. Evaluation of Friction Stir Welding and Friction Stir Processing for AA 6061-T6

Abstract

Abstract Friction stir welding (FSW) is a solid state welding utilized for welded similar and dissimilar aluminum alloys which are difficult weld by traditional fusion welding processes. The current study is concerned with the study of the solid-state welding of the aluminium alloy 6061-T6 with a thickness of 4 mm. The welding tool consists of a pin with 6 mm diameter and shoulder with 16 mm diameter. The friction stir welding (FSW) was performed at different welding speeds (20, 32 and 45) mm/min as well as, a different rotational speeds (630, 1000, and 1600) rpm while the tool tilt angle was 2o with the vertical axis. The welding process was done on a traditional milling machine. The tensile test samples for were prepared by using a Water jet machine with 3 welding line angles (45o, 60o, 90o) with an applied load for both rotational and welding speeds. The tensile test was done to calculate the maximum tensile strength for all cases. The best welding efficiency was (86.43%) for a single pass (in the tensile test, all the failure occurs in advance side, at 90o orientation welding line the most failure occurs in heat affected zone (HAZ) while at 45o, 60o the most failure occurs in the region between the stir zone (SZ) and thermomechanical affected zone (TMAZ)). In this study, the Taguchi method was used to find the optimum case for all tensile tests to reduce the time and cost required when performing all tests. ANOVA analysis was also used to find the percentage contribution ratio for each factor on the maximum tensile strength, proof strength and elongation.