Proceedings of the Institution of Mechanical Engineers Part B Journal of Engineering Manufacture · 2004 · 126 citations · 18 references
EngineeringMaterials EngineeringMaterials ScienceJoiningMetallic MaterialsMetallurgyAlloysFriction Stir WeldingMetalsWeldingWelding ProcessesAluminium AlloysAluminum Alloy JoiningFriction Stir Welding ProcessFriction WeldingHardnessIntermetallic Compound FormationTensile FailureWeld Nugget
The weld nugget contains coarse steel particles and Al‑Fe intermetallics within an aluminium matrix. This study shows that friction stir welding can join 6061‑T6 aluminium to AISI 1018 steel. During FSW, the aluminium melts locally and reacts with dispersed steel to form Al‑Fe intermetallics such as Al₁₃Fe₄ and Al₅Fe₂. The resulting joint is crack‑free, fails in tension at the Al‑nugget interface, and the nugget’s average hardness exceeds that of the base aluminium due to the intermetallic phases.
The present work demonstrates that friction stir welding (FSW) is a feasible route for joining 6061 aluminium (Al) alloy to AISI 1018 steel. The weld has a good weld quality and is free of cracks and porosity. The tensile failure happened at the boundary between the nugget and thermomechanically affected zone of the base Al alloy, indicating that the weld has a higher joining strength. Despite the fact that the hardness fluctuates strongly within the nugget, the average hardness of the nugget is substantially higher than that of the base Al alloy. During FSW, localized melting of the Al alloy in the nugget occurred, and the molten Al alloy reacted strongly with steel pieces spread through the nugget, which resulted in the formation of the Al-Fe intermetallic compounds, Al 13 Fe 4 and Al 5 Fe 2 . The nugget consists of secondary phases including coarse steel pieces and Al-Fe intermetallic compounds, and an Al alloy matrix. These secondary phases contribute to the hardness of the weld.
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