ratio of nickel and tin helps to form beneficial intermetallic compounds and improve performance. Step S62: Refining: Rare earth elements and carbon nanotube-copper master alloy are added, stirred evenly, and slag is removed. Rare earth purifies the grain boundaries, and carbon nanotubes enhance the dispersibility, jointly improving the electrical conductivity and strength. Step S63: Casting: The ingot is rapidly cooled to refine the grains. The rapid cooling is combined with subsequent heat treatment to refine the grains and homogenize the structure. Step S64: Solution treatment eliminates internal stress and makes the alloy structure more uniform. It provides a uniform initial structure for rolling and reduces processing defects. Step S65: Rolling and aging treatment: Rolling refines the grains and improves the strength; aging treatment further homogenizes the alloy and improves the wear resistance. The rolling and aging treatment work together to further improve the overall performance of the alloy. These steps cooperate with each other to jointly improve the electrical conductivity, wear resistance, and mechanical properties of the copper alloy.

[0014] Preferably, in step S63, the cooling rate is 90 - 100 °C / s.

[0015] By adopting the above technical solutions, a higher cooling rate (90 - 100 °C / s) further inhibits the grain growth during the solidification of the alloy, forming a finer nano / micro-scale grain structure. Grain refinement can improve the strength (through the Hall-Petch effect) and toughness of the alloy, while reducing electron scattering at grain boundaries, which is beneficial to maintaining high electrical conductivity (≥94% IACS). Rapid cooling shortens the residence time of the alloy melt in the high-temperature zone, reducing the risk of coarsening or segregation of Ni3Sn intermetallic compounds at grain boundaries, ensuring their uniform and dispersed distribution, and thus balancing electrical conductivity and wear resistance. The dispersion of the carbon nanotube-copper master alloy depends on rapid solidification to fix its position. A higher cooling rate can prevent the carbon nanotubes from re-aggregating due to gravity or convection during slow cooling, ensuring their effective combination with the copper matrix and strengthening the mechanical properties. The fine-grained structure formed by rapid cooling provides a uniform initial structure for the subsequent bell-type heat treatment, reducing the risk of compositional segregation during solution treatment, and at the same time avoiding the increase in energy consumption caused by the need for higher-temperature heat treatment due to grain coarsening. Fine-grained ingots are more likely to undergo uniform plastic deformation during rolling, reducing the crack tendency, and further improving the strength through dislocation multiplication; at the same time, the fine-grained matrix provides more nucleation sites for the uniform precipitation of the Ni3Sn phase during aging treatment, avoiding grain boundary weakening. After the rare earth elements (Ce / La) purify the grain boundaries, rapid cooling can further reduce the re-segregation of impurities at the grain boundaries, forming a "clean fine-grained" structure, reducing electron scattering, and synergistically ensuring high electrical conductivity. In summary, increasing the cooling rate to 90 - 100 °C / s forms a multi-scale synergy with the composition design (Ni / Sn ratio, rare earth, carbon nanotubes) and subsequent processes (heat treatment, rolling) through extreme grain refinement + inhibition of harmful phase segregation, ultimately achieving the synchronous optimization of electrical conductivity, hardness, and wear resistance, meeting the stringent requirements for the comprehensive performance of materials in scenarios such as power transmission and high-speed trains.

[0016] Preferably, in step S64, the process conditions of the bell-type heat treatment are: the atmosphere is a nitrogen atmosphere, and the gas flow rate of the nitrogen atmosphere is 15 - 20 m 3 / h; solution treatment is carried out at 800 - 850 °C for 1 - 2 hours, and then aging treatment is carried out at 400 - 450 °C for 5 - 6 hours.

[0017] By adopting the above technical solutions, nitrogen, as an inert protective gas, prevents the copper alloy from oxidizing at high temperatures (especially the carbon nanotubes and rare earth elements are prone to oxidation and failure), ensuring the cleanliness of the alloy surface. Flow control (15 - 20 m 3 / h) Ensure the dynamic update of the furnace atmosphere to avoid local oxygen residue or interference from impurity gases. Together with the argon protection in steps S61 / S62, a dual anti-oxidation system is formed to cover the entire process from melting to heat treatment, protecting the carbon nanotubes and rare earth functions from degradation. Solution treatment (800 - 850 °C, 1 - 2 h): High-temperature solution treatment allows elements such as nickel and tin to dissolve fully in the copper matrix, eliminating compositional segregation and internal stress caused by rapid cooling during casting (S63). The coarse Ni3Sn phase is dissolved, providing a uniform supersaturated solid solution for the subsequent nano-scale precipitation during aging. Together with the rapid cooling (≥80 °C / s) in S63, a "fine grain + homogenization" combination is formed: rapid cooling inhibits grain coarsening, and solution treatment eliminates micro-defects, jointly improving the matrix uniformity. Aging treatment (400 - 450 °C, 5 - 6 h): Medium-temperature aging promotes the uniform precipitation of the Ni3Sn phase at the nano-scale (instead of grain boundary segregation), reducing the negative impact of lattice distortion on conductivity. The precipitated phase serves as a second-phase strengthening particle, enhancing the hardness and wear resistance of the alloy (Vickers hardness ≥120 HV). Together with the subsequent rolling (S65), a "precipitation strengthening + work hardening" superposition effect is formed: the precipitated phase during aging hinders dislocation movement, and rolling further refines the grains, synergistically improving the balance of strength and toughness. In summary, the bell-jar heat treatment in step S64, through nitrogen anti-oxidation, solution homogenization, and aging precipitation regulation, becomes the core hub connecting casting (S63) and rolling (S65). The design of its process parameters not only optimizes the size and distribution of the Ni3Sn phase but also protects the functionality of carbon nanotubes and rare earths through atmosphere control, ultimately achieving a synergistic improvement in high conductivity (≥94% IACS) and high hardness (≥120 HV), meeting the demanding requirements for the comprehensive performance of materials in scenarios such as power transmission and high-speed trains.

[0018] Preferably, in step S65, the total deformation amount of the rolling is 10 - 20%, and the number of passes for the final rolling is 2 - 3 passes; the process parameters of the aging treatment are: the temperature is 160 °C, the time is 4 hours, the temperature is 180 °C, and the time is 8 hours.

[0019] In a third aspect, the present application provides an application of a high-conductivity and wear-resistant copper alloy, adopting the following technical solution: As a general technical concept, the present application also provides the above high-conductivity and wear-resistant copper alloy for power transmission busbars, high-speed train contact wires, or marine engineering corrosion-resistant connectors.

[0020] In summary, the beneficial technical effects of the present application are as follows: 1. Improve electrical conductivity: By regulating the mass ratio of nickel to tin, nano-scale intermetallic compound Ni3Sn is formed, reducing the influence of lattice distortion on conductivity. At the same time, the addition of rare earth elements purifies the grain boundaries, reduces electron scattering, and further improves the electrical conductivity of the alloy.

[0021] 2. Enhance wear resistance and creep resistance: The synergistic effect of nickel and tin improves the wear resistance and creep resistance of the alloy. Meanwhile, the use of carbon nanotube - copper master alloy enhances the mechanical properties and electrical conductivity of the alloy.

[0022] 3. Refine the grain structure: Adopt the method of rapid cooling to inhibit the formation of coarse grains and refine the grains. This helps to improve the strength and toughness of the alloy.

[0023] 4. Homogenize the alloy structure: Eliminate internal stress and composition segregation in the alloy ingot through solution treatment to make the alloy structure more uniform. Aging treatment prevents the segregation of Ni3Sn phase at grain boundaries and further homogenizes the alloy structure.

[0024] 5. Improve the comprehensive properties of the alloy: The comprehensive application of the above technical measures enables the finally prepared copper alloy material to have excellent electrical conductivity, wear resistance, and a balance of high strength and toughness.

[0025] 6. Wide application: The prepared high - conductivity wear - resistant copper alloy is suitable for key fields such as power transmission busbars, high - speed train catenary wires, or corrosion - resistant connectors for ocean engineering, and has important practical application value. Specific implementation manners

[0026] The following will describe the implementation scheme of the present application in detail in combination with embodiments. However, those skilled in the art will understand that the following embodiments are only used to illustrate the present application and should not be regarded as limiting the scope of the present application. For those not specified in the embodiments, the conventional conditions or the conditions recommended by the manufacturer are adopted. For the reagents or instruments not specified by the manufacturer, they are all conventional products that can be obtained through commercial purchase.

[0027] In the following examples, preparation examples, and preparation comparative examples, 1 part represents 100 g. The purity of the copper powder is 99.9%, and the particle size is 1 - 5 microns; the purities of copper, nickel, tin, zinc, lanthanum, and cerium are all 99.5%.

[0028] The preparation method of hydroxylated carbon nanotubes is as follows: Place 500 g of carbon nanotubes in 3 kg of sulfuric acid with a mass concentration of 60%, ultrasonically treat at 80 °C for 50 min, filter, wash with water 3 times, and dry to obtain hydroxylated carbon nanotubes.

[0029] Preparation Example 1 Preparation of carbon nanotube - copper master alloy The carbon nanotube - copper master alloy, by mass, includes the following preparation raw materials: 17 parts of hydroxylated carbon nanotubes, 800 parts of ethanol, 23 parts of copper ethanol, 23 parts of copper powder, 2.5 parts of hydroxybenzene ethanolamine, and 105 parts of tris - hydroxymethyl aminomethane hydrochloride solution with a pH of 7.3; The preparation method of the nanotube - copper master alloy includes the following steps: S51. Mix hydroxylated carbon nanotubes, hydroxybenzylethanolamine, and ethanol by mass fraction, and ultrasonically treat for 35 minutes to obtain a carbon nanotube dispersion; S52. Add cupric ethoxide, copper powder, and tris(hydroxymethyl)aminomethane hydrochloride solution to the carbon nanotube dispersion by mass fraction, stir evenly, then raise the temperature to 52 °C and react for 4 hours, concentrate to dryness, and collect the solid phase; S53. Calcinate the solid phase in a reducing atmosphere at 1215 °C for 3.8 hours, and cool to room temperature to obtain a carbon nanotube - copper intermediate alloy, wherein the reducing atmosphere is a mixed gas of argon and hydrogen, and the volume fraction of hydrogen is 13%.

[0030] Prepare Comparative Example 1 Mix 17 parts of hydroxylated carbon nanotubes and 32.6 parts of copper powder evenly to obtain a mixture; Example 1 A highly conductive and wear - resistant copper alloy, by mass percentage, includes the following preparation raw materials: nickel 3%, tin 5%, zinc: 1%, rare earth element: 0.1%, carbon nanotube - copper intermediate alloy 0.8%, and the balance is copper, wherein the rare earth element is lanthanum; The preparation method of the above - mentioned highly conductive and wear - resistant copper alloy includes the following steps: S61. Melting: Put copper, nickel, tin, and zinc into a vacuum induction furnace for melting according to the formula dosage, introduce argon for protection, the melting temperature is 1250 °C, and keep warm for 30 minutes; S62. Refining: Add rare earth elements and carbon nanotube - copper intermediate alloy according to the formula dosage, introduce argon for protection, stir for 8 minutes, remove the slag to obtain a molten alloy; S63. Casting: Pour the molten alloy into a water - cooled copper mold, and the cooling rate is 80 °C / s to obtain an ingot; S64. Heat treatment: Carry out bell - jar heat treatment on the ingot. The process conditions of the bell - jar heat treatment are: the atmosphere is a nitrogen atmosphere, and the gas flow rate of the nitrogen atmosphere is 15 m 3 / h; Solution treatment at 800 °C for 2 hours, and then aging treatment at 400 °C for 6 hours to obtain ingot A; S65. After surface grinding treatment of ingot A, carry out rolling and aging treatment in sequence. The total deformation amount of the rolling is 10%, and the number of passes of the finished rolling is 2 passes; the process parameters of the aging treatment are: the temperature is 160 °C, the time is 4 hours, the temperature is 180 °C, and the time is 8 hours to obtain a highly conductive and wear - resistant copper alloy.

[0031] Example 2 A highly conductive and wear-resistant copper alloy, by mass percentage, includes the following preparation raw materials: nickel 6%, tin 5%, zinc 3%, rare earth element: 0.3%, carbon nanotube-copper master alloy 1.2%, and the balance is copper, wherein the rare earth element is cerium; The preparation method of the above-mentioned highly conductive and wear-resistant copper alloy includes the following steps: S61. Melting: According to the formula dosage, put copper, nickel, tin, and zinc into a vacuum induction furnace for melting, introduce argon for protection, the melting temperature is 1300 °C, and keep warm for 30 minutes; S62. Refining: According to the formula dosage, add rare earth element and carbon nanotube-copper master alloy, introduce argon for protection, stir for 10 minutes, remove the slag, and obtain a molten alloy; S63. Casting: Pour the molten alloy into a water-cooled copper mold, and the cooling rate is 90 °C / s to obtain an ingot; S64. Heat treatment: Carry out bell-jar heat treatment on the ingot. The process conditions of the bell-jar heat treatment are: the atmosphere is a nitrogen atmosphere, and the gas flow rate of the nitrogen atmosphere is 20 m 3 / h; solution treatment at 850 °C for 1 hour, and then aging treatment at 450 °C for 5 hours to obtain ingot A; S65. After the ingot A is subjected to surface grinding treatment, rolling and aging treatment are carried out in sequence. The total deformation amount of the rolling is 20%, and the number of passes of the finished rolling is 3 passes; the process parameters of the aging treatment are: the temperature is 160 °C, the time is 4 hours, the temperature is 180 °C, and the time is 8 hours to obtain a highly conductive and wear-resistant copper alloy.

[0032] Example 3 A highly conductive and wear-resistant copper alloy, by mass percentage, includes the following preparation raw materials: nickel 4.5%, tin 3%, zinc: 2%, rare earth element: 0.25%, carbon nanotube-copper master alloy 1%, and the balance is copper, wherein the rare earth element is cerium; The preparation method of the above-mentioned highly conductive and wear-resistant copper alloy includes the following steps: S61. Melting: According to the formula dosage, put copper, nickel, tin, and zinc into a vacuum induction furnace for melting, introduce argon for protection, the melting temperature is 1280 °C, and keep warm for 25 minutes; S62. Refining: According to the formula dosage, add rare earth element and carbon nanotube-copper master alloy, introduce argon for protection, stir for 9 minutes, remove the slag, and obtain a molten alloy; S63. Casting: Pour the molten alloy into a water-cooled copper mold, and the cooling rate is 100 °C / s to obtain an ingot; S64. Heat treatment: Carry out bell-jar heat treatment on the ingot. The process conditions of the bell-jar heat treatment are: the atmosphere is a nitrogen atmosphere, and the gas flow rate of the nitrogen atmosphere is 18 m 3 / h; Solution treatment at 830°C for 1.5 hours, followed by aging treatment at 430°C for 5.6 hours to obtain ingot A; S65. After the surface of ingot A is polished, rolling and aging treatments are carried out in sequence. The total deformation amount of the rolling is 15%, and the number of passes of the finished rolling is 2 passes; the process parameters of the aging treatment are: temperature is 160°C, time is 4 hours, temperature is 180°C, time is 8 hours, to obtain a high-conductivity wear-resistant copper alloy.

[0033] Comparative Example 1 Same as Example 3, except that nickel is 7.5% and tin is 0%.

[0034] Comparative Example 2 Same as Example 3, except that nickel is 0% and tin is 7.5%.

[0035] Comparative Example 3 Same as Example 3, except that the rare earth element cerium is 0%.

[0036] Comparative Example 4 Same as Example 3, except that an equivalent amount of the mixture prepared in Comparative Example 1 is used to replace the carbon nanotube - copper master alloy.

[0037] Comparative Example 5 Same as Example 3, except that in S64, heat treatment: the ingot is subjected to bell jar heat treatment, and the process conditions of the bell jar heat treatment are: the atmosphere is a nitrogen atmosphere, and the gas flow rate of the nitrogen atmosphere is 18m 3 / h; Solution treatment at 830°C for 1.5 hours to obtain ingot A.

[0038] Comparative Example 6 Same as Example 3, except that in S64, heat treatment: the ingot is subjected to bell jar heat treatment, and the process conditions of the bell jar heat treatment are: the atmosphere is a nitrogen atmosphere, and the gas flow rate of the nitrogen atmosphere is 18m 3 / h; Aging treatment at 430°C for 5.6 hours to obtain ingot A.

[0039] Performance Test Samples of the high-conductivity wear-resistant copper alloys prepared in Example 1, Example 3, and Comparative Examples 1 - 6 are taken for the following performance tests; The test method for tensile strength is: GB / T 34505 - 2017 Room Temperature Tensile Test Method; The test method for elongation is: GB / T 22834505 - 2017 Room Temperature Tensile Test Method; Conductivity: The conductivity of the copper alloy is expressed in units of the International Annealed Copper Standard (%IACS); The test method for hardness is: GB / T 4340.1-2009 Metallic materials - Vickers hardness test method; Wear resistance: Tested according to ASTM G65 standard (under dry friction conditions, load 50N, rotation speed 200rpm).

[0040] Table 1 Performance test Analyzing the data in Table 1, it can be seen that: 1) The highly conductive and wear-resistant copper alloys prepared in Examples 1 - 3 have excellent electrical conductivity, wear resistance, and a balance of high strength and toughness, and are suitable for applications such as power transmission busbars, high-speed train contact wires, or corrosion-resistant connectors for ocean engineering.

[0041] 2) Combining the performance comparative analysis of the highly conductive and wear-resistant copper alloys prepared in Example 3 and Comparative Examples 1 - 2 shows that the mass ratio of nickel to tin is 1.5:1, and the two cooperate to form nanoscale intermetallic compounds (Ni3Sn), improving the wear resistance and creep resistance of the alloy. At the same time, due to their nanoscale size, they can effectively reduce the negative impact on electrical conductivity, ensuring that the alloy has high electrical conductivity. This ratio enhances the mechanical properties of the alloy by forming nanoscale hard phases while maintaining its excellent electrical conductivity.

[0042] 3) Combining the performance comparative analysis of the highly conductive and wear-resistant copper alloys obtained in Example 3 and Comparative Example 3 shows that adding rare earth element Ce reacts with impurities such as oxygen and sulfur to form high-melting-point compounds (such as Ce2O3), reducing grain boundary impurity segregation, reducing electron scattering, and improving electrical conductivity. Rare earth element Ce inhibits grain growth, hinders grain boundary migration by adsorbing at grain boundaries, refines the grain size, and improves the strength and toughness of the alloy. Rare earth element Ce can also be combined with the dispersion strengthening of Ni3Sn to further optimize the grain boundary structure, reduce defects, and improve the comprehensive performance.

[0043] 4) Combining the performance comparative analysis of the highly conductive and wear-resistant copper alloys prepared in Example 3 and Comparative Example 4 shows that the carbon nanotube - copper master alloy prepared in this application utilizes the hydroxyl functional groups on the surface of hydroxylated carbon nanotubes, and uses hydroxybenzene ethanolamine to perform nitrogen modification on the carbon nanotubes. Through nitrogen-containing groups and hydroxyl-containing groups, copper elements and copper powder are fully dispersed, and a carbon nanotube - copper master alloy with a smaller particle size is prepared; thereby further improving the dispersion of carbon nanotubes in the finally prepared copper alloy material, strengthening the effective combination of carbon nanotubes and copper alloy, and significantly improving the electrical conductivity, wear resistance, high strength, and toughness of the copper alloy material.

[0044] 5) Comparative analysis of the properties of the highly conductive and wear-resistant copper alloy prepared by combining Example 3 and Comparative Examples 5-6 shows that in step S64, solution treatment and aging treatment are adopted, and by virtue of their combined action, high-temperature solution treatment enables elements such as nickel and tin to be fully dissolved in the copper matrix, eliminating composition segregation and internal stress caused by rapid cooling during casting (S63). The coarse Ni3Sn phase is dissolved, providing a uniform supersaturated solid solution for the subsequent precipitation at the nanoscale during aging. It forms a "fine grain + homogenization" combination with the rapid cooling in S63: rapid cooling inhibits grain coarsening, and solution treatment eliminates microdefects, jointly improving the matrix uniformity. Medium-temperature aging promotes the uniform precipitation of the Ni3Sn phase at the nanoscale (instead of grain boundary segregation), reducing the negative impact of lattice distortion on conductivity. The precipitated phase serves as the second-phase strengthening particles, enhancing the hardness and wear resistance of the alloy. It forms a superposition effect of "precipitation strengthening + work hardening" with the subsequent rolling (S65): the precipitated phase during aging hinders the movement of dislocations, and rolling further refines the grains, synergistically improving the balance of strength and toughness.

[0045] The above embodiments are only used to explain the technical solutions of the present application and not to limit them. Although the above embodiments have specifically described the present application, those skilled in the art should understand that the specific implementation manners of the present invention can still be modified or equivalently replaced. Any modification and equivalent replacement without departing from the spirit and scope of the present application shall be covered by the protection scope of the present application.

Claims

1. A highly conductive and wear-resistant copper alloy, characterized in that: The preparation raw materials include, by mass percentage, 3-6% nickel, 2-5% tin, 1-3% zinc, 0.1-0.5% rare earth elements, 0.8-1.2% carbon nanotube-copper master alloy, and the balance is copper, wherein the rare earth element is one of cerium and lanthanum, and the electrical conductivity of the high-conductivity and wear-resistant copper alloy is ≥94% IACS, and the Vickers hardness is ≥120 HV.

2. A highly conductive and wear-resistant copper alloy according to claim 1, characterized in that: The mass ratio of nickel to tin is (1.2-1.5):1, and the two synergistically form a nano-scale intermetallic compound (Ni3Sn), which improves the wear resistance and creep resistance of the alloy.

3. The highly conductive and wear-resistant copper alloy according to claim 1, characterized in that: The rare earth element is cerium, and the addition amount is 0.2-0.3%, which is used to refine the grains.

4. The highly conductive and wear-resistant copper alloy according to claim 1, characterized in that: The carbon nanotube-copper master alloy comprises the following raw materials by weight: 15-18 parts of hydroxylated carbon nanotubes, 800 parts of ethanol, 20-25 parts of ethanol copper, 20-25 parts of copper powder, 2-3 parts of hydroxyphenylethanolamine and 100-110 parts of tris(hydroxymethyl)aminomethane hydrochloride solution with a pH of 7.

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5. A highly conductive and wear-resistant copper alloy according to claim 4, characterized in that: The method for preparing the carbon nanotube-copper master alloy comprises the following steps: S51, mixing hydroxylated carbon nanotubes, hydroxyphenylethanolamine and ethanol according to their weight fractions, and ultrasonically treating for 30-40 minutes to obtain a carbon nanotube dispersion; S52, adding ethanol copper, copper powder and tris(hydroxymethyl)aminomethane hydrochloride solution to the carbon nanotube dispersion according to their weight fractions, stirring evenly, heating to 52° C. to react for 4 hours, concentrating to dryness, and collecting the solid phase; S53, calcining the solid phase in a reducing atmosphere at 1210-1220° C. for 3.5-4 hours, and cooling to room temperature to obtain a carbon nanotube-copper master alloy, wherein the reducing atmosphere is a mixed gas of argon and hydrogen, and the volume fraction of hydrogen is 12-15%.

6. A method for preparing the highly conductive and wear-resistant copper alloy according to any one of claims 1 to 5, characterized in that: The following steps are involved: S61, smelting: put copper, nickel, tin and zinc into a vacuum induction furnace for smelting, pass argon gas for protection, the smelting temperature is 1250-1300℃, and keep warm for 20-30 minutes; S62, refining: adding rare earth elements and carbon nanotube-copper master alloy, passing argon gas for protection, stirring for 8-10 minutes, removing slag, and obtaining a molten alloy; S63, casting: pouring the molten alloy into a water-cooled copper mold at a cooling rate of ≥80°C / s to obtain an ingot; S64, heat treatment: performing bell-type heat treatment on the ingot to obtain ingot A; S65. After surface grinding treatment of ingot A, rolling and aging treatment are performed in sequence to obtain a highly conductive and wear-resistant copper alloy.

7. The method for preparing a highly conductive and wear-resistant copper alloy according to claim 6, characterized in that: In step S63, the cooling rate is 90-100°C / s.

8. The method for preparing a highly conductive and wear-resistant copper alloy according to claim 6, characterized in that: In step S64, the process conditions of the bell-type heat treatment are: the atmosphere is a nitrogen atmosphere, and the gas flow rate of the nitrogen atmosphere is 15-20m 3 / h; solution treatment at 800-850℃ for 1-2 hours, followed by aging treatment at 400-450℃ for 5-6 hours.

9. The method for preparing a highly conductive and wear-resistant copper alloy according to claim 6, characterized in that: In step S65, the total deformation of the rolling is 10-20%, and the number of passes of the finished product rolling is 2-3 passes; the process parameters of the aging treatment are: temperature of 160°C, time of 4 hours, temperature of 180°C, time of 8 hours.

10. An application of the high-conductivity and wear-resistant copper alloy according to any one of claims 1 to 4, characterized in that: Used for power transmission busbars, high-speed train contact wires or corrosion-resistant connectors for marine engineering.

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