Welding of tubular busbars should be carried out using

Ultrasonic welding, TIG welding, laser welding, and friction stir welding are the primary technologies used for joining tubular busbars, each offering unique advantages in strength, conductivity, and production efficiency.Ultrasonic WeldingUltrasonic welding is a solid-state process that uses high-frequency mechanical vibrations under pressure to join metals without melting them. It is particularly effective for copper-aluminum and copper-copper busbars, producing extremely low contact resistance and high mechanical strength. Connections can withstand tensile forces of 5,000–10,000 N or more, making them suitable for electric vehicles, power electronics, and energy distribution systems. The process is fast, with welding cycles of just a few seconds, and does not require solder or filler materials, reducing costs and material waste while ensuring high precision and reliability .TIG (Tungsten Inert Gas) WeldingTIG welding is ideal for copper tubular busbars, offering precise control and high-quality welds. A tungsten electrode produces the weld while an inert gas, typically argon, shields the area from oxidation. For thicker busbars, a mixture of 75% argon and 25% helium can improve penetration. Preheating and using a V-groove joint can enhance weld quality. TIG welding is versatile for thin to medium-thickness busbars and ensures strong, clean joints suitable for high-current applications .Laser WeldingLaser welding uses a focused high-energy beam to join materials with minimal heat-affected zones, reducing distortion and post-weld treatment. It produces welds stronger than the base material, supports automation, and typically requires no filler material. This method is suitable for complex shapes and high-strength tubular busbars, offering high precision and speed for mass production .Friction Stir Welding (FSW)Friction stir welding is a solid-state technique where a rotating tool generates frictional heat to soften and mechanically forge the materials together. It avoids melting, reducing defects like porosity and cracks. FSW provides high-strength, high-toughness joints and is particularly useful for lightweight, high-current busbars in new energy equipment. It also produces no harmful fumes, making it environmentally friendly .Additional ConsiderationsMaterial Compatibility: Copper, aluminum, and their alloys are commonly used. Ultrasonic and friction stir welding are effective for dissimilar metals.Mechanical and Electrical Performance: Solid-state methods like ultrasonic and friction stir welding provide superior mechanical strength and low electrical resistance.Production Efficiency: Ultrasonic and laser welding offer rapid cycles suitable for high-volume manufacturing, while TIG welding is preferred for precision and smaller-scale applications.Surface Treatment: Coatings or pre-cleaning may be necessary to prevent oxidation and ensure optimal conductivity, especially for aluminum busbars . In summary, the choice of welding technology for tubular busbars depends on material type, thickness, production volume, and required mechanical and electrical performance. Ultrasonic welding is highly efficient for high-volume, dissimilar metal applications, TIG welding excels in precision, laser welding supports automation and complex geometries, and friction stir welding provides robust solid-state joints for demanding applications.