Modelling, Temperature Analysis, and Mechanical Properties of Friction Stir Welding of Al-Cu Joints with Hardened OHNS Steel Tools

Friction stir welding (FSW) is a nearly modern welding method with vital advantages over the conventional welding process, such as lower distortion, enhanced mechanical properties, and eco- friendly. In FSW, the joint characteristics mainly depend on heat development during the joining process due to its solid-state joining method. The basic principles of thermomechanical methods during FSW are unknown since it is a new metal joining method. In this investigation, the 2D and 3D models of the tools with different pin forms were designed using SOLIDWORKS. The ANSYS software was used to investigate the temperature distributions near the weld zones. The fixture was designed and made according to the machine conditions. The base plates used were AA6101 and C11000; the tool material used was the Hardened OHNS steel tool with square and circular pin form. The temperature values were measured in each trial while joining of Al-Cu base plates along the weld line. The results reveal that in the joint area, a trial with high temperature leads to high ultimate tensile strength (UTS) and Charpy impact strength (CIS). Made at tool rotation speed 1200 rpm and feed velocity 20 mm/min of Hardened OHNS steel tool with circular pin form. The obtained UTS value at joints was less than that of Al and Cu base plates. The microhardness value detected at the joint area was higher than the Al and Cu base plates, providing high strength, and irregularly dispersed.