Experimental Investigation on Strength of Friction Stir Welded Al 6061-T6 Alloy Joints with Varying Oblique Angle

The friction stir welding, abbreviated as FSW, is an innovative solid-state welding process widely used for welding of different metals and their alloys, particularly aluminum and its alloys, in various industries including aerospace and automotive. The tensile properties such as strength under tension of friction stir butt welded joints of Al 6061-T6 alloy sheets under the variable welding (oblique) angle 0°, 30° and 60° are experimentally investigated. The Taguchi L9 experimental method is chosen to construct the numbers of welding experiment. The friction stir welding is performed by considering the process parameters such as rotational speed, tilt angle and feed. The probe is chosen as circular. The operating ranges of process parameters are rotational speed 560, 900 and 1400 rpm, tilt angle 0°, 0.5° and 1° and feed rate 20, 63 and 100 mm/min. The highest strength under tension is obtained as 316 MPa, when the rotational speed is 560 rpm, tilt angle 0.5° and feed rate 63 mm/min. An empirical relationship is generated between the obtained weld joint strength and chosen process parameters. The most effective process parameter is suggested as rotational speed by conducting the regression and ANOVA analysis.