Simulation of tensile properties of a friction stir welded Al-Si-Mg aluminum alloy

Abstract

The mechanical and microstructure properties of a friction stir welded (FSW) joint is dependent on tool design and the welding parameters. A systemic randomization and optimization of processing and welding parameters can produce welds with little or no defects with improved properties. The tensile properties of aluminum AA6082 alloy fabricated through the friction stir welding technique was simulated using the finite element model (FEM). The investigation was specifically based on the weld zone (WZ) for both the mechanical characterization and the computational modeling. The weld nugget is the region of complete deformation and recrystallization. A severe plastic deformation was experienced by the materials; hence, there is a visible microstructural evolution. The finite element modeling (FEM) of tensile properties, was computationally performed with a commercial software program, MSC MARC. The generated data was validated by the experimental results under tensile-loading conditions (i.e., maximum stress). Approximately 70 % weld strength was used as reference for the validation process while FEM was implemented under optimum processing parameters to predict the integrity of the produced welds. The maximum values of the equivalent Von Mises was approximately 12 % below the measured UTS for all the samples. This can be attributed to a strong bond between the molecules of the base metal while in solid state. A good exactness of the simulated and the experimental values validates the 3D model.