Preparation process of high-performance copper alloy round wire for electrical use

Abstract

The application relates to a high-performance copper alloy round wire preparation process for electrical use and relates to the technical field of copper alloy round wire preparation, and comprises the following steps: S1, uniformly mixing super-pure copper vacuum melting and a trace amount of rare earth; S2, magnetic field control rapid cooling to make the crystal grains fine and uniform; S3, sectional heating to eliminate stress components and make the components more uniformly distributed; and S4, high-low temperature two-time rolling to refine the crystal grains and keep the strength. The high-performance copper alloy round wire preparation process for electrical use effectively improves the matrix purity and refines the initial crystal grains through vacuum melting of super-high-purity raw materials and rare earth micro-alloying pretreatment, significantly enhances the mechanical strength of the copper alloy round wire while keeping high electrical conductivity, realizes fine and uniform crystal grains and consistent component distribution through magnetic field auxiliary deep undercooling directional solidification and variable temperature gradient homogenization annealing, avoids the segregation and inclusion defects commonly seen in traditional processes, and promotes the uniform precipitation of nanoscale strengthening phases through the synergistic effect of double-temperature-zone dynamic recrystallization rolling and transient chilling in-situ nucleation.

Description

Technical Field

[0001] This invention relates to the field of copper alloy round wire preparation technology, specifically a process for preparing high-performance copper alloy round wire for electrical applications. Background Technology

[0002] Copper alloy round wire is a conductive metal material formed by adding one or more alloying elements (such as rare earth, chromium, magnesium, zinc, etc.) to copper as the base. It has a circular cross-section and is widely used in high-voltage cables, electromagnetic coils, electronic connectors and other fields. Copper alloy round wire needs to have both high conductivity and high strength. It must ensure low resistance loss during current transmission and meet mechanical strength requirements to withstand tensile and bending stresses during installation and operation. It is a key basic material for the power electronics and new energy industries.

[0003] The traditional manufacturing process of copper alloy round wire typically includes the following steps: first, the raw copper is smelted and then alloying elements are added for homogenization; then, a preliminary billet is obtained by casting ingots; next, hot rolling or cold rolling is used for deformation processing; then, drawing is performed to obtain wire of the target diameter; finally, the finished product is manufactured through aging treatment and surface treatment. This process route is relatively mature and stable, and can achieve large-scale industrial production. However, it is relatively crude in terms of performance control, and there is a lack of coordination between the various processes, often resulting in some aspects being neglected while others are addressed, making it difficult to achieve the optimal balance of the overall performance of the product.

[0004] Existing methods for preparing copper alloy round wires have the following shortcomings: First, the purity control of raw materials in the vacuum melting process is not precise enough, affecting the final conductivity. Second, the solidification process lacks external field assistance such as magnetic fields, resulting in coarse and unevenly distributed grains. Third, the annealing and rolling temperatures are controlled in a single way, failing to balance recrystallization refinement with the retention of strengthening phases. Fourth, the cooling rate and aging regime are poorly designed, leading to insufficient nucleation of nano-precipitates and a wide size distribution. Fifth, the mismatch between stress accumulation and release during drawing easily leads to the accumulation of microscopic defects. Sixth, the finishing methods are outdated, resulting in poor surface quality and residual stress control. Therefore, it is urgent to develop an advanced preparation process that can synergistically regulate the microstructure and mechanical and electrical properties to overcome the bottlenecks of existing technologies. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a process for preparing high-performance copper alloy round wire for electrical applications, which combines high purity and high strength, and solves the problem that insufficient control of raw material purity affects the final conductivity.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a process for preparing high-performance copper alloy round wire for electrical applications, comprising the following steps: S1. Ultra-pure copper is vacuum melted and mixed with trace amounts of rare earth elements until homogeneous. S2. Rapid cooling controlled by magnetic field makes the grains finer and more uniform. S3. Segmented heating eliminates stress, resulting in a more uniform distribution of stress components; S4. High and low temperature rolling in two stages refines grains and maintains strength; S5. Rolling followed by rapid cooling and then heat preservation to form nano-reinforced particles; S6. Multiple wire drawing and intermediate annealing processes gradually release internal stress; S7. Two-stage heating and heat preservation enhances strength while maintaining conductivity; S8. Laser correction of bends and comprehensive inspection of qualified packaging.

[0007] Furthermore, in step S1, a high-purity copper matrix with a purity of 99.995%-99.999% is used as the raw material, under a vacuum degree ≤5×10 -4 Ingredient preparation and smelting are carried out under Pa conditions; Trace amounts of rare earth elements Ce and La are introduced, with an addition amount of 0.02%-0.03% of the total weight, and the mass ratio of Ce / La is 1:1.0-1:2.0; Rare earth elements are uniformly distributed in the melt in the form of atomic clusters by electromagnetic stirring, and the initial oxygen content of the melt is controlled to be ≤0.0015wt%, thus inhibiting the formation of coarse oxide inclusions. The electromagnetic stirring frequency is 50Hz, and the magnetic field strength is controlled between 0.05T and 0.1T.

[0008] Furthermore, during the melting process in step S2, an alternating magnetic field is applied with a magnetic field strength of 0.15T-0.25T and a frequency of 100Hz-200Hz to induce Lorentz force in the melt to break dendrites. The cooling rate is (2.5-3.5)×10 4 Rapid solidification by deep supercooling at K / s, using a magnetic field to suppress solute diffusion, refines the primary phase size to 0.8μm-1.8μm; By controlling the average grain diameter within the range of 8μm-12μm, the macroscopic segregation coefficient is reduced to 0.03-0.06; The degree of supercooling ΔT in the deep supercooling process is 150K-200K.

[0009] Furthermore, in step S3, the ingot is placed in an atmosphere-protected furnace and subjected to three-stage variable temperature gradient homogenization annealing. The protective atmosphere is high-purity nitrogen with an oxygen content of less than 5 ppm. The first stage temperature is 830℃-850℃, the holding time is 2.0h-3.0h, and the heating rate is controlled at 5℃ / min-7℃ / min; The second stage temperature is 730℃-750℃, the holding time is 4.0h-5.0h, and the cooling rate is controlled at 3℃ / min-5℃ / min; The third stage temperature is 630℃-650℃, the holding time is 6.0h-8.0h, and the cooling rate is controlled at 3℃ / min-5℃ / min; After treatment, the residual stress inside the ingot is reduced to 15MPa-30MPa, and the component diffusion distance reaches 0.45mm-0.65mm.

[0010] Furthermore, a dual-temperature zone hot-warm composite rolling process is adopted in step S4: The high-temperature zone temperature is set at 630℃-670℃, and the single reduction rate is controlled at 48%-58% to induce complete dynamic recrystallization and refine the grains to 3.5μm-8.5μm; The low-temperature zone temperature is set at 330℃-370℃, the single-pass reduction rate is controlled at 13%-20%, and the dislocation density is maintained at 1.8×10⁻⁶. 14 m -2 -2.8×10 15 m -2 This range forms a subgrain boundary strengthening structure; In particular, the total deformation during the rolling process is controlled within the range of 60%-70% in the early stage.

[0011] Furthermore, in step S5, the water immediately enters an online high-speed water quenching device after rolling. The quenching medium is deionized water with a conductivity of <1μS / cm. The water temperature is controlled at 10℃-20℃ and the water flow rate is 4m / s-6m / s. Achieve transient quenching with a cooling rate ≥120℃ / s; It was then immediately transferred to the preheating chamber and held at 220℃-260℃ for 12-18 minutes to induce the precipitation phase size to be controlled at 3nm-12nm, with a volume fraction of 2.8%-4.2%. A diffusely distributed nano-reinforced phase is formed, with a distribution uniformity fluctuation of less than 5%.

[0012] Furthermore, in step S6: A multi-pass drawing strategy with a total deformation of 92%-96% is adopted, with 15-20 drawing passes. After every 2-3 passes, a low-temperature stress-relief annealing process is performed, with an annealing temperature of 360℃-385℃ and a holding time of 18min-25min. The thickness of the surface oxide layer was controlled between 0.05 μm and 0.08 μm after each annealing. Through the "drawing-annealing" cycle, the cumulative work hardening stress release rate reaches 82%-90%, and the surface roughness Ra value is controlled between 0.08μm and 0.20μm; The lubrication method is a PVA water-based polymer coating.

[0013] Furthermore, in step S7: Implement a non-equilibrium two-stage stepped aging process: The first stage temperature is 410℃-440℃, and the short-term holding time is 25min-45min, which promotes the nucleation of a large number of nano-precipitates. The second stage temperature is 510℃-540℃, and the long holding time is 2.5h-3.5h, which promotes the coarsening growth of the precipitated phase and eliminates residual stress. The final microstructure obtained has a tensile strength of 680MPa-760MPa and an electrical conductivity of 83%-87%IACS. The gradient heating rate is controlled between 1℃ / min and 2℃ / min.

[0014] Furthermore, in step S8: Online laser straightening technology is used, with a laser power density of 0.6 kW / cm². 2 -1.3kW / cm 2 The scanning speed of the light spot is 0.6m / min-1.8m / min, and the straightening accuracy is controlled within ±0.01mm / m-±0.025mm / m; Ultrasonic testing was performed at a frequency of 3MHz-4MHz, and eddy current testing was performed at a frequency of 150kHz-400kHz. Automatically rejects defective products containing micro-cracks, inclusions, or out-of-tolerance dimensions; The surface is cleaned and coated with an antioxidant coating with a thickness of 1.5μm-2.2μm. The drying conditions are 100℃ for 8-12 minutes.

[0015] Furthermore, the copper alloy matrix is ​​a Cu-Cr-Zr series high-strength, high-conductivity copper alloy or iron bronze alloy, wherein the Cr content is 0.06%-0.12%, the Zr content is 0.06%-0.12%, the Fe content is 0.6%-1.2%, and the P content is 0.06%-0.12%. The final round wires produced have a diameter of φ0.5mm-φ5.0mm, a tensile strength of 680MPa-760MPa, a conductivity of 83%IACS-87%IACS, and an elongation of ≥14%. Fatigue life (10) 7 The stress amplitude under the second cycle is 420MPa-470MPa, which is suitable for IGBT modules or new energy vehicle connectors. Product yield ≥ 98.5%, surface roughness Ra value ≤ 0.20μm.

[0016] Compared with the prior art, the technical solution of this application has the following beneficial effects: 1. This high-performance copper alloy round wire manufacturing process for electrical applications effectively improves the purity of the matrix and refines the initial grains through vacuum melting of ultra-high purity raw materials combined with rare earth microalloying pretreatment. This allows the copper alloy round wire to significantly enhance its mechanical strength while maintaining high conductivity. Magnetic field-assisted deep supercooling directional solidification combined with variable temperature gradient homogenization annealing achieves fine and uniform grains with consistent composition distribution, avoiding segregation and inclusion defects common in traditional processes. The synergistic effect of dual-temperature zone dynamic recrystallization rolling and transient quenching in-situ nucleation promotes the uniform precipitation of nanoscale strengthening phases, significantly improving tensile strength and hardness without sacrificing conductivity, thus meeting the dual requirements of high strength and high conductivity for high-end applications.

[0017] 2. The manufacturing process for this high-performance copper alloy round wire for electrical applications incorporates strain gradient accumulation drawing cycles and stress redistribution control technology. This effectively alleviates the accumulation of residual stress during processing, reducing the risk of wire deformation and cracking. Non-equilibrium dual-stage aging control optimizes the segregation behavior of grain boundary elements, achieving an optimal balance between strength and conductivity. Laser stress release straightening combined with multi-dimensional non-destructive screening ensures the straightness qualification rate and internal defect-free detection accuracy of the finished wire. The entire process is closely integrated and synergistic, achieving controllability and repeatability of the production process. The consistency between product batches is good, and the scrap rate is significantly reduced, which is conducive to large-scale industrial production and cost optimization. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the preparation process of the present invention. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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 skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Please see Figure 1 The manufacturing process of a high-performance copper alloy round wire for electrical applications in this embodiment includes the following steps: S1. Ultra-pure copper is vacuum melted and mixed with trace amounts of rare earth elements until homogeneous. S2. Rapid cooling controlled by magnetic field makes the grains finer and more uniform. S3. Segmented heating eliminates stress, resulting in a more uniform distribution of stress components; S4. High and low temperature rolling in two stages refines grains and maintains strength; S5. Rolling followed by rapid cooling and then heat preservation to form nano-reinforced particles; S6. Multiple wire drawing and intermediate annealing processes gradually release internal stress; S7. Two-stage heating and heat preservation enhances strength while maintaining conductivity; S8. Laser correction of bends and comprehensive inspection of qualified packaging.

[0021] A complete process framework for the preparation of high-performance copper alloy round wire for electrical applications was established. Through the systematic connection of eight key steps, full-process control from smelting to finished product was achieved. The close connection and mutual coordination between each process formed an integrated control system of "composition-structure-performance", which not only ensured the integrity of the process, but also ensured the optimal matching between each link. This laid a solid foundation for the subsequent optimization of various detailed parameters, enabling the final product to meet the dual requirements of high strength and high conductivity.

[0022] In step S1, a high-purity copper matrix with a purity of 99.995%-99.999% is used as the raw material, and the process is carried out under a vacuum degree ≤5×10⁻⁶. -4 Ingredient preparation and smelting are carried out under Pa conditions; Trace amounts of rare earth elements Ce and La are introduced, with an addition amount of 0.02%-0.03% of the total weight, and the mass ratio of Ce / La is 1:1.0-1:2.0; Rare earth elements are uniformly distributed in the melt in the form of atomic clusters by electromagnetic stirring, and the initial oxygen content of the melt is controlled to be ≤0.0015wt%, thus inhibiting the formation of coarse oxide inclusions. The electromagnetic stirring frequency is 50Hz, and the magnetic field strength is controlled between 0.05T and 0.1T.

[0023] By using an ultra-high purity copper matrix with trace amounts of rare earth elements, the initial purity of the material is effectively improved and the formation of coarse oxide inclusions is suppressed. Electromagnetic stirring makes the rare earth elements uniformly distributed in the form of atomic clusters, which significantly improves the purity and uniformity of the melt. This provides a high-quality raw material basis for subsequent grain refinement and strengthening phase precipitation, fundamentally ensuring the electrical conductivity and mechanical properties of the product.

[0024] In step S2, an alternating magnetic field is applied during the melting process. The magnetic field strength is 0.15T-0.25T and the frequency is 100Hz-200Hz, which induces the melt to generate Lorentz force to break dendrites. The cooling rate is (2.5-3.5)×10 4 Rapid solidification by deep supercooling at K / s, using a magnetic field to suppress solute diffusion, refines the primary phase size to 0.8μm-1.8μm; By controlling the average grain diameter within the range of 8μm-12μm, the macroscopic segregation coefficient is reduced to 0.03-0.06; The degree of subcooling ΔT during deep subcooling is 150K-200K.

[0025] By applying an alternating magnetic field to induce the Lorentz force in the melt to break the dendrites, and combining this with deep supercooling rapid solidification technology, the size of the primary phase was successfully refined to the submicron level, and the average grain diameter was controlled within 8μm-12μm. At the same time, the macroscopic segregation coefficient was significantly reduced, effectively solving the problems of coarse grains and uneven distribution in traditional solidification processes, and creating conditions for obtaining fine and uniform microstructures in products.

[0026] In step S3, the ingot is placed in an atmosphere protection furnace and three-stage variable temperature gradient homogenization annealing is performed. The protective atmosphere is high-purity nitrogen with an oxygen content of less than 5 ppm. The first stage temperature is 830℃-850℃, the holding time is 2.0h-3.0h, and the heating rate is controlled at 5℃ / min-7℃ / min; The second stage temperature is 730℃-750℃, the holding time is 4.0h-5.0h, and the cooling rate is controlled at 3℃ / min-5℃ / min; The third stage temperature is 630℃-650℃, the holding time is 6.0h-8.0h, and the cooling rate is controlled at 3℃ / min-5℃ / min; After treatment, the residual stress inside the ingot is reduced to 15MPa-30MPa, and the component diffusion distance reaches 0.45mm-0.65mm.

[0027] The three-stage variable temperature gradient homogenization annealing process effectively eliminates residual stress inside the ingot and increases the component diffusion distance to the millimeter level through precise step-by-step temperature control and atmosphere protection. It avoids the limitations of single-stage annealing, achieves the best synergy between stress release and component homogenization, and provides a stable billet state for subsequent rolling processing.

[0028] In step S4, a dual-temperature zone hot-warm composite rolling process is adopted: The high-temperature zone temperature is set at 630℃-670℃, and the single reduction rate is controlled at 48%-58% to induce complete dynamic recrystallization and refine the grains to 3.5μm-8.5μm; The low-temperature zone temperature is set at 330℃-370℃, the single-pass reduction rate is controlled at 13%-20%, and the dislocation density is maintained at 1.8×10⁻⁶. 14 m -2 -2.8×10 15 m -2 This range forms a subgrain boundary strengthening structure; In particular, the total deformation during the rolling process is controlled within the range of 60%-70% in the early stage.

[0029] The dual-temperature zone hot-warm composite rolling process cleverly combines the advantages of high-temperature fully dynamic recrystallization and low-temperature dislocation density retention. It not only achieves significant grain refinement but also forms a subgrain boundary strengthening structure. The reasonable distribution of large deformation in the front section and small deformation in the back section achieves an optimal balance between strength enhancement and plasticity maintenance, effectively preserving the material's toughness and strength while refining the grains.

[0030] In step S5, the rolls immediately enter an online high-speed water quenching device. The quenching medium is deionized water with a conductivity of <1μS / cm. The water temperature is controlled at 10℃-20℃ and the water flow rate is 4m / s-6m / s. Achieve transient quenching with a cooling rate ≥120℃ / s; It was then immediately transferred to the preheating chamber and held at 220℃-260℃ for 12-18 minutes to induce the precipitation phase size to be controlled at 3nm-12nm, with a volume fraction of 2.8%-4.2%. A diffusely distributed nano-reinforced phase is formed, with a distribution uniformity fluctuation of less than 5%.

[0031] The process design of online high-speed water quenching combined with preheating chamber insulation after rolling enables in-situ nucleation of nano-reinforcing phases induced by transient quenching. The resulting diffusely distributed nanoparticles have controllable size and moderate volume fraction, with a distribution uniformity fluctuation of less than 5%. This significantly improves the tensile strength and hardness of the material without sacrificing conductivity, and solves the problem of insufficient precipitation or excessive aggregation of reinforcing phases.

[0032] In step S6: A multi-pass drawing strategy with a total deformation of 92%-96% is adopted, with 15-20 drawing passes. After every 2-3 passes, a low-temperature stress-relief annealing process is performed, with an annealing temperature of 360℃-385℃ and a holding time of 18min-25min. The thickness of the surface oxide layer was controlled between 0.05 μm and 0.08 μm after each annealing. Through the "drawing-annealing" cycle, the cumulative work hardening stress release rate reaches 82%-90%, and the surface roughness Ra value is controlled between 0.08μm and 0.20μm; The lubrication method is a PVA water-based polymer coating.

[0033] The "drawing-annealing" cycle strategy, which combines multiple drawing passes with intermittent low-temperature stress-relief annealing, enables the cumulative work hardening stress release rate to reach 82%-90%, effectively preventing the risk of cracking caused by stress accumulation. At the same time, it keeps the surface roughness at a low level, extends the service life of the mold, and ensures the stability of the wire forming process and the high quality of the finished product surface.

[0034] In step S7: Implement a non-equilibrium two-stage stepped aging process: The first stage temperature is 410℃-440℃, and the short-term holding time is 25min-45min, which promotes the nucleation of a large number of nano-precipitates. The second stage temperature is 510℃-540℃, and the long holding time is 2.5h-3.5h, which promotes the coarsening growth of the precipitated phase and eliminates residual stress. The final microstructure obtained has a tensile strength of 680MPa-760MPa and an electrical conductivity of 83%-87%IACS. The gradient heating rate is controlled between 1℃ / min and 2℃ / min.

[0035] The non-equilibrium two-step aging process precisely controls the growth behavior of nano-precipitates by combining short-term promotion of a large number of nucleations with long-term promotion of coarsening growth. This enables the tensile strength and conductivity of the final product to be optimized simultaneously in terms of microstructure, balancing the contradictory requirements of high strength and high conductivity, and achieving a peak state of performance matching.

[0036] In step S8: Online laser straightening technology is used, with a laser power density of 0.6 kW / cm². 2 -1.3kW / cm 2 The scanning speed of the light spot is 0.6m / min-1.8m / min, and the straightening accuracy is controlled within ±0.01mm / m-±0.025mm / m; Ultrasonic testing was performed at a frequency of 3MHz-4MHz, and eddy current testing was performed at a frequency of 150kHz-400kHz. Automatically rejects defective products containing micro-cracks, inclusions, or out-of-tolerance dimensions; The surface is cleaned and coated with an antioxidant coating with a thickness of 1.5μm-2.2μm. The drying conditions are 100℃ for 8-12 minutes.

[0037] Online laser straightening technology, combined with multi-dimensional non-destructive testing (ultrasonic + eddy current), controls the straightening accuracy within ±0.01mm / m, enabling efficient detection and removal of surface defects and internal cracks. Furthermore, the anti-oxidation coating treatment extends the product's service life, ensuring the flatness pass rate and quality stability of the finished product, and meeting the stringent quality requirements of high-end applications.

[0038] The copper alloy matrix is ​​a Cu-Cr-Zr series high-strength, high-conductivity copper alloy or iron bronze alloy, wherein the Cr content is 0.06%-0.12%, the Zr content is 0.06%-0.12%, the Fe content is 0.6%-1.2%, and the P content is 0.06%-0.12%. The final round wires produced have a diameter of φ0.5mm-φ5.0mm, a tensile strength of 680MPa-760MPa, a conductivity of 83%IACS-87%IACS, and an elongation of ≥14%. Fatigue life (10) 7 The stress amplitude under the second cycle is 420MPa-470MPa, which is suitable for IGBT modules or new energy vehicle connectors. Product yield ≥ 98.5%, surface roughness Ra value ≤ 0.20μm.

[0039] The composition system of Cu-Cr-Zr alloys or iron bronze alloys and the comprehensive performance indicators of the final products are clearly defined, including key parameters such as tensile strength, conductivity, elongation, and fatigue life. Applicable scenarios and product yield targets are also given, providing clear quality standards and quality control basis for industrial production, and ensuring the reliability of products in high-end fields such as IGBT modules and new energy vehicle connectors.

[0040] The working principle of the above embodiment is as follows: First, the purity of the matrix is ​​improved and trace refining elements are introduced through vacuum melting of ultra-high purity raw materials and rare earth micro-alloying pretreatment. Then, magnetic field-assisted deep undercooling directional solidification is used to control the grain nucleation and growth direction, combined with variable temperature gradient homogenization annealing to eliminate segregation defects. Next, grain refinement and dislocation control are achieved through dual-temperature zone dynamic recrystallization rolling, combined with transient quenching to promote in-situ nucleation of nano-precipitates. During the drawing process, strain gradient accumulation drawing and stress redistribution cycles are used to gradually release processing stress and avoid cracking. Finally, non-equilibrium dual-stage aging is used to precisely control grain boundary segregation behavior, combined with laser stress release straightening and multi-dimensional non-destructive screening to obtain the final product. Each process forms a "composition-structure-performance" synergistic control system, achieving simultaneous optimization of strength and conductivity.

[0041] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0042] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A process for manufacturing high-performance copper alloy round wire for electrical applications, characterized in that, Includes the following steps: S1. Ultra-pure copper is vacuum melted and mixed with trace amounts of rare earth elements until homogeneous. S2. Rapid cooling controlled by magnetic field makes the grains finer and more uniform. S3. Segmented heating eliminates stress, resulting in a more uniform distribution of stress components; S4. High and low temperature rolling in two stages refines grains and maintains strength; S5. Rolling followed by rapid cooling and then heat preservation to form nano-reinforced particles; S6. Multiple wire drawing and intermediate annealing processes gradually release internal stress. S7. Two-stage heating and heat preservation enhances strength while maintaining conductivity; S8. Laser correction of bends and comprehensive inspection of qualified packaging.

2. The manufacturing process for a high-performance copper alloy round wire for electrical applications according to claim 1, characterized in that: In step S1, a high-purity copper matrix with a purity of 99.995%-99.999% is used as the raw material, and the process is carried out under a vacuum degree ≤5×10⁻⁶. -4 Ingredient preparation and smelting are carried out under Pa conditions; Trace amounts of rare earth elements Ce and La are introduced, with an addition amount of 0.02%-0.03% of the total weight, and the mass ratio of Ce / La is 1:1.0-1:2.0; Rare earth elements are uniformly distributed in the melt in the form of atomic clusters by electromagnetic stirring, and the initial oxygen content of the melt is controlled to be ≤0.0015wt%, thus inhibiting the formation of coarse oxide inclusions. The electromagnetic stirring frequency is 50Hz, and the magnetic field strength is controlled between 0.05T and 0.1T.

3. The manufacturing process for a high-performance copper alloy round wire for electrical applications according to claim 1, characterized in that: An alternating magnetic field is applied during the melting process in step S2. The magnetic field strength is 0.15T-0.25T and the frequency is 100Hz-200Hz to induce Lorentz force in the melt to break dendrites. The cooling rate is (2.5-3.5)×10 4 Rapid solidification by deep supercooling at K / s, using a magnetic field to suppress solute diffusion, refines the primary phase size to 0.8μm-1.8μm; By controlling the average grain diameter within the range of 8μm-12μm, the macrosegregation coefficient is reduced to 0.03-0.06; The degree of supercooling ΔT in the deep supercooling process is 150K-200K.

4. The manufacturing process for a high-performance copper alloy round wire for electrical applications according to claim 1, characterized in that: In step S3, the ingot is placed in an atmosphere-protected furnace and subjected to three-stage variable temperature gradient homogenization annealing. The protective atmosphere is high-purity nitrogen with an oxygen content of less than 5 ppm. The first stage temperature is 830℃-850℃, the holding time is 2.0h-3.0h, and the heating rate is controlled at 5℃ / min-7℃ / min; The second stage temperature is 730℃-750℃, the holding time is 4.0h-5.0h, and the cooling rate is controlled at 3℃ / min-5℃ / min; The third stage temperature is 630℃-650℃, the holding time is 6.0h-8.0h, and the cooling rate is controlled at 3℃ / min-5℃ / min; After treatment, the residual stress inside the ingot is reduced to 15MPa-30MPa, and the component diffusion distance reaches 0.45mm-0.65mm.

5. The manufacturing process for a high-performance copper alloy round wire for electrical applications according to claim 1, characterized in that: The dual-temperature zone hot-warm composite rolling process is adopted in step S4: The high-temperature zone temperature is set at 630℃-670℃, and the single reduction rate is controlled at 48%-58% to induce complete dynamic recrystallization and refine the grains to 3.5μm-8.5μm; The low-temperature zone temperature is set at 330℃-370℃, the single-pass reduction rate is controlled at 13%-20%, and the dislocation density is maintained at 1.8×10⁻⁶. 14 m -2 -2.8×10 15 m -2 This range forms a subgrain boundary strengthening structure; In particular, the total deformation during the rolling process is controlled within the range of 60%-70% in the early stage.

6. The manufacturing process for a high-performance copper alloy round wire for electrical applications according to claim 1, characterized in that: In step S5, the rolls immediately enter an online high-speed water quenching device. The quenching medium is deionized water with a conductivity of <1μS / cm. The water temperature is controlled at 10℃-20℃ and the water flow rate is 4m / s-6m / s. Achieve transient quenching with a cooling rate ≥120℃ / s; It was then immediately transferred to the preheating chamber and held at 220℃-260℃ for 12-18 minutes to induce the precipitation phase size to be controlled at 3nm-12nm, with a volume fraction of 2.8%-4.2%. A diffusely distributed nano-reinforced phase is formed, with a distribution uniformity fluctuation of less than 5%.

7. The manufacturing process for a high-performance copper alloy round wire for electrical applications according to claim 1, characterized in that: In step S6: A multi-pass drawing strategy with a total deformation of 92%-96% is adopted, with 15-20 drawing passes. After every 2-3 passes, a low-temperature stress-relief annealing process is performed, with an annealing temperature of 360℃-385℃ and a holding time of 18min-25min. The thickness of the surface oxide layer was controlled between 0.05 μm and 0.08 μm after each annealing. Through the "drawing-annealing" cycle, the cumulative work hardening stress release rate reaches 82%-90%, and the surface roughness Ra value is controlled between 0.08μm and 0.20μm; The lubrication method is PVA water-based polymer coating.

8. The process for preparing high-performance copper alloy round wire for electrical applications according to claim 1, characterized in that, In step S7: Implement a non-equilibrium two-stage stepped aging process: The first stage temperature is 410℃-440℃, and the short-term holding time is 25min-45min, which promotes the nucleation of a large number of nano-precipitates. The second stage temperature is 510℃-540℃, and the long holding time is 2.5h-3.5h, which promotes the coarsening growth of the precipitated phase and eliminates residual stress. The final microstructure obtained has a tensile strength of 680MPa-760MPa and an electrical conductivity of 83%-87%IACS. The gradient heating rate is controlled between 1℃ / min and 2℃ / min.

9. The manufacturing process for a high-performance copper alloy round wire for electrical applications according to claim 1, characterized in that: In step S8: Online laser straightening technology is used, with a laser power density of 0.6 kW / cm². 2 -1.3kW / cm 2 The scanning speed of the light spot is 0.6m / min-1.8m / min, and the straightening accuracy is controlled within ±0.01mm / m-±0.025mm / m; Ultrasonic testing was performed at a frequency of 3MHz-4MHz, and eddy current testing was performed at a frequency of 150kHz-400kHz. Automatically rejects defective products containing micro-cracks, inclusions, or out-of-tolerance dimensions; The surface is cleaned and coated with an antioxidant coating with a thickness of 1.5μm-2.2μm. The drying conditions are 100℃ for 8-12 minutes.

10. The manufacturing process for a high-performance copper alloy round wire for electrical applications according to claim 1, characterized in that: The copper alloy matrix is ​​a Cu-Cr-Zr series high-strength, high-conductivity copper alloy or iron bronze alloy, wherein the Cr content is 0.06%-0.12%, the Zr content is 0.06%-0.12%, the Fe content is 0.6%-1.2%, and the P content is 0.06%-0.12%. The final round wires produced have a diameter of φ0.5mm-φ5.0mm, a tensile strength of 680MPa-760MPa, a conductivity of 83%IACS-87%IACS, and an elongation of ≥14%. Fatigue life (10) 7 The stress amplitude under the second cycle is 420MPa-470MPa, which is suitable for IGBT modules or new energy vehicle connectors. Product yield ≥ 98.5%, surface roughness Ra value ≤ 0.20μm.

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