Modelling and Analysis of High Strain Rate Deformation at Elevated Temperature in Friction Stirring of Aluminum Alloys

Friction stirring is a fundamental process in the friction stir welding (FSW), and moreover, high strain rate deformation in elevated temperature to lead to extremely high ductility and fine grain size. In the present study, friction stirring process has been successfully modelled as a high temperature deformation depending on strain rate and temperature, assuming shear deformation of material in stir zone and generation of frictional heat by rotating tool. Axial load and torque during the process were estimated based on the model, and compared with the experimental data at two kinds of combination ratio in FSW of aluminum and Al-Mg alloy. It was, consequently, confirmed that the model could evaluate flow stress and strain rate from the experimental load and torque.