Optimization of FSW Parameters to Improve the Mechanical Properties of AA2024-T351 Similar Joints Using Taguchi Method

Friction Stir Welding(FSW) was carried out on commercially available Aluminum Alloy 2024-T351 plates with dimensions of 100×100×6.35 mm. Design of experiment (DOE) was applied to determine the most important factors which influence Ultimate Tensile Strength (UTS) and hardness of AA 2024 T-351 joints produced by Friction Stir Welding (FSW). Effect of three factors which include tool rotational speed, welding speed and tool tilt angle on UTS and hardness were investigated. By Taguchi method using L9 orthogonal array, the optimum of process parameters was determined. ANOVA analysis was carried out to determine the percentage contribution of each factor on Tensile Strength and Hardness. Tensile strength of welded joints increased with increasing in rotational speed from 355rpm to 560 rpm, traverse speed from 12.5mm/min to 20 mm/min but further increase in the rotational speed from 560rpm to 900rpm decreased the tensile strength of the joints. Hardness value increased with increasing rotational speed, traverse speed and a tool tilt angle of 0 and 1 degree.