Structure and Properties of the Butt Joints of Annealed 1580 Alloy Sheets Made by One-Sided Friction Stir Welding

Abstract—The structure and mechanical properties of the one-sided friction stir welded butt joints of 10-mm-thick annealed sheets of a commercial grade 1580 aluminum alloy are investigated. The effect of additional water cooling of the weld zone on the microstructure and mechanical properties of the joints is studied. The strength coefficient of the joints is 0.90–0.92 of the ultimate tensile strength of the base material. Failure of the welded joints during tensile testing occurs in the thermomechanically affected zone (TMAZ) on the retreating side of the tool. The welded joints exhibit high ductility, with a bending angle of 135°–150°. Friction stir welding of annealed 1580 alloy sheets is shown to produce high-quality, defect-free welds, as confirmed by X-ray diffraction.