Mitigating Fe-rich intermetallic embrittlement in Al–Si–Cu–Mg alloys by deformation-assisted semi-solid rolling

초록

Reducing the CO2 footprint of aluminum supply chains requires broader use of secondary resources, yet elevated Fe impurities remain a critical barrier because Fe-rich intermetallics degrade the strength–ductility balance of Al–Si–Cu–Mg alloys. This study investigates how deformation-assisted semi-solid rolling (D-SSR) modifies Fe-rich β-Al5FeSi microstructure and the associated tensile and fracture behavior in Al–Si–Mg alloys containing 0.2 and 1.0 wt% Fe. D-SSR effectively disintegrates eutectic networks and fragments β-Al5FeSi, producing lower-aspect-ratio particles with a more homogeneous spatial distribution and altered inter-particle spacing. These microstructural changes markedly increase ultimate tensile strength by factors of 1.41 (0.2Fe) and 1.57 (1Fe) relative to the as-cast condition, with the smaller β-Al5FeSi inter-particle spacing in the 1Fe alloy providing an additional strengthening contribution. Deformation mechanism in the 0.2Fe alloy is governed by early shear-band-assisted Si cracking, whereas in 1Fe alloy is governed by particle cracking with shear bands emerging primarily at higher strain; in both cases, Overall, D-SSR substantially mitigates Fe-related embrittlement, reducing the elongation disparity between 0.2Fe and 1Fe alloys from 3.18-fold in the as-cast condition to 1.10-fold after D-SSR, establishing it as a viable pathway to achieve a competitive strength–ductility balance in high-Fe Al–Si–Cu–Mg sheet alloys. © 2026 Elsevier B.V.

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