Optimization of microstructural and mechanical properties of friction stir welded A356 pipes using Taguchi method

In this investigation, A356 aluminum pipes were successfully welded using friction stir welding (FSW) method and the process parameters and tool design were optimized using Taguchi method. The small radius of curvature distinguishes this weld configuration geometrically from a butted plate configuration and presents unique challenges. For this reason, Deform-3D TM as a thermo-mechanically coupled, 3D FEM analysis software was used to study contact characteristics of tool and pipe. A specially-designed fixture was used to fix the welding pipes in place and then start the FSW. The rotational speed, traverse speed and tool pin shape were the parameters taken into consideration. The optimum FSW parameters were found with respect to Si particles size, hardness and ultimate tensile strength of the welded pipe.