Experimental Study on Tensile and Bending Behavior of Friction Stir Welded Butt Joints of Dissimilar Aluminum Alloys

This paper describes the feasibility of dissimilar friction stir welding (DFSW) of two different aluminum alloys; AA6101-T6 and AA6351-T6 of 6 mm plate thickness. The influence of process parameters like tool rotational speed, welding speed and axially downward force on the tensile and bending behavior of the welded plates has been studied. Weld joints were produced using EN32 tool steel with a cylindrical pin tool having 6 mm and 18 mm diameter of pin and shoulder respectively.For all the FSW joints, a constant welding speed 60mm/min was maintained andtool rotational speeds vary as of 900rpm, 1100rpm, 1300rpm and 1500 rpm respectively. From X-ray radiographs, it has been observed that joints welded at theselected process parameters gave good quality and no defects.XRD analyses were done to fmd out thepresence of mixing intermetallic compound in the FSWjoints. Transverse tensile test (as per ASTM E8 M) were performed to study the tensile strength of DFSW joints. The bending behaviors of weld joints have been conducted by three point bend test method experimentally using Universal Testing Machine.It is observed that good correlation exists between these two mechanical properties and rotational speeds. The defect free FSW butt joint produced at rotational speed 1300rpm gives the better mechanical propertiescompared to other joints.The ultimate tensile strength obtained at 1300rpm rotational speed is very close to the tensile strength of the base metals. (C) 2019 Elsevier Ltd. All rights reserved.