Highly conductive copper alloy wire and process for making same

Abstract

The application relates to the technical field of copper alloy, in particular to a high-conductivity copper alloy wire and a preparation process thereof. The preparation process of the high-conductivity copper alloy wire comprises the following steps: uniformly mixing nano Y2O3 particles and nano CeO2 particles, mixing the particles into CuCrZr alloy powder, then adding composite plated carbon fibers for ball milling, and then performing pressing, sintering, heat treatment, extrusion forming and aging treatment on the obtained alloy composite powder to obtain the high-conductivity copper alloy wire. The nano Y2O3 particles and the nano CeO2 particles serve as reinforcing phase particles, can form multi-scale strengthening sites in the copper alloy matrix, realize fine-grain strengthening, increase the resistance of dislocation movement, effectively improve the tensile strength of the high-conductivity copper alloy wire under the condition of maintaining good conductivity, the addition of the composite plated carbon fibers is beneficial to improving the bonding strength between the carbon fibers and the copper alloy matrix, improving the conductivity of the high-conductivity copper alloy wire, and balancing the conductivity and strength of the high-conductivity copper alloy wire.

Description

Technical Field

[0001] This invention relates to the field of copper alloy technology, and more specifically, to a high-conductivity copper alloy wire and its preparation process. Background Technology

[0002] Copper alloy wires, due to their high mechanical strength, good electrical and thermal conductivity, and ease of pressure processing, are widely used in fields such as railway circuits and electric locomotives, and have become the most widely used conductive material. With the development of high-tech fields, higher performance requirements are being placed on copper alloys, demanding both high strength and high conductivity. However, the current challenge in designing high-strength, high-conductivity copper alloys lies in the fact that any method of increasing the strength of a copper alloy will, to varying degrees, lead to a decrease in its electrical conductivity. For example, when adding reinforcing phases to improve the alloy's strength, these phases may increase grain boundaries, forming more scattering centers, exacerbating electron scattering, reducing electron mobility, and thus decreasing conductivity.

[0003] In addition, carbon fiber itself has good electrical and thermal conductivity, and its density is much lower than that of copper alloy. Adding carbon fiber to copper alloy to prepare wires can optimize mechanical properties and lightweight characteristics while maintaining or improving electrical and thermal conductivity. However, the smooth surface and high chemical inertness of carbon fiber make it difficult to form chemical bonds or mechanical interlocking with the copper alloy matrix, resulting in weak interfacial bonding and easy debonding. This leads to the formation of physical gaps between carbon fiber and copper alloy matrix, increasing the interfacial contact resistance between carbon fiber and copper alloy matrix, causing defects inside the copper alloy wire, reducing the overall conductivity of the copper alloy wire, and also affecting the mechanical properties. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a high-conductivity copper alloy wire and its manufacturing process.

[0005] A process for preparing a high-conductivity copper alloy wire includes the following steps:

[0006] After uniformly mixing nano-Y2O3 particles and nano-CeO2 particles, the resulting mixed powder is added to anhydrous ethanol. Under argon protection, CuCrZr alloy powder is added. After stirring, vacuum drying, grinding and sieving, a pre-composite powder is obtained.

[0007] The pre-composite powder and the composite coated carbon fiber were placed in a ball mill jar and ball-milled, wherein the amount of composite coated carbon fiber added was 0.8 to 2.4% of the weight of the pre-composite powder, to obtain alloy composite powder.

[0008] After the alloy composite powder is pressed, sintered, heat-treated, extruded and aged, a high-conductivity copper alloy wire is obtained.

[0009] Composite coated carbon fiber is carbon fiber with nickel and copper layers sequentially coated on its surface.

[0010] Furthermore, the preparation of CuCrZr alloy powder includes the following steps:

[0011] Copper powder, chromium powder, and zirconium powder are placed in a ball mill jar. Under argon protection, stainless steel grinding balls are added at a ball-to-material weight ratio of (10-15):1. The mixture is then ball-milled using a high-energy ball mill at a speed of 200-400 rpm for 24-40 hours to obtain CuCrZr alloy powder.

[0012] Furthermore, the composition of the CuCrZr alloy powder is as follows:

[0013] Chromium powder 0.6-0.8 wt%, zirconium powder 0.1-0.3 wt%, and the balance is copper powder. All copper powder, chromium powder and zirconium powder are spherical particles.

[0014] Furthermore, the specific preparation steps of the pre-composite powder include:

[0015] Nano-Y2O3 particles and nano-CeO2 particles were mixed at a weight ratio of 1:(0.5~1.5) and stirred until homogeneous to obtain a mixed powder.

[0016] Add 0.5–3 parts by weight of the mixed powder to 200–300 parts by weight of anhydrous ethanol and ultrasonically disperse for 10–30 min to obtain a mixed powder suspension. Under argon protection, slowly add 100–150 parts by weight of CuCrZr alloy powder to the mixed powder suspension and stir continuously for 1–3 h to fully impregnate the CuCrZr alloy powder in the mixed powder suspension to obtain a mixed slurry.

[0017] The mixed slurry was placed in a vacuum drying oven and dried at 70–90°C for 2–4 hours. Subsequently, it was ground and sieved to obtain a pre-composite powder.

[0018] Furthermore, the specific preparation steps of the alloy composite powder include:

[0019] The pre-composite powder and composite coated carbon fiber are placed in a ball mill jar. The amount of composite coated carbon fiber added is 0.8-2.4% of the weight of the pre-composite powder. Under argon protection, stainless steel grinding balls are added at a ball-to-powder weight ratio of (10-15):1. The mixture is then ball-milled using a high-energy ball mill at a speed of 200-400 rpm for 6-12 hours to obtain the alloy composite powder.

[0020] Furthermore, the specific preparation steps for composite coated carbon fibers include:

[0021] After roughening, sensitization and activation treatment, carbon fiber is obtained as pretreated carbon fiber. The pretreated carbon fiber is added to the plating solution and fully immersed. Then, it is placed in a water bath at 75-90°C and stirred continuously for 30-60 minutes. After filtration and drying, nickel-plated carbon fiber is obtained.

[0022] A DC regulated power supply was used, with nickel-plated carbon fiber as the cathode and high-purity copper plate as the anode. The nickel-plated carbon fiber and high-purity copper plate were placed in the electroplating solution, and the current density was controlled at 0.5-1.5 A / dm2, the temperature at 20-30℃, and the electroplating time at 60-90 min. After electroplating, the carbon fiber was washed with water and dried to obtain the composite coated carbon fiber.

[0023] Furthermore, the plating solution uses deionized water as a solvent and includes the following components: 20-30 g / L nickel sulfate, 25-35 g / L sodium hypophosphite, 10-20 g / L ammonium chloride, and 10-20 g / L sodium citrate, with a pH value of 3-5; the electroplating solution includes the following components: 40-60 g / L copper sulfate, 80-120 g / L potassium citrate, 0.3-0.4 g / L OP-10 emulsifier, and 10-15 g / L potassium nitrate.

[0024] Furthermore, the specific preparation steps for high-conductivity copper alloy wires include:

[0025] The alloy composite powder is placed in a mold and pressed at a pressure of 100-200 MPa to obtain an alloy composite billet. The alloy composite billet is then placed in a sintering furnace for sintering. Under argon protection, the temperature is raised to 920-1000℃ at a heating rate of 5-10℃ / min and the pressure is 100-300 MPa. The temperature is held for 1-2 hours. After the holding period, the temperature is lowered with the furnace to obtain an alloy composite block.

[0026] The alloy composite block is placed in a heat treatment furnace and heated to 800-900℃, then quickly transferred to a hydraulic press for extrusion molding. After extrusion molding, it is held at 450-550℃ for 2-4 hours. After the holding period, it is air-cooled to room temperature to obtain a high-conductivity copper alloy wire.

[0027] Furthermore, the extrusion ratio for extrusion molding is 20 to 40.

[0028] A high-conductivity copper alloy wire is prepared by the aforementioned high-conductivity copper alloy wire preparation process.

[0029] The present invention has the following advantages:

[0030] 1. In this invention, by incorporating reinforcing phase particles—nano-Y2O3 particles and nano-CeO2 particles—into CuCrZr powder, the lattice constants of these two highly thermally stable nanoparticles, nano-Y2O3 particles and nano-CeO2 particles, exhibit a moderate mismatch with the copper alloy matrix. This allows the nano-Y2O3 particles and nano-CeO2 particles to not only act as heterogeneous nucleation sites, forming multi-scale strengthening sites in the copper alloy matrix, which is beneficial for suppressing copper grain growth, achieving fine-grain strengthening, and increasing the resistance to dislocation movement, but also... The synergistic multi-scale distribution of nano-CeO2 particles inhibits the growth of copper grains through both grain boundary blocking and intragranular anchoring, achieving a continuous grain refinement strengthening effect. This strengthening effect is superior to that of using single nano-Y2O3 particles and nano-CeO2 particles, effectively improving the tensile strength of copper alloy wires. Moreover, after the reinforcing phase particles, nano-Y2O3 particles and nano-CeO2 particles, cooperate to achieve a nanoscale dispersed distribution, the impact on electron scattering is small, avoiding the formation of large-size scattering sources through local agglomeration, and the conductivity can still be maintained at the level of 85.8-82.1% IACS.

[0031] 2. In this invention, a layer of nickel is first plated on the surface of the carbon fiber. Utilizing the better compatibility and bonding force between nickel and carbon fiber, a strongly bonded inner plating layer is formed on the carbon fiber surface. This nickel layer acts as an anchoring and transition layer, providing a stable and reliable substrate for the outer copper plating layer. Then, copper ions are reduced and deposited on the surface of the nickel layer to form a copper layer. Since nickel and copper have similar lattice constants, they can form a "metallurgical bond," creating a continuous conductive path between the carbon fiber and the copper alloy matrix. This effectively enhances the interfacial bonding force between the carbon fiber and the copper alloy matrix, promotes electron transport at the interface between the carbon fiber and the copper alloy matrix, avoids interfacial gaps between the carbon fiber and the copper alloy matrix, reduces electron scattering loss at the interface, eliminates contact resistance at heterogeneous interfaces, and thus improves the conductivity of the copper alloy wire. Simultaneously, the high strength characteristics of the carbon fiber can be transferred to the copper matrix through this composite plating layer of nickel and copper, forming a "rigid skeleton-flexible matrix" composite structure. When the alloy is under stress, the carbon fiber bears the main stress, while the copper alloy matrix disperses the stress and inhibits brittle fracture of the carbon fiber, thereby improving the mechanical properties of the copper alloy wire.

[0032] 3. In this invention, the amount of composite coated carbon fiber added is controlled within 0.8% to 2.4% of the weight of the pre-composite powder. Within this range, the composite coated carbon fiber can be uniformly dispersed in the alloy composite powder, promoting the formation of an effective stress transmission network and conductive path in the matrix, effectively balancing the conductivity and strength of the copper alloy wire. When the addition amount is less than 0.8%, the composite coated carbon fiber is sparsely distributed in the copper alloy matrix, failing to form a continuous stress transmission network and conductive path, resulting in insignificant strengthening and conductivity gains. When the addition amount exceeds 2.4%, the composite coated carbon fiber is prone to agglomeration, failing to fully coat the copper matrix, forming "interfacial voids" and "conductive islands," leading to a decrease in conductivity. Simultaneously, the mechanical properties of the copper alloy wire will deteriorate due to stress concentration caused by the agglomerates. Detailed Implementation

[0033] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0034] Example 1

[0035] A manufacturing process for a high-conductivity copper alloy wire specifically includes the following steps:

[0036] S1: Preparation of CuCrZr alloy powder

[0037] Copper powder, chromium powder, and zirconium powder were placed in a ball mill jar. Under argon protection, stainless steel grinding balls were added at a ball-to-material weight ratio of 12:1. The mixture was then ball-milled using a high-energy ball mill at a speed of 300 rpm for 32 hours to obtain CuCrZr alloy powder. The ratio of copper powder, chromium powder, and zirconium powder was: 0.7 wt% chromium powder, 0.2 wt% zirconium powder, with the remainder being copper powder. All three powders were spherical particles.

[0038] S2: Preparation of pre-composite powder

[0039] S2.1: Mix nano-Y2O3 particles with a particle size range of 30-50nm and nano-CeO2 particles with a particle size range of 10-20nm at a weight ratio of 1:1. After mixing evenly, a mixed powder is obtained.

[0040] S2.2: 1.75 parts by weight of mixed powder were added to 250 parts by weight of anhydrous ethanol and ultrasonically dispersed for 20 min to obtain a mixed powder suspension. Under argon protection, 125 parts by weight of CuCrZr alloy powder were slowly added to the mixed powder suspension and stirred continuously for 2 h to fully impregnate the CuCrZr alloy powder in the mixed powder suspension to obtain a mixed slurry.

[0041] S2.3: Place the mixed slurry in a vacuum drying oven and dry it at 80°C for 3 hours. Then, grind and sieve it to obtain a pre-composite powder.

[0042] S3: Preparation of composite coated carbon fiber

[0043] S3.1: Carbon fiber is added to a roughening solution for oxidative roughening. The solid-liquid mass ratio of carbon fiber to roughening solution is 1:20. The roughening solution is a mixed acid solution of concentrated nitric acid and concentrated sulfuric acid in a volume ratio of 3:1. The mixture is stirred in an oil bath at 80°C for 2 hours. After filtration, washing with water until pH=7, and drying, the roughened carbon fiber is obtained.

[0044] S3.2: Add the roughened carbon fiber to the sensitizing solution. The solid-liquid mass ratio of the roughened carbon fiber to the sensitizing solution is 1:20. The composition of the sensitizing solution is 30 g / L stannous chloride, 30 g / L hydrogen chloride and 2 g tin particles. Disperse ultrasonically for 10 min, let stand for 20 min, filter, and obtain the sensitized carbon fiber.

[0045] S3.3: The sensitized carbon fiber is added to the activation solution. The solid-liquid mass ratio of the sensitized carbon fiber to the activation solution is 1:25. The activation solution consists of 0.4 g / L palladium chloride and 20 g / L hydrogen chloride. The mixture is left to stand for 40 min. Then, it is filtered, washed with water and dried to obtain the pretreated carbon fiber.

[0046] S3.4: The pretreated carbon fiber is added to the plating solution, which uses deionized water as a solvent and includes the following components: 25 g / L nickel sulfate, 30 g / L sodium hypophosphite, 15 g / L ammonium chloride, and 15 g / L sodium citrate. The pH of the plating solution is 4. After thorough wetting, the carbon fiber is placed in a water bath at 82°C and stirred continuously for 45 min. After filtration and drying, nickel-plated carbon fiber is obtained.

[0047] S3.5: A DC regulated power supply is used, with nickel-plated carbon fiber as the cathode and high-purity copper plate as the anode. The nickel-plated carbon fiber and high-purity copper plate are placed in the electroplating solution, which consists of 50 g / L copper sulfate, 100 g / L potassium citrate, 0.35 g / L OP-10 emulsifier, and 12.5 g / L potassium nitrate. The current density is controlled at 1 A / dm², the temperature at 25℃, and the electroplating time at 75 min. After electroplating, the carbon fiber is washed with water and dried to obtain the composite coated carbon fiber.

[0048] S4: Preparation of alloy composite powder

[0049] The pre-composite powder and composite coated carbon fiber were placed in a ball mill jar. The amount of composite coated carbon fiber added was 1.6% of the weight of the pre-composite powder. Under argon protection, stainless steel grinding balls were added at a ball-to-material weight ratio of 12:1. The mixture was ball-milled using a high-energy ball mill at a speed of 300 rpm for 9 hours to obtain the alloy composite powder.

[0050] S5: Preparation of high conductivity copper alloy wires

[0051] S5.1: The alloy composite powder is placed in a mold and pressed at a pressure of 150 MPa to obtain a cylindrical alloy composite billet. The alloy composite billet is placed in a sintering furnace for sintering. Under argon protection, the temperature is raised to 960℃ at a heating rate of 7.5℃ / min and the pressure is 200 MPa. The temperature is held for 1.5 hours. After the holding time is completed, the temperature is lowered with the furnace to obtain the alloy composite block.

[0052] S5.2: The alloy composite block is placed in a heat treatment furnace and heated to 850°C. Then it is quickly transferred to a hydraulic press for extrusion molding with an extrusion ratio of 30. After extrusion molding, it is held at 500°C for 3 hours. After the holding period, it is air-cooled to room temperature to obtain a high-conductivity copper alloy wire.

[0053] Example 2

[0054] A manufacturing process for a high-conductivity copper alloy wire specifically includes the following steps:

[0055] S1: Preparation of CuCrZr alloy powder

[0056] Copper powder, chromium powder, and zirconium powder were placed in a ball mill jar. Under argon protection, stainless steel grinding balls were added at a ball-to-material weight ratio of 15:1. The mixture was then ball-milled using a high-energy ball mill at a speed of 400 rpm for 40 hours to obtain CuCrZr alloy powder. The ratio of copper powder, chromium powder, and zirconium powder was: 0.8 wt% chromium powder, 0.3 wt% zirconium powder, and the remainder being copper powder. All three powders were spherical particles.

[0057] S2: Preparation of pre-composite powder

[0058] S2.1: Mix nano-Y2O3 particles with a particle size range of 30-50nm and nano-CeO2 particles with a particle size range of 10-20nm at a weight ratio of 1:1.5. After mixing evenly, a mixed powder is obtained.

[0059] S2.2: Add 3 parts by weight of the mixed powder to 300 parts by weight of anhydrous ethanol and ultrasonically disperse for 30 min to obtain a mixed powder suspension. Under argon protection, slowly add 150 parts by weight of CuCrZr alloy powder to the mixed powder suspension and stir continuously for 3 h to fully impregnate the CuCrZr alloy powder in the mixed powder suspension to obtain a mixed slurry.

[0060] S2.3: Place the mixed slurry in a vacuum drying oven and dry it at 90°C for 4 hours. Then, grind and sieve it to obtain a pre-composite powder.

[0061] S3: Preparation of composite coated carbon fiber

[0062] S3.1: Carbon fiber is added to a roughening solution for oxidative roughening. The solid-liquid mass ratio of carbon fiber to roughening solution is 1:20. The roughening solution is a mixed acid solution of concentrated nitric acid and concentrated sulfuric acid in a volume ratio of 3:1. The mixture is stirred in an oil bath at 80°C for 2 hours. After filtration, washing with water until pH=7, and drying, the roughened carbon fiber is obtained.

[0063] S3.2: Add the roughened carbon fiber to the sensitizing solution. The solid-liquid mass ratio of the roughened carbon fiber to the sensitizing solution is 1:20. The composition of the sensitizing solution is 30 g / L stannous chloride, 30 g / L hydrogen chloride and 2 g tin particles. Disperse ultrasonically for 10 min, let stand for 20 min, filter, and obtain the sensitized carbon fiber.

[0064] S3.3: The sensitized carbon fiber is added to the activation solution. The solid-liquid mass ratio of the sensitized carbon fiber to the activation solution is 1:25. The activation solution consists of 0.4 g / L palladium chloride and 20 g / L hydrogen chloride. The mixture is left to stand for 40 min. Then, it is filtered, washed with water and dried to obtain the pretreated carbon fiber.

[0065] S3.4: The pretreated carbon fiber is added to the plating solution, which uses deionized water as a solvent and includes the following components: 30 g / L nickel sulfate, 35 g / L sodium hypophosphite, 20 g / L ammonium chloride, and 20 g / L sodium citrate. The pH of the plating solution is 5. After thorough wetting, the carbon fiber is placed in a water bath at 90°C and stirred continuously for 60 min. After filtration and drying, nickel-plated carbon fiber is obtained.

[0066] S3.5: A DC regulated power supply is used, with nickel-plated carbon fiber as the cathode and high-purity copper plate as the anode. The nickel-plated carbon fiber and high-purity copper plate are placed in the electroplating solution, which consists of 60 g / L copper sulfate, 120 g / L potassium citrate, 0.4 g / L OP-10 emulsifier, and 15 g / L potassium nitrate. The current density is controlled at 1.5 A / dm², the temperature at 30℃, and the electroplating time at 90 min. After electroplating, the carbon fiber is washed with water and dried to obtain the composite coated carbon fiber.

[0067] S4: Preparation of alloy composite powder

[0068] The pre-composite powder and composite coated carbon fiber were placed in a ball mill jar. The amount of composite coated carbon fiber added was 2.4% of the weight of the pre-composite powder. Under argon protection, stainless steel grinding balls were added at a ball-to-material weight ratio of 15:1. The mixture was ball-milled using a high-energy ball mill at a speed of 400 rpm for 12 hours to obtain the alloy composite powder.

[0069] S5: Preparation of high conductivity copper alloy wires

[0070] S5.1: The alloy composite powder is placed in a mold and pressed at a pressure of 200 MPa to obtain a cylindrical alloy composite billet. The alloy composite billet is placed in a sintering furnace for sintering. Under argon protection, the temperature is increased to 1000℃ at a heating rate of 10℃ / min and the pressure is 300 MPa. The temperature is held for 2 hours. After the holding time is completed, the temperature is lowered with the furnace to obtain the alloy composite block.

[0071] S5.2: The alloy composite block is placed in a heat treatment furnace and heated to 900°C. Then it is quickly transferred to a hydraulic press for extrusion molding with an extrusion ratio of 30. After extrusion molding, it is held at 550°C for 4 hours. After the holding period, it is air-cooled to room temperature to obtain a high-conductivity copper alloy wire.

[0072] Example 3

[0073] A manufacturing process for a high-conductivity copper alloy wire specifically includes the following steps:

[0074] S1: Preparation of CuCrZr alloy powder

[0075] Copper powder, chromium powder, and zirconium powder were placed in a ball mill jar. Under argon protection, stainless steel grinding balls were added at a ball-to-material weight ratio of 10:1. The mixture was then ball-milled using a high-energy ball mill at a speed of 200 rpm for 24 hours to obtain CuCrZr alloy powder. The ratio of copper powder, chromium powder, and zirconium powder was: 0.6 wt% chromium powder, 0.1 wt% zirconium powder, and the remainder being copper powder. All copper powder, chromium powder, and zirconium powder were spherical particles.

[0076] S2: Preparation of pre-composite powder

[0077] S2.1: Mix nano-Y2O3 particles with a particle size range of 30-50nm and nano-CeO2 particles with a particle size range of 10-20nm at a weight ratio of 1:0.5. After mixing evenly, a mixed powder is obtained.

[0078] S2.2: Add 0.5 parts by weight of the mixed powder to 200 parts by weight of anhydrous ethanol, and ultrasonically disperse for 10 min to obtain a mixed powder suspension. Under argon protection, slowly add 100 parts by weight of CuCrZr alloy powder to the mixed powder suspension and stir continuously for 1 h to fully impregnate the CuCrZr alloy powder in the mixed powder suspension to obtain a mixed slurry.

[0079] S2.3: Place the mixed slurry in a vacuum drying oven and dry it at 70°C for 2 hours. Then, grind and sieve it to obtain a pre-composite powder.

[0080] S3: Preparation of composite coated carbon fiber

[0081] S3.1: Carbon fiber is added to a roughening solution for oxidative roughening. The solid-liquid mass ratio of carbon fiber to roughening solution is 1:20. The roughening solution is a mixed acid solution of concentrated nitric acid and concentrated sulfuric acid in a volume ratio of 3:1. The mixture is stirred in an oil bath at 80°C for 2 hours. After filtration, washing with water until pH=7, and drying, the roughened carbon fiber is obtained.

[0082] S3.2: Add the roughened carbon fiber to the sensitizing solution. The solid-liquid mass ratio of the roughened carbon fiber to the sensitizing solution is 1:20. The composition of the sensitizing solution is 30 g / L stannous chloride, 30 g / L hydrogen chloride and 2 g tin particles. Disperse ultrasonically for 10 min, let stand for 20 min, filter, and obtain the sensitized carbon fiber.

[0083] S3.3: The sensitized carbon fiber is added to the activation solution. The solid-liquid mass ratio of the sensitized carbon fiber to the activation solution is 1:25. The activation solution consists of 0.4 g / L palladium chloride and 20 g / L hydrogen chloride. The mixture is left to stand for 40 min. Then, it is filtered, washed with water and dried to obtain the pretreated carbon fiber.

[0084] S3.4: The pretreated carbon fiber is added to the plating solution, which uses deionized water as a solvent and includes the following components: 20 g / L nickel sulfate, 25 g / L sodium hypophosphite, 10 g / L ammonium chloride, and 10 g / L sodium citrate. The pH of the plating solution is 3. After thorough wetting, the carbon fiber is placed in a water bath at 75°C and stirred continuously for 30 minutes. After filtration and drying, nickel-plated carbon fiber is obtained.

[0085] S3.5: A DC regulated power supply is used, with nickel-plated carbon fiber as the cathode and high-purity copper plate as the anode. The nickel-plated carbon fiber and high-purity copper plate are placed in the electroplating solution, which consists of 40 g / L copper sulfate, 80 g / L potassium citrate, 0.3 g / L OP-10 emulsifier, and 10 g / L potassium nitrate. The current density is controlled at 0.5 A / dm², the temperature at 20℃, and the electroplating time at 60 min. After electroplating, the carbon fiber is washed with water and dried to obtain the composite coated carbon fiber.

[0086] S4: Preparation of alloy composite powder

[0087] The pre-composite powder and composite coated carbon fiber were placed in a ball mill jar. The amount of composite coated carbon fiber added was 0.8% of the weight of the pre-composite powder. Under argon protection, stainless steel grinding balls were added at a ball-to-material weight ratio of 10:1. The mixture was ball-milled using a high-energy ball mill at a speed of 200 rpm for 6 hours to obtain the alloy composite powder.

[0088] S5: Preparation of high conductivity copper alloy wires

[0089] S5.1: The alloy composite powder is placed in a mold and pressed at a pressure of 100 MPa to obtain a cylindrical alloy composite billet. The alloy composite billet is placed in a sintering furnace for sintering. Under argon protection, the temperature is raised to 920°C at a heating rate of 5°C / min and the pressure is 100 MPa. The temperature is held for 1 hour. After the holding time is completed, the temperature is lowered with the furnace to obtain the alloy composite block.

[0090] S5.2: The alloy composite block is placed in a heat treatment furnace and heated to 800°C. Then it is quickly transferred to a hydraulic press for extrusion molding with an extrusion ratio of 30. After extrusion molding, it is held at 450°C for 2 hours. After the holding period, it is air-cooled to room temperature to obtain a high-conductivity copper alloy wire.

[0091] Comparative Example 1

[0092] Compared with Example 1, the difference of Comparative Example 1 is that step S2.1 is removed, and the mixed powder in step S2.2 is replaced with equal parts by weight of nano Y2O3 particles with a particle size range of 30-50 nm. The other steps remain unchanged, and a high conductivity copper alloy wire is prepared, which is referred to as Comparative Example 1.

[0093] Comparative Example 2

[0094] Compared with Example 1, Comparative Example 2 differs in that step S2.1 is removed, and the mixed powder in step S2.2 is replaced with equal parts by weight of nano CeO2 particles with a particle size range of 10-20 nm. The remaining steps remain unchanged, and a high-conductivity copper alloy wire is prepared, which is referred to as Comparative Example 2.

[0095] Comparative Example 3

[0096] Compared with Example 1, the difference of Comparative Example 2 is that step S2 is removed, and the pre-composite powder in step S4 is replaced with an equal weight of CuCrZr alloy powder obtained in step S1. The remaining steps remain unchanged, and a high-conductivity copper alloy wire is prepared. This is referred to as Comparative Example 3.

[0097] Comparative Example 4

[0098] Compared with Example 1, the difference of Comparative Example 4 is that step S3.5 is removed, and the composite coated carbon fiber in step S4 is replaced with an equal weight of nickel-plated carbon fiber obtained in step S3.4. The remaining steps remain unchanged, and a high-conductivity copper alloy wire is prepared. This is referred to as Comparative Example 4.

[0099] Comparative Example 5

[0100] Compared with Example 1, Comparative Example 5 differs in that step S3.4 is removed, the nickel-plated carbon fiber in S3.5 is replaced with an equal weight of the pretreated carbon fiber obtained in step S3.3, copper is directly plated on the surface of the pretreated carbon fiber to obtain copper-plated carbon fiber, the composite-plated carbon fiber in step S4 is replaced with copper-plated carbon fiber, and the remaining steps remain unchanged to prepare a high-conductivity copper alloy wire, which is referred to as Comparative Example 5.

[0101] Comparative Example 6

[0102] Compared with Example 1, Comparative Example 6 differs in that step S3 is removed, and the composite coated carbon fiber in step S4 is replaced with an equal weight of carbon fiber, while the other steps remain unchanged, to prepare a high-conductivity copper alloy wire, which is referred to as Comparative Example 6.

[0103] Comparative Example 7

[0104] Compared with Example 1, the difference of Comparative Example 7 is that in step S4, the amount of composite coated carbon fiber added is 0.6% of the weight of the pre-composite powder, and the other steps remain unchanged. A high conductivity copper alloy wire is prepared and is referred to as Comparative Example 7.

[0105] Comparative Example 8

[0106] Compared with Example 1, the difference of Comparative Example 8 is that in step S4, the amount of composite coated carbon fiber added is 0.7% of the weight of the pre-composite powder, and the other steps remain unchanged. A high conductivity copper alloy wire is prepared and is referred to as Comparative Example 8.

[0107] Comparative Example 9

[0108] Compared with Example 1, the difference of Comparative Example 9 is that in step S4, the amount of composite coated carbon fiber added is 2.5% of the weight of the pre-composite powder, and the other steps remain unchanged. A high conductivity copper alloy wire is prepared and is referred to as Comparative Example 9.

[0109] Comparative Example 10

[0110] Compared with Example 1, Comparative Example 10 differs in that, in step S4, the amount of composite coated carbon fiber added is 2.6% of the weight of the pre-composite powder, while the other steps remain unchanged, and a high-conductivity copper alloy wire is prepared, referred to as Comparative Example 10.

[0111] Tensile strength tests were performed on the high-conductivity copper alloy wires prepared in Examples 1-3 and Comparative Examples 1-10 according to the standard GB / T228-2002; the conductivity performance of the high-conductivity copper alloy wires prepared in Examples 1-3 and Comparative Examples 1-10 was tested using a digital eddy current conductivity meter, and the results are shown in Table 1.

[0112] Table 1:

[0113] Group Tensile strength (MPa) Conductivity (%IACS) Example 1 587.4 85.8 Example 2 584.2 83.6 Example 3 579.9 82.1 Comparative Example 1 552.6 72.4 Comparative Example 2 549.1 75.7 Comparative Example 3 458.5 88.5 Comparative Example 4 557.3 73.3 Comparative Example 5 566.8 76.1 Comparative Example 6 540.5 71.4 Comparative Example 7 554.1 75.5 Comparative Example 8 568.8 78.2 Comparative Example 9 573.6 80.3 Comparative Example 10 562.4 78.9

[0114] As shown in Table 1, the high-conductivity copper alloy wires prepared in Examples 1-3 have better tensile strength and conductivity test results than the high-conductivity copper alloy wires prepared in Comparative Examples 1-10. The tensile strength is ≥579.9MPa and the conductivity is maintained at 85.8-82.1% IACS.

[0115] Based on the test results of Examples 1-3 and Comparative Examples 1-3, it can be seen that Comparative Example 3, without the addition of reinforcing phase particles, only used CuCrZr alloy powder to prepare high-conductivity copper alloy wires, with a conductivity of 88.5% IACS and a tensile strength of only 458.5 MPa. Although the conductivity of the high-conductivity copper alloy wires in Examples 1-3 decreased to some extent, it still remained at the level of 85.8-82.1% IACS. Furthermore, the tensile strength of the high-conductivity copper alloy wires in Examples 1-3 was significantly higher than that in Comparative Example 3. This indicates that although the incorporation of reinforcing phase particles will have a certain impact on conductivity, it can significantly improve the tensile strength of high-conductivity copper alloy wires while ensuring high conductivity, achieving a good balance between high strength and high conductivity. Comparative Example 1 incorporated only nano-Y2O3 particles with a particle size range of 30–50 nm, and Comparative Example 2 incorporated only nano-CeO2 particles with a particle size range of 10–20 nm. In terms of tensile strength, Comparative Example 1 had a tensile strength of 552.6 MPa and a conductivity of 72.4% IACS, while Comparative Example 2 had a tensile strength of 549.1 MPa and a conductivity of 75.7% IACS. Both were lower than the tensile strength and conductivity of Examples 1–3. This indicates that the incorporation of a single nano-Y2O3 particle or nano-CeO2 particle has a limited effect on improving the tensile strength of copper alloy wires and can easily lead to a significant decrease in conductivity. However, the simultaneous incorporation of nano-Y2O3 particles and nano-CeO2 particles can synergistically play the role of reinforcing phase particles, forming multi-scale strengthening sites in the copper alloy matrix. This more effectively inhibits copper grain growth, increases dislocation movement resistance, and reduces the influence of electron scattering, thereby maintaining a high level of conductivity while ensuring high tensile strength.

[0116] Based on the test results of Examples 1-3 and Comparative Examples 4-6, it can be seen that compared with Comparative Examples 4-6 which added copper-plated carbon fiber, nickel-plated carbon fiber, or carbon fiber, the high-conductivity copper alloy wires obtained in Examples 1-3 have better conductivity and tensile strength. This indicates that sequentially plating nickel and copper layers on the surface of carbon fiber can effectively improve the interfacial bonding strength between carbon fiber and copper alloy matrix, promote electron transport at the carbon fiber-copper matrix interface, reduce electron scattering loss at the interface, improve the conductivity of high-conductivity copper alloy wires, and better optimize the mechanical properties of high-conductivity copper alloy wires.

[0117] Based on the test results of Examples 1-3 and Comparative Examples 7-10, it can be seen that when the amount of composite coated carbon fiber added is less than or exceeds 0.8% to 2.4% of the weight of the pre-composite powder, the conductivity and mechanical properties of the high conductivity copper alloy wire will be affected. Specifically, when the amount of composite coated carbon fiber added is less than 0.8% of the weight of the pre-composite powder, the enhancement effect on conductivity and mechanical properties is insufficient. When the amount of composite coated carbon fiber added is greater than 2.4% of the weight of the pre-composite powder, the conductivity and mechanical properties deteriorate.

[0118] It should be understood that those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims. Parts not described in detail in this specification are prior art known to those skilled in the art.

Claims

1. A manufacturing process for a high-conductivity copper alloy wire, characterized in that, Includes the following steps: After uniformly mixing nano-Y2O3 particles and nano-CeO2 particles, the resulting mixed powder is added to anhydrous ethanol. Under argon protection, CuCrZr alloy powder is added. After stirring, vacuum drying, grinding and sieving, a pre-composite powder is obtained. The pre-composite powder and the composite coated carbon fiber were placed in a ball mill jar and ball-milled, wherein the amount of composite coated carbon fiber added was 0.8 to 2.4% of the weight of the pre-composite powder, to obtain alloy composite powder. After the alloy composite powder is pressed, sintered, heat-treated, extruded and aged, a high-conductivity copper alloy wire is obtained. Composite coated carbon fiber is carbon fiber with a nickel layer and a copper layer sequentially coated on its surface; The specific preparation steps of the pre-composite powder include: Nano-Y2O3 particles and nano-CeO2 particles were mixed at a weight ratio of 1:(0.5~1.5) and stirred until homogeneous to obtain a mixed powder. Add 0.5–3 parts by weight of the mixed powder to 200–300 parts by weight of anhydrous ethanol and ultrasonically disperse for 10–30 min to obtain a mixed powder suspension. Under argon protection, slowly add 100–150 parts by weight of CuCrZr alloy powder to the mixed powder suspension and stir continuously for 1–3 h to fully impregnate the CuCrZr alloy powder in the mixed powder suspension to obtain a mixed slurry. The mixed slurry was placed in a vacuum drying oven and dried at 70-90°C for 2-4 hours. Subsequently, it was ground and sieved to obtain a pre-composite powder. The specific preparation steps of alloy composite powder include: The pre-composite powder and composite coated carbon fiber are placed in a ball mill jar. The amount of composite coated carbon fiber added is 0.8-2.4% of the weight of the pre-composite powder. Under argon protection, stainless steel grinding balls are added at a ball-to-material weight ratio of (10-15):

1. The mixture is then ball-milled using a high-energy ball mill at a speed of 200-400 rpm for 6-12 hours to obtain the alloy composite powder. The specific preparation steps for composite coated carbon fibers include: After roughening, sensitization and activation treatment, carbon fiber is obtained as pretreated carbon fiber. The pretreated carbon fiber is added to the plating solution and fully immersed. Then, it is placed in a water bath at 75-90°C and stirred continuously for 30-60 minutes. After filtration and drying, nickel-plated carbon fiber is obtained. A DC regulated power supply was used, with nickel-plated carbon fiber as the cathode and a high-purity copper plate as the anode. The nickel-plated carbon fiber and the high-purity copper plate were immersed in the electroplating solution, and the current density was controlled at 0.5–1.5 A / dm³. 2 The temperature is 20-30℃, the electroplating time is 60-90 minutes, and after electroplating, the carbon fiber is washed and dried to obtain the composite coated carbon fiber.

2. The preparation process of a high-conductivity copper alloy wire according to claim 1, characterized in that, The preparation of CuCrZr alloy powder includes the following steps: Copper powder, chromium powder, and zirconium powder are placed in a ball mill jar. Under argon protection, stainless steel grinding balls are added at a ball-to-material weight ratio of (10-15):

1. The mixture is then ball-milled using a high-energy ball mill at a speed of 200-400 rpm for 24-40 hours to obtain CuCrZr alloy powder.

3. The preparation process of a high-conductivity copper alloy wire according to claim 2, characterized in that, The composition of CuCrZr alloy powder is as follows: Chromium powder 0.6-0.8 wt%, zirconium powder 0.1-0.3 wt%, and the balance is copper powder. All copper powder, chromium powder and zirconium powder are spherical particles.

4. The preparation process of a high-conductivity copper alloy wire according to claim 3, characterized in that, The plating solution uses deionized water as a solvent and includes the following components: 20-30 g / L nickel sulfate, 25-35 g / L sodium hypophosphite, 10-20 g / L ammonium chloride, and 10-20 g / L sodium citrate. The pH value of the plating solution is 3-5. The electroplating solution includes the following components: 40-60 g / L copper sulfate, 80-120 g / L potassium citrate, 0.3-0.4 g / L OP-10 emulsifier, and 10-15 g / L potassium nitrate.

5. The preparation process of a high-conductivity copper alloy wire according to claim 4, characterized in that, The specific preparation steps for high conductivity copper alloy wires include: The alloy composite powder is placed in a mold and pressed at a pressure of 100-200 MPa to obtain an alloy composite billet. The alloy composite billet is then placed in a sintering furnace for sintering. Under argon protection, the temperature is raised to 920-1000℃ at a heating rate of 5-10℃ / min and the pressure is 100-300 MPa. The temperature is held for 1-2 hours. After the holding period, the temperature is lowered with the furnace to obtain an alloy composite block. The alloy composite block is placed in a heat treatment furnace and heated to 800-900℃, then quickly transferred to a hydraulic press for extrusion molding. After extrusion molding, it is held at 450-550℃ for 2-4 hours. After the holding period, it is air-cooled to room temperature to obtain a high-conductivity copper alloy wire.

6. The preparation process of a high-conductivity copper alloy wire according to claim 5, characterized in that, The extrusion ratio for extrusion molding is 20 to 40.

7. A high-conductivity copper alloy wire, characterized in that, It is prepared by the preparation process of a high conductivity copper alloy wire according to any one of claims 1-6.