A 3D numerical model to investigate mechanical, thermal and material flow characteristics in friction stir welding of copper sheets

The objective of this study was to develop a numerical model for the prediction of temperature distribution, effective plastic strain distribution, and especially material flow in friction stir welding of copper plates. The DEFORM-3D software was used by incorporating a lagrangian incremental formulation. Threedimensional results of the material flow pattern which were extracted using the point tracking are in good agreement with the experiment. It was shown that the main part of material flow occurs near the top surface. Material near the top surface at the behind of tool stretches from retreating side towards advancing side which leads to non-symmetrical shape of the stir zone. The stir zone shape in FSW of copper alloys, which was predicted by simulation, does not lean completely towards any sides of welding line.