Optimization and thermal analysis of friction stir welding on AA6061 aluminum alloys

This research focuses on the thermal analysis and optimization of FSW AA 6061 alloy joints at various welding speeds, rotational speeds, and tool geometry. Tool shoulder (concave and flat) and tool probe (tapered and cylindrical) geometries were used to weld a workpiece. The aim of this paper is to get a defect free joint by optimizing temperature using finite element analysis. A Coupled Eulerian-Lagrangian (CEL) approach on ABAQUS software was used to simulate butt joints to study thermal phenomena and defects such as tunnel, flash, and crack formation during FSW. The temperature range for welding was found via software simulation. Experimental work validated the temperature value obtained from finite element analysis. Based on the Taguchi L9 orthogonal array, nine tests were done and optimized. A Dual Laser InfraRed thermometer was used to measure the temperature of the welded workpiece. To obtain accurate results in FE, the quality of mesh was evaluated using trial and error procedures. The numerical analysis results were in good accord with the experimental data. A concave shoulder tool with tapered probe gives a defect free joint at 1000 rotational speed and 20 mm/min welding speed. The maximum temperature of 560 °C was observed when concave shoulder with tapered probe was used at 1200 rotational speed and 15 mm/min welding speed.