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

Abstract

The application relates to the technical field of copper alloy, 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 the following preparation raw materials in percentage by mass: 3-6% of nickel, 2-5% of tin, 1-3% of zinc, 0.1-0.5% of rare earth elements, 0.8-1.2% of carbon nanotube-copper intermediate alloy, and the balance of copper, wherein the rare earth elements are one of cerium and lanthanum, the conductivity of the high-conductivity wear-resistant copper alloy is greater than or equal to 94% IACS, and the Vickers hardness is greater than or equal to 120 HV.The application remarkably improves the conductivity, wear resistance and mechanical properties of the copper alloy material by regulating the mass ratio of nickel (Ni) and tin (Sn), adding rare earth elements and carbon nanotube-copper intermediate alloy and precisely controlling the preparation process, so that the copper alloy material has a wide application prospect in the fields of power transmission, high-speed transportation and ocean engineering.

Description

TECHNICAL FIELD

[0001] The application 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. BACKGROUND

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

[0003] The application aims at the deficiencies of the current technology and provides a high-conductivity wear-resistant copper alloy and a preparation method and application thereof. The mass ratio of nickel (Ni) and tin (Sn) is regulated, the nanoscale intermetallic compound (Ni3Sn) is formed by the cooperation of the two, the influence of lattice distortion on conductivity is reduced, the wear resistance and creep resistance of the alloy are improved, the grain boundary is purified by adding a rare earth element, the electron scattering is reduced, the conductivity and toughness are improved, the copper element and copper powder are fully dispersed by the hydroxyl functional groups on the surface of the carbon nanotubes and the nitrogen modification of the carbon nanotubes by hydroxyphenylethanolamine, the carbon nanotube-copper intermediate alloy with small particle size is prepared, the dispersibility of the carbon nanotubes in the finally prepared copper alloy material is further improved, the carbon nanotubes and the copper alloy are effectively combined, and the mechanical properties and the conductivity of the copper alloy material are significantly improved. The high-conductivity wear-resistant copper alloy prepared by the application has excellent conductivity, wear resistance, high strength and toughness balance, and is suitable for application in power transmission busbars, high-speed train contact wires or marine engineering corrosion-resistant connectors.

[0004] In the first aspect, the application provides a high-conductivity wear-resistant copper alloy, which adopts the following technical scheme:

[0005] A high-conductivity wear-resistant copper alloy, which comprises the following preparation raw materials in percentage 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 being copper, wherein the rare earth element is one of cerium and lanthanum, the conductivity of the high-conductivity wear-resistant copper alloy is greater than or equal to 94% IACS (international annealed copper standard), and the Vickers hardness is greater than or equal to 120 HV.

[0006] By adopting the above technical scheme, 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) can easily cause lattice distortion, increase electron scattering, and reduce electrical conductivity. However, Ni3Sn is uniformly precipitated in the form of nanoparticles, avoiding excessive interference with the copper matrix lattice, thereby strengthening the alloy while maintaining high electrical conductivity (≥94% IACS). The optimized ratio of Ni to Sn ensures the uniform distribution of Ni3Sn phase in the matrix, which not only serves 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, making it 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 improves the strength of the matrix, and enhances the oxidation resistance of the alloy. The content of Zn is controlled within 1-3%, avoiding excessive content leading to significant decrease in electrical conductivity (the electrical resistivity of Zn is higher than that of Cu), balancing the strength and electrical conductivity requirements. 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 improving electrical conductivity. Rare earth elements inhibit grain growth by adsorbing on grain boundaries to hinder grain boundary migration, refining 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 the overall performance. The role of carbon nanotube-copper intermediate alloy (0.8-1.2%), dispersion enhancement and conductive network construction: through hydroxyphenethyl alcohol amine, carbon nanotubes (CNTs) are nitrogen-doped, introducing nitrogen-containing groups (such as amino groups), enhancing the interfacial bonding force between CNTs and the copper matrix, and improving the dispersibility of CNTs in copper powder using hydroxyl functional groups. The modified CNTs and copper powder are pre-dispersed by melting method to form a carbon nanotube-copper intermediate alloy with smaller particle size, avoiding CNTs agglomeration in the final alloy, and ensuring uniform distribution. The high strength and high electrical conductivity (1D electron transport channel) of CNTs combined with the copper matrix form a three-dimensional conductive network, while the "pinning effect" hinders dislocation movement, significantly improving the mechanical properties (hardness ≥120HV) and electrical conductivity of the alloy. The role of copper (balance) as a matrix, the copper matrix provides high electrical conductivity (pure copper conductivity 100% IACS), and the optimized design of other elements ensures minimal loss of electrical conductivity. The ductility of copper provides a basis for the toughness of the alloy, and together with other strengthening phases (Ni3Sn, CNTs), it realizes the balance of "high strength-high toughness". Ni3Sn phase and CNTs together as dispersion strengthening phase, respectively through chemical bonding and physical pinning effect to improve wear resistance and strength, while the conductive network of CNTs compensates for the slight impact of Ni3Sn on electrical conductivity.The rare earth elements purify the grain boundaries, reduce electron scattering, and improve the electrical conductivity and mechanical properties together with fine-grain strengthening (rapid cooling process). In summary, the copper alloy realizes the synergistic improvement of high electrical conductivity (≥94% IACS), high hardness (≥120 HV), and wear resistance by adjusting the Ni-Sn ratio, purifying the grain boundaries with rare earth, dispersing and strengthening with CNTs, and optimizing the process, which is suitable for power transmission busbars, high-speed train contact wires, or marine engineering corrosion-resistant connectors.

[0007] Preferably, the mass ratio of nickel to tin is (1.2-1.5):1, and the two together form nanoscale intermetallic compounds (Ni3Sn) to improve the wear resistance and creep resistance of the alloy.

[0008] By adopting the above technical solution, the mass ratio of nickel (Ni) to tin (Sn) is controlled at 1.2-1.5:1, which mainly promotes the formation of nanoscale intermetallic compound Ni3Sn in the high-conductivity wear-resistant copper alloy. This compound can improve the wear resistance and creep resistance of the alloy, and due to its nanoscale size, it can also 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.

[0009] Preferably, the rare earth element is cerium, and the addition amount is 0.2-0.3%, which is used to refine the grains.

[0010] Preferably, the carbon nanotube-copper intermediate alloy comprises the following preparation raw materials in mass fraction: hydroxylated carbon nanotubes 15-18 parts, ethanol 800 parts, copper ethoxide 20-25 parts, copper powder 20-25 parts, hydroxyphenylethanolamine 2-3 parts, and a tris-hydroxymethyl aminomethane hydrochloride solution with a pH of 7.3 100-110 parts.

[0011] Preferably, the preparation method of the carbon nanotube-copper intermediate alloy comprises the following steps:

[0012] S51, according to the mass fraction, mix hydroxylated carbon nanotubes, hydroxyphenylethanolamine, and ethanol, and ultrasonically treat for 30-40 minutes to prepare a carbon nanotube dispersion;

[0013] S52, according to the mass fraction, add copper ethoxide, copper powder, and a tris-hydroxymethyl aminomethane hydrochloride solution to the carbon nanotube dispersion, stir until uniform, then heat to 52°C and react for 4 hours, concentrate to dryness, and collect the solid phase;

[0014] S53, calcine the solid phase in a reducing atmosphere at 1210-1220°C for 3.5-4 hours, and cool to room temperature to obtain a carbon nanotube-copper intermediate alloy, wherein the reducing atmosphere is a mixture of argon and hydrogen, and the volume fraction of hydrogen is 12-15%.

[0015] By adopting the technical scheme, hydroxyphenylethanolamine reacts with the hydroxyl group on the surface of the carbon nanotube through the amino group to form a nitrogen-doped structure, thereby enhancing the dispersibility and interface bonding force, and the ultrasonic treatment (S51) is adopted to realize the uniform dispersion of the carbon nanotube; the Tris-HCl buffer solution regulates the reaction environment: the trimethylaminomethane hydrochloride solution with a pH of 7.3 provides a stable alkaline environment, promotes the hydrolysis of copper ethoxide (Cu(OEt)2) into copper nanoparticles, and cooperates with copper powder to be uniformly coated on the surface of the carbon nanotube (S52). The carbon nanotube-copper composite structure is constructed: the decomposition of copper ethoxide provides high-activity copper nanoparticles, which cooperates with copper powder to form a copper matrix and is closely combined with the carbon nanotube through chemical bonding to reduce the interface defects. High-temperature reduction calcination (S53): in an argon-hydrogen mixed atmosphere (H2 accounts for 12-15%), hydrogen reduces copper oxide and cleans the surface of the carbon nanotube to enhance the interface bonding; high temperature of 1210-1220℃ promotes the metallurgical bonding of the carbon nanotube and the copper matrix to form a stable composite structure. The high conductivity of the carbon nanotube forms a continuous conductive network with the copper matrix, and its dispersibility reduces electron scattering to improve the overall conductivity (≥94% IACS). The carbon nanotube acts as a nano-reinforcing phase to significantly improve the hardness (≥120HV) and wear resistance of the alloy through the load transfer effect and pinning effect. The pre-dispersion design of the intermediate alloy ensures the uniform distribution of the carbon nanotube in the subsequent copper alloy melting and casting process, avoiding the agglomeration problem caused by direct addition. Summary: The intermediate alloy solves the dispersion problem of the carbon nanotube in the copper matrix through dispersion optimization, interface strengthening and composite structure design, and realizes the synergistic improvement of the conductivity and mechanical properties, laying a foundation for the high performance of the final copper alloy.

[0016] In the second aspect, the application provides a preparation method of a high-conductivity wear-resistant copper alloy, which adopts the following technical scheme: as a general technical concept, the application also provides the preparation method of the high-conductivity wear-resistant copper alloy, which comprises the following steps:

[0017] S61, melting: placing copper, nickel, tin and zinc into a vacuum induction furnace for melting, and introducing argon protection, the melting temperature is 1250-1300℃, and the holding time is 20-30 minutes;

[0018] S62, refining: adding rare earth elements and carbon nanotube-copper intermediate alloy, introducing argon protection, stirring for 8-10 minutes, and removing the slag to obtain a molten alloy;

[0019] S63, casting: pouring the molten alloy into a water-cooled copper mold, and cooling at a rate of ≥80℃ / s to obtain an ingot;

[0020] S64, heat treatment: performing bell-type heat treatment on the ingot to obtain an ingot A;

[0021] S65, after surface polishing treatment of the ingot A, rolling and aging treatment are sequentially performed to obtain the high-conductivity wear-resistant copper alloy.

[0022] By adopting the above technical scheme, step S61: melting: copper, nickel, tin, zinc are melted and mixed uniformly at high temperature to prevent oxidation. Controlling the proportion of nickel and tin helps to form beneficial intermetallic compounds and improve performance. Step S62: refining: adding rare earth elements and carbon nanotube-copper intermediate alloy, stirring uniformly and removing slag. Rare earth purifies the grain boundary, and carbon nanotube enhances the dispersibility, which improves the electrical conductivity and strength together. Step S63: casting: rapid cooling of the ingot, refining the grain. Rapid cooling cooperates with subsequent heat treatment to refine the grain and homogenize the structure. Step S64: solid solution treatment eliminates internal stress, making the alloy structure more uniform. Providing a uniform initial structure for rolling, reducing processing defects. Step S65: rolling and aging treatment: rolling refines the grain and improves the strength; aging treatment makes the alloy further homogenized and improves the wear resistance. Rolling and aging treatment work together to further improve the overall performance of the alloy. These steps cooperate with each other to improve the electrical conductivity, wear resistance and mechanical properties of the copper alloy.

[0023] Preferably, in step S63, the cooling rate is 90-100℃ / s.

[0024] By adopting the above technical scheme, a higher cooling rate (90-100℃ / s) further inhibits the grain growth during solidification of the alloy, forming a finer nano / sub-micron grain structure. Grain refinement can improve the strength (through the Hall-Petch effect) and toughness of the alloy, while reducing electron scattering at the grain boundary, which is conducive 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 the grain boundary, ensuring their uniform dispersion, thereby balancing electrical conductivity and wear resistance. The dispersibility of carbon nanotube-copper intermediate alloy depends on the rapid solidification to fix its position. Higher cooling rate can prevent carbon nanotubes from re-aggregating due to gravity or convection in slow cooling, ensuring their effective combination with the copper matrix and strengthening mechanical properties. The fine-grained structure formed by rapid cooling provides a uniform initial structure for subsequent bell-type heat treatment, reducing the risk of composition segregation during solid solution treatment, while avoiding the increase in energy consumption caused by higher temperature heat treatment due to grain coarsening. Fine-grained ingots are more prone to uniform plastic deformation during rolling, reducing the tendency to crack, and further improving strength through dislocation multiplication; at the same time, the fine-grained matrix provides more nucleation sites for the uniform precipitation of Ni3Sn phase during aging treatment, avoiding grain boundary weakening. After purifying the grain boundary with rare earth elements (Ce / La), rapid cooling can further reduce the re-segregation of impurities at the grain boundary, forming a "clean fine-grained" structure, reducing electron scattering, and synergistically ensuring high electrical conductivity. In summary, the increase in cooling rate to 90-100℃ / s through extreme grain refinement + inhibition of harmful phase segregation, combined with composition design (Ni / Sn ratio, rare earth, carbon nanotubes) and subsequent processes (heat treatment, rolling), forms a multi-scale synergy, ultimately achieving simultaneous optimization of electrical conductivity, hardness, and wear resistance, meeting the stringent requirements of power transmission, high-speed trains, and other scenarios for material comprehensive performance.

[0025] Preferably, in step S64, the process conditions of the bell-type heat treatment are: the atmosphere is a nitrogen atmosphere, the gas flow of the nitrogen atmosphere is 15-20m 3 / h; solid solution treatment at 800-850℃ for 1-2 hours, followed by aging treatment at 400-450℃ for 5-6 hours.

[0026] By adopting the above technical scheme, nitrogen gas as an inert protective gas prevents oxidation of the copper alloy at high temperatures (especially carbon nanotubes and rare earth elements are prone to oxidation failure), ensuring a clean alloy surface. Flow control (15-20m 3h) Ensure the dynamic update of the atmosphere in the furnace, avoid local oxygen residues or impurity gas interference. Form a double anti-oxidation system with the argon protection of steps S61 / S62, cover the whole process from smelting to heat treatment, protect the carbon nanotubes and rare earth functions from degradation. Solution treatment (800-850℃, 1-2h): high-temperature solid solution makes nickel, tin and other elements fully dissolve in the copper matrix, eliminating the composition segregation and internal stress caused by rapid cooling (S63). Dissolve coarse Ni3Sn phase, provide uniform supersaturated solid solution for subsequent aging of nanoscale precipitation. Form a combination of "fine grain + homogenization" with the rapid cooling (≥80℃ / s) of S63: rapid cooling inhibits grain coarsening, and solid solution treatment eliminates micro defects, together improving the uniformity of the matrix. Aging treatment (400-450℃, 5-6h): medium-temperature aging promotes the uniform precipitation of Ni3Sn phase at the nanoscale (rather than grain boundary segregation), reducing the negative impact of lattice distortion on electrical conductivity. The precipitated phase as a second phase strengthening particle, improves the hardness and wear resistance of the alloy (Vickers hardness ≥120HV). With subsequent rolling (S65), the "precipitation strengthening + work hardening" superposition effect is formed: aging precipitates hinder dislocation movement, and rolling further refines the grains, synergistically improving the strength and toughness balance. In summary, the bell jar heat treatment of step S64, through nitrogen anti-oxidation, solid solution homogenization and aging precipitation control, becomes the core link connecting casting (S63) and rolling (S65). The design of its process parameters not only optimizes the size and distribution of Ni3Sn phase, but also protects the functionality of carbon nanotubes and rare earths through atmosphere control, ultimately achieving a synergistic improvement in high electrical conductivity (≥94% IACS) and high hardness (≥120HV), meeting the stringent demands of power transmission, high-speed trains and other scenarios for comprehensive material performance.

[0027] Preferably, in step S65, the total deformation of the rolling is 10-20%, and the finished rolling is 2-3 passes; the process parameters of the aging treatment are: temperature 160℃, time 4 hours, temperature 180℃, time 8 hours.

[0028] In a third aspect, the application provides an application of the high-conductivity wear-resistant copper alloy, which adopts the following technical scheme:

[0029] As a general technical concept, the application also provides the use of the above high-conductivity wear-resistant copper alloy for power transmission busbars, high-speed train contact wires, or marine engineering corrosion-resistant connectors.

[0030] In summary, the application has the following beneficial technical effects:

[0031] 1. Improve the electrical conductivity: by adjusting the mass ratio of nickel and tin, form nanoscale intermetallic compound Ni3Sn, reduce the influence of lattice distortion on electrical conductivity. At the same time, the addition of rare earth elements purifies the grain boundary, reduces electron scattering, and further improves the electrical conductivity of the alloy.

[0032] 2. Enhanced wear resistance and creep resistance: The synergistic effect of nickel and tin improves the wear resistance and creep resistance of the alloy. At the same time, the use of carbon nanotube-copper interalloy enhances the mechanical properties and electrical conductivity of the alloy.

[0033] 3. Refinement of grain structure: The method of rapid cooling inhibits the formation of coarse grains and refines the grain structure. This helps to improve the strength and toughness of the alloy.

[0034] 4. Uniform alloy organization: The internal stress and composition segregation in the alloy ingot are eliminated by solid solution treatment, making the alloy organization more uniform. Aging treatment prevents the segregation of Ni3Sn phase at the grain boundary, further homogenizing the alloy organization.

[0035] 5. Improved comprehensive performance of the alloy: The comprehensive application of the above technical measures makes the finally prepared copper alloy material have excellent electrical conductivity, wear resistance, and balance of high strength and toughness.

[0036] 6. Wide application: The prepared high-conductivity wear-resistant copper alloy is suitable for application in key fields such as power transmission busbar, high-speed train contact line, or marine engineering corrosion-resistant connector, and has important practical application value. DETAILED DESCRIPTION

[0037] The embodiments of the present application will be described in detail below with reference to examples, but those skilled in the art will understand that the following examples are only for illustration of the present application and should not be regarded as limiting the scope of the present application. If the specific conditions are not specified in the examples, the conventional conditions or the conditions recommended by the manufacturer are used. If the manufacturer of the reagent or instrument is not specified, it is a conventional product that can be purchased on the market.

[0038] 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 purity of copper, nickel, tin, zinc, lanthanum, and cerium is 99.5%.

[0039] The preparation method of hydroxylated carbon nanotubes is as follows: 500 g of carbon nanotubes is placed in 3 kg of 60% mass concentration sulfuric acid, ultrasonically treated at 80°C for 50 min, filtered, and washed with water for 3 times, and dried to obtain hydroxylated carbon nanotubes.

[0040] Preparation Example 1: Preparation of carbon nanotube-copper interalloy

[0041] The carbon nanotube-copper interalloy includes the following preparation raw materials in parts by mass: hydroxylated carbon nanotubes 17 parts, ethanol 800 parts, copper ethoxide 23 parts, copper powder 23 parts, hydroxyphenethylamine 2.5 parts, and 105 parts of a tris-hydroxymethyl aminomethane hydrochloride solution with a pH of 7.3;

[0042] A preparation method of a carbon nanotube-copper intermediate alloy comprises the following steps:

[0043] S51, according to mass fraction, hydroxylated carbon nanotubes, hydroxyphenyl ethanolamine and ethanol are mixed, and ultrasonic treatment is performed for 35 minutes to obtain a carbon nanotube dispersion;

[0044] S52, according to mass fraction, copper ethoxide, copper powder and a solution of tris-hydroxymethyl aminomethane hydrochloride are added to the carbon nanotube dispersion, stirred uniformly, then heated to 52 DEG C and reacted for 4 hours, concentrated to dryness, and the solid phase is collected;

[0045] S53, the solid phase is calcined in a reducing atmosphere at 1215 DEG C for 3.8 hours, and then cooled 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%.

[0046] Preparation Example 1

[0047] Hydroxylated carbon nanotubes 17 parts and copper powder 32.6 parts are mixed uniformly to obtain a mixture;

[0048] Example 1

[0049] A high-conductivity wear-resistant copper alloy comprises, by mass percentage, the following preparation raw materials: nickel 3%, tin 5%, zinc 1%, rare earth elements 0.1%, carbon nanotube-copper intermediate alloy 0.8%, and the balance being copper, wherein the rare earth elements are lanthanum;

[0050] A preparation method of the above high-conductivity wear-resistant copper alloy comprises the following steps:

[0051] S61, melting: according to the formula amount, copper, nickel, tin and zinc are put into a vacuum induction furnace for melting, argon is introduced for protection, the melting temperature is 1250 DEG C, and the holding time is 30 minutes;

[0052] S62, refining: according to the formula amount, rare earth elements and carbon nanotube-copper intermediate alloy are added, argon is introduced for protection, and stirring is performed for 8 minutes to remove the slag, thereby obtaining a molten alloy;

[0053] S63, casting: the molten alloy is poured into a water-cooled copper mold, the cooling rate is 80 DEG C / s, and a cast ingot is obtained;

[0054] S64, heat treatment: the cast ingot is subjected to bell-type heat treatment, the process conditions of the bell-type heat treatment are as follows: the atmosphere is a nitrogen atmosphere, the gas flow of the nitrogen atmosphere is 15 m 3 / h, solid solution treatment is performed at 800 DEG C for 2 hours, and then aging treatment is performed at 400 DEG C for 6 hours, thereby obtaining a cast ingot A;

[0055] S65, after surface grinding treatment of the ingot A, sequentially rolling and aging treatment, the total deformation of the rolling is 10%, the pass of the finished product rolling is 2 passes; the process parameters of the aging treatment are: the temperature is 160 DEG C, the time is 4 hours, the temperature is 180 DEG C, the time is 8 hours, and the high-conductivity wear-resistant copper alloy is obtained.

[0056] Example 2

[0057] A high-conductivity wear-resistant copper alloy, by mass percent, comprises the following preparation raw materials: nickel 6%, tin 5%, zinc 3%, rare earth elements: 0.3%, carbon nanotube-copper intermediate alloy 1.2%, and the balance is copper, wherein the rare earth elements are cerium;

[0058] The preparation method of the above high-conductivity wear-resistant copper alloy comprises the following steps:

[0059] S61, melting: according to the formula amount, copper, nickel, tin and zinc are put into a vacuum induction furnace for melting, argon is introduced for protection, the melting temperature is 1300 DEG C, and the temperature is kept for 30 minutes;

[0060] S62, refining: according to the formula amount, rare earth elements and carbon nanotube-copper intermediate alloy are added, argon is introduced for protection, stirring is carried out for 10 minutes, and slag is removed to obtain molten alloy;

[0061] S63, casting: the molten alloy is poured into a water-cooled copper mold, the cooling rate is 90 DEG C / s, and the ingot is obtained;

[0062] S64, heat treatment: the ingot is subjected to bell jar heat treatment, the process conditions of the bell jar heat treatment are: the atmosphere is nitrogen atmosphere, the gas flow of the nitrogen atmosphere is 20 m 3 / h; solid solution treatment at 850 DEG C for 1 hour, and then aging treatment at 450 DEG C for 5 hours, to obtain ingot A;

[0063] S65, after surface grinding treatment of the ingot A, sequentially rolling and aging treatment, the total deformation of the rolling is 10%, the pass of the finished product rolling is 2 passes; the process parameters of the aging treatment are: the temperature is 160 DEG C, the time is 4 hours, the temperature is 180 DEG C, the time is 8 hours, and the high-conductivity wear-resistant copper alloy is obtained.

[0064] Example 3

[0065] A high-conductivity wear-resistant copper alloy, by mass percent, comprises the following preparation raw materials: nickel 4.5%, tin 3%, zinc: 2%, rare earth elements: 0.25%, carbon nanotube-copper intermediate alloy 1%, and the balance is copper, wherein the rare earth elements are cerium;

[0066] The preparation method of the above high-conductivity wear-resistant copper alloy comprises the following steps:

[0067] S61, smelting: according to the formula, copper, nickel, tin, zinc are put into a vacuum induction furnace for smelting, argon is introduced for protection, the smelting temperature is 1280℃, and the holding time is 25 minutes;

[0068] S62, refining: according to the formula, rare earth elements and carbon nanotube-copper intermediate alloy are added, argon is introduced for protection, stirring is performed for 9 minutes, slag is removed, and a molten alloy is obtained;

[0069] S63, casting: the molten alloy is poured into a water-cooled copper mold, the cooling rate is 100℃ / s, and an ingot is obtained;

[0070] S64, heat treatment: the ingot is subjected to bell-type heat treatment, the process conditions of the bell-type heat treatment are: the atmosphere is a nitrogen atmosphere, the gas flow of the nitrogen atmosphere is 18m 3 / h; solution treatment at 830℃ for 1.5 hours, and then aging treatment at 430℃ for 5.6 hours, and an ingot A is obtained;

[0071] S65, after surface polishing treatment, the ingot A is subjected to rolling and aging treatment in sequence, the total deformation of the rolling is 15%, the pass of the finished product rolling is 2 passes, and the process parameters of the aging treatment are: the temperature is 160℃, the time is 4 hours, the temperature is 180℃, and the time is 8 hours, and a high-conductivity wear-resistant copper alloy is obtained.

[0072] Comparative Example 1

[0073] The same as Example 3, except that the nickel is 7.5% and the tin is 0%.

[0074] Comparative Example 2

[0075] The same as Example 3, except that the nickel is 0% and the tin is 7.5%.

[0076] Comparative Example 3

[0077] The same as Example 3, except that the rare earth element cerium is 0%.

[0078] Comparative Example 4

[0079] The same as Example 3, except that an equal amount of the mixture prepared in Comparative Example 1 is used instead of the carbon nanotube-copper intermediate alloy.

[0080] Comparative Example 5

[0081] The same as Example 3, except that in S64, heat treatment: the ingot is subjected to bell-type heat treatment, the process conditions of the bell-type heat treatment are: the atmosphere is a nitrogen atmosphere, the gas flow of the nitrogen atmosphere is 18m 3 / h; solution treatment at 830℃ for 1.5 hours, and an ingot A is obtained.

[0082] Comparative Example 6

[0083] The same as Example 3, except that in S64, heat treatment: the ingot was subjected to bell-type heat treatment, and the process conditions of the bell-type heat treatment were as follows: the atmosphere was a nitrogen atmosphere, the gas flow of the nitrogen atmosphere was 18 m 3 / h; and the ingot was aged at 430℃ for 5.6 hours to obtain ingot A.

[0084] Performance test

[0085] The high-conductivity wear-resistant copper alloy prepared in Example 1, Example 3 and Comparative Examples 1-6 was sampled and subjected to the following performance tests.

[0086] The tensile strength was tested according to GB / T 34505-2017 room temperature tensile test method.

[0087] The elongation was tested according to GB / T 22834505-2017 room temperature tensile test method.

[0088] The conductivity was expressed in the unit of international annealed copper standard (%IACS) to represent the conductivity of the copper alloy.

[0089] The hardness was tested according to GB / T 4340.1-2009 metal material Vickers hardness method.

[0090] The wear resistance was tested according to ASTM G65 standard (dry friction condition, load 50N, rotation speed 200rpm).

[0091] Table 1 Performance test

[0092]

[0093] According to the analysis of the data in Table 1, it can be seen that:

[0094] 1) The high-conductivity wear-resistant copper alloy prepared in Example 1-Example 3 has excellent conductivity, wear resistance, and high strength and toughness balance, and is suitable for application in power transmission busbar, high-speed train contact line or marine engineering corrosion-resistant connector.

[0095] 2) According to the comparative analysis of the performance of the high-conductivity wear-resistant copper alloy prepared in Example 3 and Comparative Examples 1-2, it is shown that the mass ratio of nickel to tin is 1.5:1, and the two form nanoscale intermetallic compounds (Ni3Sn) to improve the wear resistance and creep resistance of the alloy. At the same time, due to its nanoscale size, it can also effectively reduce the negative impact on the conductivity, ensuring that the alloy has high conductivity. This ratio enhances the mechanical properties of the alloy by forming nanoscale hard phases, while maintaining its excellent conductivity.

[0096] 3) The comparative analysis of the properties of the high-conductivity wear-resistant copper alloy obtained in combination with Example 3 and Comparative Example 3 shows that the rare earth element Ce reacts with impurities such as oxygen and sulfur to form high-melting-point compounds (such as Ce2O3), reduces the segregation of grain boundary impurities, reduces electron scattering, and improves electrical conductivity. The rare earth element Ce inhibits grain growth, hinders grain boundary migration by adsorbing at the grain boundary, refines the grain size, and improves the strength and toughness of the alloy. The rare earth element Ce can also combine with the dispersion strengthening phase Ni3Sn to further optimize the grain boundary structure, reduce defects, and improve the overall performance.

[0097] 4) The comparative analysis of the properties of the high-conductivity wear-resistant copper alloy obtained in combination with Example 3 and Comparative Example 4 shows that the carbon nanotube-copper intermediate alloy prepared in the present application uses the hydroxyl functional groups on the surface of the hydroxylated carbon nanotubes to modify the carbon nanotubes with hydroxyphenethylamine, and realizes the dispersion of copper elements and copper powder through the nitrogen-containing groups and hydroxyl groups, thereby preparing a carbon nanotube-copper intermediate alloy with smaller particle size; thereby further improving the dispersibility 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.

[0098] 5) The comparative analysis of the properties of the high-conductivity wear-resistant copper alloy obtained in combination with Example 3 and Comparative Example 5-Comparative Example 6 shows that in step S64, solid solution treatment and aging treatment are used to utilize their combined effects. High-temperature solid solution makes nickel, tin and other elements fully dissolve in the copper matrix, eliminating the composition segregation and internal stress caused by rapid cooling (S63). The dissolved coarse Ni3Sn phase provides a uniform supersaturated solid solution for subsequent nano-scale precipitation. The combination of rapid cooling and solid solution treatment improves the uniformity of the matrix. The medium-temperature aging promotes the uniform precipitation of Ni3Sn phase at the nanometer scale (rather than grain boundary segregation), reducing the negative impact of lattice distortion on electrical conductivity. The precipitated phase acts as a second phase strengthening particle, improving the hardness and wear resistance of the alloy. The subsequent rolling (S65) forms a superimposed effect of "precipitation strengthening + work hardening": the aging precipitated phase hinders dislocation movement, and rolling further refines the grain size, synergistically improving the strength and toughness balance.

[0099] The above examples are only used to explain the technical solutions of the present application and are not limited thereto. Although the above examples have been specifically described, those skilled in the art should understand that the specific embodiments of the present application can still be modified or replaced by equivalents without departing from the spirit and scope of the present application. Any modification and equivalent replacement within the spirit and scope of the present application should be covered within the protection scope of the present application.

Claims

1. A high-conductivity wear-resistant copper alloy characterized by, The high-conductivity wear-resistant copper alloy comprises the following raw materials in percentage by mass: nickel: 3-6%, tin: 2-5%, zinc: 1-3%, rare earth elements: 0.1-0.5%, carbon nanotube-copper intermediate alloy: 0.8-1.2%, and the balance being copper, wherein the rare earth elements are one of cerium and lanthanum, the conductivity of the high-conductivity wear-resistant copper alloy is greater than or equal to 94% IACS, and the Vickers hardness is greater than or equal to 120 HV. The carbon nanotube-copper intermediate alloy comprises the following raw materials in parts by mass: hydroxylated carbon nanotubes 15-18 parts, ethanol 800 parts, copper ethoxide 20-25 parts, copper powder 20-25 parts, hydroxyphenylethanolamine 2-3 parts, and a tris-hydroxymethyl aminomethane hydrochloride solution with a pH of 7.3 100-110 parts. The preparation method of the carbon nanotube-copper intermediate alloy comprises the following steps: S51, mixing hydroxylated carbon nanotubes, hydroxyphenylethanolamine and ethanol according to parts by mass, ultrasonic treatment for 30-40 minutes to obtain a carbon nanotube dispersion; S52, adding copper ethoxide, copper powder and a tris-hydroxymethyl aminomethane hydrochloride solution to the carbon nanotube dispersion, stirring until uniform, heating to 52°C 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 the carbon nanotube-copper intermediate alloy, wherein the reducing atmosphere is a mixture of argon and hydrogen, and the volume fraction of hydrogen is 12-15%.

2. The high-conductivity wear-resistant copper alloy of claim 1, wherein, The mass ratio of nickel to tin is (1.2-1.5):1, and the two elements synergistically form nanoscale intermetallic compounds (Ni3Sn) to improve the wear resistance and creep resistance of the alloy.

3. The high-conductivity wear-resistant copper alloy of claim 1, wherein, The rare earth elements are cerium, and the addition amount is 0.2-0.3%, which is used for grain refinement.

4. A method of producing the high-conductivity wear-resistant copper alloy as claimed in any one of claims 1 to 3, characterized in that, The method comprises the following steps: S61, melting: placing copper, nickel, tin and zinc into a vacuum induction furnace for melting, and passing in argon protection, the melting temperature is 1250-1300°C, and the holding time is 20-30 minutes; S62, refining: adding rare earth elements and carbon nanotube-copper intermediate alloy, passing in argon protection, stirring for 8-10 minutes, and removing the slag to obtain a molten alloy; S63, casting: pouring the molten alloy into a water-cooled copper mold, and the cooling rate is greater than or equal to 80°C / s to obtain an ingot; S64, heat treatment: performing bell jar heat treatment on the ingot to obtain an ingot A; S65, after surface polishing treatment, the ingot A is sequentially subjected to rolling and aging treatment to obtain the high-conductivity wear-resistant copper alloy.

5. The preparation method of a highly conductive and wear-resistant copper alloy according to claim 4, characterized in that, In step S63, the cooling rate is 90-100°C / s.

6. The preparation method of a highly conductive and wear-resistant copper alloy according to claim 4, wherein In step S64, the process conditions of the bell jar heat treatment are: the atmosphere is a nitrogen atmosphere, the gas flow of the nitrogen atmosphere is 15-20 m 3 / h; solid solution treatment at 800-850 °C for 1-2 hours, followed by aging treatment at 400-450 °C for 5-6 hours.

7. The method for preparing a highly conductive and wear-resistant copper alloy according to claim 4, wherein: In step S65, the total deformation amount of rolling is 10-20%, and the finished product is rolled for 2-3 passes; the process parameters of the aging treatment are as follows: the first step temperature is 160°C, the holding time is 4 hours, the second step temperature is 180°C, and the holding time is 8 hours.

8. Use of the high-conductivity wear-resistant copper alloy according to any one of claims 1 to 3, characterized in that The high-conductivity wear-resistant copper alloy is used for power transmission busbars, high-speed train contact wires or marine engineering corrosion-resistant connectors.

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