Research Article

Mechanical characteristics of dissimilar friction stir welding processes of aluminium alloy [AA 2024-T351 and AA 7075-T651]

Department of Mechanical Engineering, College of Engineering, Nanotechnology Centre of Excellence, Addis Ababa Science and Technology University, P.O. Box 16417, Addis Ababa, Ethiopia

* e-mail: shiva@aastu.edu.et

Received: 27 November 2023
Accepted: 23 July 2024

Abstract

Aerospace industries have remained dependent on aluminium alloys for airframe structural components manufacturing due to their superior strength, fracture toughness, and ability to resist corrosion. Especially, AA2024 and AA7075 have been the most prominent and timely tested robust aluminium alloys in these manufacturing sectors. However, joining these aluminium alloys through conventional fusion welding is difficult. The present investigation focused on the mechanical and metallurgical properties of these high-strength dissimilar aluminium alloys 2024-T351 and 7075-T651 using a Friction Stir Welding (FSW) process. The effects of factors such as rotational speed RS (800–1200 rpm), welding speed WS (20–60 mm/min), and tool plunge depth (0.2–0.4 mm) on the ultimate tensile strength (UTS) and yield strength (YS) have been evaluated. The experimental procedure employed is based on RSM. The fractured surface morphology was investigated using SEM. The investigation result showed higher tensile strength (147 MPa) at the combination of welding parameters (1200 rpm, 60 mm/min, and 0.4 mm). The fabrication industries became the great beneficiaries of this emerging technology of the FSW.