Modelling and Simulation of Friction Stir Welding and Under Water Friction Stir Welding of Al6063 Alloy

Friction stir welding (FSW) is a solid-state welding process that is gaining importance in recent times due to better control of microstructure. In the present work, a thermo-mechanical model is developed for FSW and under water friction stir welding (UFSW) of AA 6063-T6. Temperature dependent viscosity is considered as thermo physical property along with constant values of thermal conductivity and specific heat. Fine mesh is used for complex parts of tool to obtain good results. Rotational speed of tool, feed rate and plunge pressure are taken as influencing parameters for study. Partial stick-slip boundary condition is taken between the tool and work piece interfaces. Experiments were carried out for validation of model. The results of thermal and material flow histories are extracted. Results shows the significant differences in peak temperature of FSW and UFSW along with reduction in heat affected zone in UFSW whereas results of material flow velocity underlined the differences between the FSW and UFSW in term of peak values of stir velocities with the change in influencing parameters.