Ultimate tensile strength optimization of different FSW aluminium alloy joints

Friction stir welding (FSW) is a highly reliable joining process. However, there is still lack of optimized FSW parameters for different joint configurations. The present manuscript presents a set of optimization studies for different friction stir welding joint geometries of AA6082-T6 aluminium alloy: butt, lap and T joints. The optimization process was performed using Taguchi orthogonal arrays (OA) for designing experiments, analyses of the average effects (main effect plot) and variance (ANOVA). Welded joints were manufactured according to orthogonal arrays, selected using the Taguchi method, for each type of joint, and the ultimate tensile strength (UTS) was evaluated for statistical optimization. As a major asset for the current state of the art, this manuscript contribution is focused on the determination of the most relevant FSW parameters on UTS for a complete range of joints, as well as their interactions. In the particular case of lap and T joints, parameter optimization studies are lacking in the literature, and as such, this work aims at tackling the issue. The parameter combinations to achieve the best mechanical properties for each joint configuration were derived.