Appropriate Parameters for Preheat Friction Stir Welding of 6061-T6 Aluminum Alloys Using Taguchi Method

Friction stir welding (FSW) refers to a solid-state welding method specifically used for joining low-melting-point metals that yields an exceptionally strong joint and low thermal distortion. There are various conditions and factors in FSW which have the effect on weld quality such as rotational speed and plunge rate. This research project is focused on determining the optimal parameters of the FSW process on aluminum sheets grade 6061-T6, using CNC as the main welding machine. The design of experiments employed the Taguchi method, using two essential welding parameters: rotation speed (RPM) and welding speed (mm/min). The ultimate tensile strength and microhardness values (Vickers) of a welding joint from each experiment were used to find the optimal welding conditions. The experimental results show that FSW of the two aluminum sheets with the rotational speed of 1750 RPM and welding speed of 900 mm/min yields the highest mechanical properties of the weldment having the ultimate tensile strength of 304.29 MPa and microhardness (Vickers) of 74.12 HV.