As the core carrier of the power transmission system, the manufacturing process of the jeu de barres en cuivre directly affects the stability of the power grid and equipment life. In this paper, from the material science, processing technology, and quality inspection of three dimensions, the system combines copper busbar manufacturing with 8 key technologies, combined with international standards and industry cutting-edge data (such as GB/T 5585.1-2005 and IEC 60287), revealing high conductivity and high mechanical strength busbar manufacturing logic, and through the performance of comparative tables and process parameter analysis, it provides practical guidance for power equipment manufacturers. Guidance.

Step 1. Material Selection

Copper purity determines electrical conductivity and mechanical strength

Copper busbars need to use electrolytic copper or oxygen-free copper; purity needs to be ≥ 99.95%; silver content control in 0.002%-0.02% can improve creep resistance. Experiments have shown that for every 0.1% reduction in copper purity, the conductivity decreased by about 1.2% IACS (International Annealed Copper Standard), while the loss of tensile strength was up to 5%.

Step 2. Melting process

Charcoal Covering Method for Efficient Deoxidation

When melting in an IF furnace, the surface of the copper liquid needs to be covered with a charcoal layer 135mm thick to reduce the oxygen content to less than ppm and to avoid localized resistance increase caused by copper oxide inclusions. The temperature needs to be precisely controlled at 1145-1155℃ (), and the copper liquid is conveyed through the submerged structure to reduce the bubble residue.

Step 3. Molding process

Continuous extrusion technology to improve the rate of formation

After crystallization in the continuous casting machine, copper rods are continuously extruded at 490°C, with frictional heat replacing external heating, saving energy by 30%. The cross-sectional shrinkage of the extruded copper billet is ≤3%, and the material utilization rate reaches 95%, which is better than 85% in the traditional forging process.

Step 4. Precision Machining

CNC machining ensures ±0.5mm accuracy

When using a three-in-one busbar processing machine (punching + bending + cutting), the error of the punching center distance ≤ 0.5 mm, the bending radius needs to be ≥ 2.5 times the width of the busbar. Surface roughness needs to be ≤ Ra1.6, and enhanced corrosion resistance needs to be enhanced through galvanization (10-20 μm) or chemical polishing.

Step 5. Bending Process

Cold bending process to avoid lattice damage

Copper busbars need to be formed by cold bending; the heating temperature is strictly prohibited from exceeding 250℃ (). Vertical bending and flat bending of the curvature need to be ≤ 2 mm/m and 3mm/m, respectively; after bending, it needs to be annealed, with residual stress reduction of 60% ().

Step 6. Connection Technology

 Torque wrench to guarantee contact reliability

Bolt tightening force needs to comply with the standards of Table 9 , M12 bolt recommended torque of 45-50 N-m). Contact resistance can be reduced to 0.15 μΩ-m² after embossing treatment on the contact surface, which is 40% less than the untreated surface ().

Step 7. Insulation Treatment

Double-layer heat-shrink tubing improves insulation level

Radiation cross-linked polyolefin heat-shrinkable tubing (temperature resistant to 125°C) is used with a thickness of ≥1.2mm and a shrinkage rate of ≥50%. Comparative tests show that the breakdown voltage of double-layer heat-shrinkable tubing reaches 35 kV/mm, which is 80% higher than single-layer.

Step 8. Quality Inspection

Four-dimensional testing system to ensure product consistency

• Electrical properties: conductivity ≥ 100.3% IACS (), insulation resistance ≥ 1000Ω / V ()
• Mechanical properties: hardness ≥ 85HB, bending times ≥ 120 times ()
• Dimensional inspection: three-dimensional laser scanner accuracy ± 0.05mm
• Metallographic analysis: grain size grade ≥6 (ASTM E112)

Conclusion

Barre omnibus en cuivre manufacturing is a fusion of material science and precision machining, which requires the establishment of standardized processes in purity control, molding process, and connection technology. Through the introduction of automated equipment (and real-time monitoring systems), the product qualification rate can be significantly improved. In the future, with the application of copper-silver composites, the current-carrying capacity of copper busbars is expected to exceed 6,000 A/cm², promoting the upgrading of the smart grid.