S79:E04
https://doi.org/10.3221/IGF-ESIS.79.04
Friction Stir Welding (FSW) is widely validated as a solid-state joining process that has gained significant attention for the welding of aluminum alloys in aerospace and automotive applications. In this study, the effect of Tool Pin Profiles (TPP)—Taper Threaded (TTPP), Square (SPP), and Cylindrical Threaded (CTPP)—on the flow of material, mechanical properties, corrosion properties and microstructure of dissimilar aluminum alloys AA6061-T6 and AA2024-T3 was investigated. A Taguchi L9 orthogonal array (OA) was employed for the optimization of process parameters, which included Tool Pin Profile (TPP), Tool Rotational Speed (TRS) of 600, 700, and 800 rpm and Welding Speed (WS) of 25, 30, and 35 mm/min. Mechanical properties were evaluated in terms of Ultimate Tensile Strength (UTS), Stir Zone (SZ) microhardness, and Percentage elongation. Microstructural characterization was conducted using optical microscopy and Scanning Electron Microscopy (SEM). Post weld performance was evaluated using potentiodynamic polarization and immersion corrosion tests. The TTPP condition yielded the highest measured UTS (210 MPa), SZ microhardness (162 HV), and elongation (8.89%) within the tested parameter range. This performance is attributed to improved material mixing, refined grain structure, and a favourable thermal cycle during processing. Through Taguchi optimization analysis, it was confirmed that the most favorable conditions for joining AA6061-T6 and AA2024-T3 alloys are provided by the TTPP.