Mechanical properties of Al6101-T6 welds by friction stir welding and metal inert gas welding

Aluminum 6101-T6 extrusions are commonly used to distribute electricity in commercial structures due to their excellent conductivity and resistance to corrosion. When the building configuration demands a bend in the electrical pathway, the extrusions must be welded together at a 90◦ angle, forming a corner weld. The most widely used joining technique is fusion welding; however, this process typically restricts material flow in a factory due to the manual labor involved. In response, a leading manufacturer of electrical pathways, replaced their conventional Metal Inert Gas (MIG) welding with Friction Stir Welding (FSW). This investigation compared the mechanical performance of 6101-T6 corner welds produced through the FSW and MIG welding and correlated the tensile properties and fracture characteristics with the weld microstructures. FSW produced higher quality welds with superior mechanical properties that failed through typical ductile rupture. All FSW tensile specimens failed on the retreating side of the weld, and the FSW nugget revealed a consistent grain size of 10 μm to 20 μm with a non-uniform distribution of secondary phase particles creating a banded appearance.