Effect of friction stir welding parameters on the deep drawing of tailor-welded blanks (TWBs)

Abstract

Friction stir welding is a method for joining dissimilar sheets and producing tailor-welded blanks (TWBs). An important issue in TWBs is their formability, as the material properties is not uniform across the welding line. In this method, the mechanical properties changing is a function of welding parameters such as traverse speed, rotational speed, and the shape of the tool. A common issue is choosing proper friction welding parameters to achieve the appropriate forming properties of the welded blanks. So in this paper, TWBs of AA2024-T3 and AA7075-T6 aluminum were prepared and welded using friction stir welding (FSW) method under various conditions, including three different tool shapes as conical, cylindrical, and square under various traverse speeds and rotational speeds. Tensile tests were carried out in order to obtain the best tensile strength conditions that are acceptable for deep drawing. The deep drawing procedure was simulated by using finite element method (FEM) to investigate the effect of weld line properties on thickness distribution and weld line movement. To verify the simulation results, the best joint was subjected to the deep-drawing process and its thickness distribution and welding line movement were compared with the simulation result. The simulation results revealed that the joint made with circular pin obtain gives the best results in deep drawing in terms of thickness distribution and weld line movement.