Current Transfer Performance Of Bimetallic Terminals In Copper-aluminum Transition

In modern power engineering, connecting dissimilar metals always presents challenges. As a specialized component for connecting aluminum cables and copper busbars, the conductivity of the bimetallic lugs component directly affects the stable operation of the entire power distribution system.

How does this hybrid material achieve efficient current carrying capacity?

Copper and aluminum have significantly different conductivity. Copper has a conductivity of approximately 5.8 x 10^7 S/m, while aluminum has approximately 3.5 x 10^7 S/m. bi metal cable lug combines an aluminum tube body with a copper contact surface through a special manufacturing process. This design allows the aluminum cable to be embedded in the aluminum tube cavity, with the copper contact surface fitting against the copper busbar, enabling current to flow between the same metal interfaces. This physical structure reduces resistance fluctuations caused by direct contact between different metals.

The contribution of friction welding process to conductivity consistency

The core of bi metal lugs connectors lies in the treatment of the joint. Currently, the mainstream solution uses friction welding technology, which allows the molecules of the two metals to interpenetrate under high temperature and pressure, forming a dense transition layer.

• Eliminating interface resistance: Because friction welds do not involve solder, they maintain extremely high metal purity. Thermal stability: The mechanical strength of the welded joint often exceeds that of the base material, maintaining consistent deformation under high current impact.

• Uniform current distribution: Molecular-level bonding ensures that charge distribution transcends the limitations of "point contact," achieving full-section current flow.

Addressing the impact of environmental factors on conductivity:

In outdoor or humid environments, metal oxidation is a hidden killer of conductivity. Aluminum readily forms an aluminum oxide film on its surface; this film has insulating properties and rapidly increases contact resistance.

When bi metallic cable lugs leaves the factory, the inner wall of the aluminum tube is usually pre-filled with conductive paste. The active particles in the conductive paste can pierce the residual oxide layer during the crimping process. This method, combined with the fully sealed welding structure of the terminals, prevents air from entering the copper-aluminum joint, maintaining low-loss transmission during long-term operation.