Weld Formation, Microstructure, and Mechanical Properties of High-Speed Friction Stir-Welded 6061-T6 Aluminum Alloys

In this paper, 6061-T6 aluminum alloys were subjected to high-speed friction stir welding. The associated weld formation, microstructure, and mechanical properties were systematically examined via combined experimental observation and numerical simulation approaches. At a welding speed of 3000 mm/min and a rotation rate of 3800 rpm, the defect-free weld was simply achieved due to the simultaneous intense thermal input and enhanced material flow. Microstructural analysis further demonstrated a fine equiaxed grain structure featuring a predominant simple shear texture with A/A components. The resultant joint exhibited an ultimate tensile strength equivalent to 80% of the base material, accompanied by excellent fracture elongation. This research provides experimental evidence for designing high-efficiency and high-quality bonding processes for aluminum alloys.