Coupled thermo-mechanical model based comparison of friction stir welding processes of AA2024-T3 in different thicknesses

A fully coupled thermo-mechanical finite element model was used to study the friction stir welding process of AA2024-T3 in different thicknesses. The computational results show that the material flows on the retreating and the front sides are higher. So, the slipping rates on the retreating and the front sides are lower than the ones on the trailing and advancing sides. This is the reason that the heat fluxes on the trailing and the advancing sides are higher, which leads to the fact that the temperatures are higher in this region for both thin and thick plates. The energy entering the welding plate accounts for over 50% in the total energy and about 85% in the energy comes from the frictional heat in FSW of AA2024-T3 and the balance from the mechanical effects. The stirring effect of the welding tool becomes weaker in FSW of thick plates. With consideration of the material deformations and the energy conversions, FSW of thin plates shows advantages.