Parametric finite-element studies on the effect of tool shape in friction stir welding

Abstract

The success of the friction-stir-welding (FSW) process, and the weld quality produced, depends significantly on the design of the welding tool. In this paper the effects of variation in various tool geometry parameters on FSW process outcomes, during the plunge stage, were investigated. Specifically the tool shoulder surface angle and the ratio of the shoulder radius to pin radius on tool reaction force, tool torque, heat generation, temperature distribution, and size of the weld zone were investigated. The studies were carried out numerically using the finite-element method. The welding process used AA2024 aluminium alloy plates with a thickness of 3 mm. It was found that, in the plunge stage, the larger the pin radius, the higher force and torque the tool experiences and the greater the heat generated. It was also found that the shoulder angle has very little effect on energy dissipation or on temperature distribution.