Physics Maths Engineering
Mechanical characteristics of dissimilar friction stir welding processes of aluminium alloy [AA 2024-T351 and AA 7075-T651]
Peer Reviewed
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.
Key Questions and Answers
1. What is the focus of this study?
This study investigates the mechanical and metallurgical properties of dissimilar friction stir welding (FSW) of aluminium alloys AA 2024-T351 and AA 7075-T651, evaluating the effects of welding parameters on tensile strength and yield strength.
2. Why is FSW used for aluminium alloys?
FSW is used for joining high-strength aluminium alloys like AA 2024 and AA 7075 because it avoids the defects common in traditional fusion welding methods and provides superior mechanical properties.
3. What parameters were considered in the study?
The study considered rotational speed, welding speed, and tool plunge depth to evaluate their effects on the ultimate tensile strength and yield strength of the welded joints.
4. What was the highest tensile strength achieved?
The highest tensile strength achieved was 147 MPa, using a combination of 1200 rpm rotational speed, 60 mm/min welding speed, and 0.4 mm tool plunge depth.
5. Why is FSW beneficial in aerospace manufacturing?
FSW provides improved joint characteristics, lower environmental impact, and is particularly effective in joining dissimilar materials, making it ideal for aerospace applications where high strength and durability are critical.
