Tensile behaviour of the dissimilar friction stir welding between pure copper and aluminium 1050

Abstract

Copper-aluminum hybrid connectors play a crucial role in electric vehicles, but welding these metals together poses a significant challenge due to their distinct physical and mechanical properties. Friction stir welding, a solid- state welding technique, proves to be suitable for joining dissimilar metals. In this study, friction stir welding was employed to create a joint between pure copper 1100 and aluminum 1050 plates, each with a thickness of 5 mm. The fabricated results showed that a significant amount of copper was dispersed into the aluminum side to establish the bonding. The bonding strength was evaluated through tensile testing, while the macrostructure and fracture paths of the joints were monitored using an optical microscope. Despite efforts, eliminating defects in the joint proved challenging, with most defects attributed to vacancies. Increasing the tool rotation speed resulted in greater mixing intensity between the aluminum and copper. The interface between the copper and aluminum was found to be prone to crack propagation. The tensile strength of the joint improved with higher tool rotation, reaching up to 88 MPa. For further analysis, stress within the joint under tensile loading was simulated.

Keywords

• dissimilar Cu/Al joint
• friction stir welding
• interface stress
• tensile failure