Akademik Veri Yönetim Sistemi
ARABIAN JOURNAL FOR SCIENCE AND ENGINEERING, 2025 (SCI-Expanded, Scopus)
This study focuses on the friction stir welding of AA 5754-H111 alloy, emphasizing the impact of traverse speed, tool rotational speed, and pin positioning strategy (direct vs. overlapping) on the formation of robust weld bonds. The welding process employed a tapered-helical threaded pin profile. Weld quality was evaluated through tensile testing, hardness measurements, and macrostructural evaluations to assess strength, ductility, and defect formation. The results revealed that a rotational speed of 500 rpm yielded superior mechanical properties compared to 800 rpm, at which excessive heat input promoted defect formation and compromised the integrity of the weld. The highest ultimate tensile strength of 224.4 +/- 1.2 MPa was obtained in the overlapped weld joint produced at 100 mm/min, demonstrating a slight improvement compared to the corresponding direct weld (223.7 +/- 1.3 MPa). The overlapping weld joint configuration also enhanced elongation, particularly at 500 rpm and 80 mm/min, where elongation increased from 18.6 +/- 2.7% (direct) to 23.5 +/- 4.7% (overlapping), representing a 26% improvement. In contrast, at 800 rpm, the welded joints exhibited a substantial reduction in ultimate tensile strength, dropping as low as 170.4 +/- 20.7 MPa, with elongation decreasing to 8.6 +/- 2.3%, indicating the adverse effects of excessive heat input and material softening. Microstructural analysis identified onion ring patterns in the nugget zone, indicating localized thermal fluctuations. In addition, corrosion tests were carried out under accelerated aging conditions; it was revealed that overlapped welds offered better corrosion resistance than direct welds. These findings emphasize the importance of process parameter optimization and weld seam configuration in improving the mechanical integrity and corrosion resistance of friction stir-welded AA 5754-H111 joints.