Friction stir welding parameter optimization for dissimilar AA2014 and AA5052 aluminium alloys

Area of Science:

• Materials Science
• Mechanical Engineering
• Manufacturing Processes

Background:

• Friction Stir Welding (FSW) is a solid-state joining process.
• Joining dissimilar aluminum alloys presents challenges in achieving optimal mechanical properties.
• Optimizing FSW parameters is crucial for defect-free welds and enhanced performance.

Purpose of the Study:

• To optimize Friction Stir Welding (FSW) parameters for dissimilar aluminum alloys AA2014 and AA5052.
• To investigate the influence of key processing variables on weld mechanical properties.
• To achieve a balance of high ultimate tensile strength (UTS), yield strength (YS), and microhardness.

Main Methods:

• Utilized Response Surface Methodology (RSM) with a Box-Behnken Design (BBD).
• Systematically varied tool rotating speed, pin geometry, axial load, and welding speed.
• Employed multi-response optimization using the desirability function for parameter selection.

Main Results:

• Identified optimal FSW conditions: 1879.95 rpm, square pin, 10 kN axial load, 17.62 mm/min welding speed.
• Achieved a balanced mechanical performance with UTS = 257.76 MPa, YS = 196.96 MPa, and microhardness = 100.96 Hv.
• Validation experiments confirmed model reliability with prediction errors below 1.5% for UTS and YS.

Conclusions:

• The integrated RSM-BBD-desirability approach effectively optimized FSW for dissimilar aluminum alloys.
• Optimized welds exhibited fine, equiaxed grain structures and homogeneous precipitate distribution, leading to superior mechanical properties.
• The developed method produces defect-free joints with an improved strength-hardness balance for lightweight structural applications.