Analysis and Multi-Response Optimization of Friction Stir Welding Parameters for Stir-Cast AA6092/B4C/ ZrO2 Hybrid Composites

In this research study, Aluminium-based alloy (AA6092) reinforced with 3 wt.% Boron Carbide (B4C) and 5 wt.% Zirconium dioxide (ZrO2) particulates was fabricated into Aluminium Metal Matrix Hybrid Composites (AMMHCs) via stir casting. These AMMHCs were subsequently friction-stir welded under various conditions to optimize the ultimate tensile strength (UTS) and weld nugget hardness (WNH) of the welded joints. This innovative AMMHC material is replacing the AA6061, and AA6082 composites for the applications like bulkhead partitions in ship hulls since this AMMHC has superior properties such as reduced weight, enhanced specific strength, and lower thermal expansion coefficient. To optimize the performance of friction stir welded butt joints in AA6092/3% B4C/5% ZrO2 composites, key Friction Stir Welding (FSW) process parameters including Tool Rotational Speed (TRS), Welding Speed (WS), Axial Load (AL) and Tool Tilt Angle (TTA) were examined. In this research work, empirical relationships were established between the most influential parameters (TRS, WS, and AL) and the resulting responses (UTS and WNH). A desirability function approach was employed to predict optimal values for UTS and WNH, leading to recommended process parameters of 1279.18 rpm for TRS, 53.54 mm/min for WS, and 4.9 kN for AL and TTA for 1.5°. The calculated UTS, and WNH values of 513.09 MPa and 194.92 HRB, respectively, were subsequently validated through experimental verification.