Optimizations of friction stir welding parameters with Taguchi method for the maximum electrical conductivity in Al-1080 welded sections

In this paper, an attempt has been made to optimize the welding parameters. FSWed sections strength and quality is affected by materials transfer, work hardening and transformations. These properties depends strongly on the materials transfer, which is under the control of welding parameters. The soundness of friction stir welded sections usually studied by NDT techniques. However, it could be characterized by physical properties such as electrical conductivity. As the higher electrical conductivity, means lower defects and higher welding quality. For this purpose, the Taguchi L9 orthogonal design of experiment was used to optimize the welding parameters. The optimum process parameters and their effectiveness on the electrical conductivity of welded sections were analyzed by S/N ratio and ANOVA tests. The results indicated that the tilt angle and tool shape are the most influential parameters to catch the maximum conductivity in welded joints. The optimum tool shape and tilt angle are cylindrical and 3º. The optimum conditions for welding speed and rotational speed were obtained as following; 100 mm/min and 900 rpm in stir zone, 250 mm/min and 900 rpm in advancing side (AS) and 100 mm/min and 450 rpm in Retreating side (RS), respectively.