Effect of FSW parameters on residual stress, microstructure and mechanical performance of dissimilar 7075/2017A Al joints

Trdan, Uroš (avtor), Drev, Sandra (avtor), Klobčar, Damjan (avtor), Berlec, Tomaž (avtor), Ravnikar, Dunja (avtor)

This study investigates the effects of friction stir welding (FSW) parameters on residual stresses, microstructural evolution, hardness distribution, and tensile behaviour of dissimilar Al 7075-T651/Al 2017A-T451 joints. Three welding conditions with different welding ratios were analysed to clarify the role of heat input and material flow on joint performance. Residual stress measurements revealed asymmetric distributions typical of dissimilar FSW, with “M-shaped” longitudinal profiles and tensile stresses concentrated in the nugget zone. Lowest welding ratio (1.66 rev/mm) resulted in reduced tensile residual stresses and improved stress uniformity. Microstructural analyses showed sound weld formation with refined nugget-zone grains (∼2.5 – 3.5 μm), high-angle grain boundaries, and high dislocation density structures, indicating dynamic recrystallization dominated by severe plastic deformation. Thermally stable Al–Fe–Mn–Si-rich dispersoids persisted in the nugget zone, whose microstructure closely resembled that of the AA2017A base material, consistent with the dominance of the advancing-side alloy within the nugget zone. The optimal welding condition achieved the highest strength and ductility (Rp▫$_{0.2}$▫ = 304 ± 3 MPa, R▫$_{m}$▫ = 421 ± 2 MPa, A▫$_{t}$▫ = 8.4 ± 0.6%) and the 3-4 times lower weld-line heterogeneity Ψ compared to other conditions (e.g., Ψ–R▫$_{m}$▫: 0.98% vs. 3.47%), confirming enhanced mechanical uniformity. These results demonstrate that appropriate FSW parameter selection and precipitation stability are critical for producing structurally reliable dissimilar aluminium joints.

• Jezik: Angleški jezik
• Ključne besede: friction stir welding, FSW, high-strength dissimilar aluminium alloy, microstructure, microhardness, XRD residual stresses
• Vrsta gradiva: Članek v reviji
• Tipologija: 1.01 - Izvirni znanstveni članek
• Organizacija: FS - Fakulteta za strojništvo
• Status publikacije: Objavljeno
• Različica publikacije: Objavljena publikacija
• Leto izida: 2026
• Št. strani: Str. 5359-5373
• Številčenje: Vol. 42
• PID: 20.500.12556/RUL-182195
• UDK: 621.791:669.715
• ISSN pri članku: 2238-7854
• DOI: 10.1016/j.jmrt.2026.04.136
• COBISS.SI-ID: 276723459
• Datum objave v RUL: 29.04.2026

Gradivo je del revije

• Naslov: Journal of Materials Research and Technology
• Skrajšan naslov: J. Mater. Res. Technol.
• Založnik: Elsevier
• ISSN: 2238-7854
• COBISS.SI-ID: 519699737

Licence

• Licenca: CC BY 4.0, Creative Commons Priznanje avtorstva 4.0 Mednarodna
• Povezava: http://creativecommons.org/licenses/by/4.0/deed.sl
• Opis: To je standardna licenca Creative Commons, ki daje uporabnikom največ možnosti za nadaljnjo uporabo dela, pri čemer morajo navesti avtorja.

Sekundarni jezik

• Jezik: Slovenski jezik
• Ključne besede: varjenje z gnetenjem, FSW, aluminijeve zlitine, mikrostruktura, mikrotrdota, rentgenska difrakcija