Numerical Simulation of the Thermo-Mechanical Behavior of 6061 Aluminum Alloy during Friction-Stir Welding

In this work, a finite-element model was elaborated to simulate the thermomechanical behavior of 6061 aluminum alloy during friction-stir welding (FSW). It was shown that FSW-induced deformation is a two-stage process. In addition to the stirring action exerted by the rotating tool probe, the material in the near-surface area of the stir zone also experienced a secondary deformation by the shoulder edge after passage of the welding tool. Both deformation steps were found to be comparable in terms of temperature and strain, but the secondary deformation was primarily concentrated in the near-surface layer. The effects of tool rotation and translation rates on FSW temperature and strain were also systematically examined. Depending on particular welding conditions, the peak welding temperature was predicted to vary from 360 to 500 °C, while the cumulative effective strain was from 12 to 45.