Ramin Delir Nazarlou - Department of Mechanical Engineering, College of Engineering, Tabriz Branch, Islamic Azad University, Tabriz, Iran
Behzad Nemati Akhgar - Mining Engineering Department, Engineering Faculty, Urmia University, P.O. Box ۵۷۵۶۱/۵۱۸۱۸ Urmia, Iran
Faraz Omidbakhsh - Department of Mechanical Engineering, College of Engineering, Tabriz Branch, Islamic Azad University, Tabriz, Iran

This paper is aimed to optimize the Friction stir welding (FSW) parameters to catch the minimum electrical resistivity and weld defects using the Taguchi based Grey Relational Analysis (GRA). FSWed sections strength and quality are affected by materials transfer, work hardening and transformations. These properties depend strongly on the materials transfer, which is under the control of welding parameters. For this purpose, ۱۰۸۰ aluminium plates were welded by the FSW process. Welding parameters were designed by Taguchi L۹ orthogonal design of the experiment. The considered variations in this process are welding speed, rotational speed, tilt angle and tool shape, which have been optimized with the GRA. The GRA and the influence of each parameter on the weld soundness were characterized. Statistical optimization technique and analysis of variance (ANOVA), was used to define each parameter's effectiveness on the defect area and electrical resistivity. The results showed that the tilt angle is the main effective parameter on the defect area and electrical resistivity variations.

Friction stir welding; Taguchi method; Grey relation analysis; Electrical resistivity; Defects area