Optimizing FSW of Aluminum and Copper alloys under guidance of modeling

Optimizing FSW of Aluminum and Copper alloys under guidance of modeling Demand for dissimilar joining of copper (Cu) and aluminum (Al) are growing because of application expansion of modern energy, transportation, and electronics systems. This dissimilar joining satisfies the conflicting requirements on high conductivity, low weight, and low cost. However, continuous joining for this hybrid structure is challenging due to the incompatibility of melting temperature, chemical reactivity and thermomechanical properties. Friction stir welding, a solid processing, poses a feasible solution to achieve desired quality, low cost and long life. Working with industrial customers and university collaborators, the team has explored dissimilar joining from different perspectives, including tool materials, processing parameters, and processing conditions. Different tool rotation speed and traverse speed are utilized. The correlated forging force and temperatures were collected and analyzed. The dissimilar joining was simulated using FEM. The results was validated by temperature profile. The residual stress and deflection results will provide guidance in processing parameter optimization. Microstructure was characterized to check if intermetallics was formed. Mechanical properties and electrical conductivity were measured to demonstrate the relationship between properties and heat input. Compared with other welding methods, FSW has the advantage in cost reduction, high efficiency, and performance enhancements. Without melting the sheets, FSW eliminates the high costs from post treatments and failures observed in other traditional welding methods, including TIG, MIG and plasma welding.