Electrical round copper wire
Electrical round copper wire is a round wire made from high-purity copper through drawing, annealing, and other processes. Its excellent electrical conductivity and good mechanical properties make it a core conductive material for electrical equipment such as wires and cables, motors, and appliances. Available in a wide range of diameters, from ultra-fine 0.05 mm to thick 10 mm, the appropriate specification can be selected based on different application scenarios. T1 and T2 copper are commonly used. T2 copper has a copper content of ≥99.90%, low impurity content, and excellent electrical conductivity, making it suitable for most electrical equipment. However, some specialized applications utilize alloy round copper wires such as Cu-Ag and Cu-Cr to meet specific requirements such as high temperatures and high strength.
The production process for electrical round copper wire requires precision steps, including raw material purification, continuous casting and rolling, cold drawing, annealing, and surface treatment. First, electrolytic copper with a purity exceeding 99.95% is smelted in an industrial frequency induction furnace at a controlled temperature of 1150-1200°C. A phosphorus copper deoxidizer is added to remove oxygen from the molten copper, reducing the oxygen content to below 0.003%. An online degassing system simultaneously removes hydrogen and other gaseous impurities to ensure the purity of the molten copper. Subsequently, continuous casting and rolling are used to form copper rods with a diameter of 8-12 mm. This process enables continuous production, improving efficiency while ensuring uniform copper rod structure. Cold drawing is a key step in determining the dimensional accuracy of round copper wire. The copper rod is drawn through multiple drawing dies, with a reduction rate of 15%-25% per pass, gradually reaching the target diameter. A special lubricant is used during the drawing process to cool and lubricate the wire surface and prevent scratches. The wire is guaranteed to have a diameter tolerance of ≤±0.01 mm and a surface roughness of Ra ≤0.8 μm. Wire that requires further improvement in plasticity undergoes annealing. This involves heating to 400-500°C under nitrogen, holding for 2-4 hours, and then slowly cooling. This reduces the wire’s hardness to HV80-100 and increases its elongation to over 30%, meeting the requirements of processes such as bending and winding. Finally, surface treatments such as tinning, silvering, or painting are applied according to the application requirements. Tinned copper wire improves weldability and corrosion resistance, while enameled copper wire is used for insulation in motor windings.
The performance advantages of electrical round copper wire have made it an irreplaceable position in high-end electrical equipment. First, its excellent electrical conductivity. T2 electrical round copper wire has a conductivity of over 97% IACS , far higher than other metal materials such as aluminum and iron. It can effectively reduce energy loss during current transmission, and has obvious advantages in high-voltage cables, precision instruments and other applications that require high electrical conductivity. Second, it has excellent mechanical properties. Properly annealed round copper wire has good plasticity and toughness, can withstand multiple bending and stretching without breaking, and can have a minimum bending radius of 1 times its diameter, making it easy to manufacture windings and connecting components with complex shapes. Third, its outstanding thermal conductivity is excellent. The thermal conductivity of copper is as high as 398W/(m・K). , can quickly dissipate the heat generated by electrical equipment when it is working, reduce the temperature rise of the equipment, and extend its service life, especially in heating equipment such as motors and transformers; fourthly, it has stable corrosion resistance. In a dry environment, a dense oxide film will form on the copper surface, which can effectively resist atmospheric corrosion. It can maintain stable performance for a long time in closed electrical equipment, and its service life can reach decades; fifthly, it has good welding performance. Copper wires can be firmly connected to each other or with other metals through brazing, electric welding, etc. The contact resistance is small and stable, ensuring the reliability of current transmission.
In application scenarios, electrical round copper wire is the “nerves and blood vessels” of electrical equipment, supporting the transmission and conversion of electricity. In the wire and cable industry, high-voltage cables and communication cables mostly use high-purity round copper wire for their conductive cores. For example, 500kV cross-linked polyethylene cables use T2 round copper wire with a diameter of 2-3 mm, which is twisted into multiple strands to achieve high current and low-loss transmission. In the motor manufacturing field, enameled round copper wire is widely used in the stator and rotor windings of various motors. For example, the drive motors of new energy vehicles use high-strength enameled copper wire with a diameter of 0.5-1 mm to ensure high power density and high efficiency. In electrical equipment, the compressor windings of household appliances such as air conditioners and refrigerators, as well as the coils of relays and contactors, all use round copper wire, leveraging its high conductivity and good formability to ensure the normal operation of the equipment. In the electronic information field, ultra-fine round copper wire (diameter ≤ 0.1 mm) is used for integrated circuit leads, micro motor windings, etc., to meet the needs of miniaturization and high precision of electronic equipment. In power systems, core components such as transformer coils and mutual inductor windings also rely on the high conductivity of electrical round copper wire to ensure the efficiency and stability of power conversion.
Industry trends indicate that electrical round copper wire is moving toward ultra-high purity, ultra-fine diameter, and multifunctional properties. Breakthroughs have been achieved in the research and development of ultra-high-purity round copper wire (copper content exceeding 99.999%). Through vacuum melting and regional purification techniques, impurity levels have been reduced to below 10 ppm, while conductivity has been increased to over 99% IACS, meeting the demands of fields such as quantum communications and high-end chips. Continued advancements in the production of ultra-fine round copper wire have enabled the stable production of wire with diameters under 0.01 mm, suitable for high-end devices such as microsensors and precision medical devices. Multifunctional copper wire is increasingly being used, such as nickel-plated round copper wire for improved corrosion resistance, silver-plated round copper wire for enhanced high-frequency conductivity, and graphene-coated round copper wire for enhanced heat dissipation, expanding the application range of round copper wire. Furthermore, the promotion of green production processes, using clean energy for smelting and environmentally friendly lubricants, has increased copper recovery rates to over 95%, reducing energy consumption and pollution during the production process. In the future, with the rapid development of industries such as 5G communications, new energy vehicles, and artificial intelligence, the demand for high-performance electrical round copper wire will continue to grow, driving the industry to achieve greater breakthroughs in material research and development, process optimization, and performance improvement.
