Effects of friction stir welding tool tilt angle on properties of Al-Mg-Si alloy T-joint

• DOI: 10.1016/j.cirpj.2021.03.015
• Publication Date: 2021-04-30T23:37:10Z
• Authors: Hesamoddin Aghaja...; Naser Kordani; Hamed Aghajani De...
• Keywords: Flange; Friction Stir Welding

Abstract Friction stir welding tool tilt angle (TTA) is a vital parameter that influences the final joint quality. The underlying mechanism of TTA in T configuration joints has not been fully understood. In this research, the computational fluid dynamic method is implemented to investigate the effects of TTA on the study of thermal history, materials velocity, strain rate, and viscosity changes of Al-Mg-Si alloy. The critical issue in T-configuration joints is the interaction between flange and skin. This interaction should optimize the mixing pattern of flange and skin to obtain the strongest joint. Various range of TTA on heat transfer and stirring action between skin and flange are investigated. Material flow, microstructure changes, and tensile strength of joint assessed. Based on the obtained results, by increasing TTA, a higher temperature is generated on the advancing side (AS). It is attributed to the insufficient materials stirring action at lower TTA on the interface of skin and flange leads to incomplete joint formation. With increasing TTA, frictional and axial forces are increased but over stirring action leads to the formation of surface flash and tunnel defect in the skin-flange interface. This study’s results can be used for the application of TTA in the FSW of T-joint configurations.