Changing the solidification sequence and the morphology of iron-containing intermetallic phases in AA6061 aluminum alloy processed by spray forming

Journal Article · Thu Nov 15 04:00:00 EST 2018 · Materials Characterization

DOI:https://doi.org/10.1016/J.MATCHAR.2018.09.006· OSTI ID:22805874

Pereira, L. H.; Asato, G. H.; Otani, L. B. ^[1]; Jorge, Jr, A. M.; Kiminami, C. S.; Bolfarini, C.

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1. Programa de Pós-Graduação em Ciência e Engenharia de Materiais, Universidade Federal de São Carlos, Rod. Washington Luiz, Km 235, 13565-905 São Carlos, SP (Brazil)

Highlights: • Spray forming alters the solidification path of the Fe contaminated AA 6061 alloy. • Thus forming primary α-Al{sub 15}(Fe, Mn){sub 3}Si{sub 2} with polyhedral morphology • Thus preventing the formation of AlFeSi with deleterious morphology • Despite Fe contamination final microstructure presented important ductility. - Abstract: Typically, aluminum alloys are contaminated by iron during recycling cycles. Such a procedure leads to the formation of intermetallic phases with detrimental morphology, which acts as stress risers, impairing mechanical properties and consequently hindering further mechanical processing and restricting recycling. This paper aimed at studying the solidification of an AA6061 alloy highly contaminated with iron (1.4 wt%). Spray forming processing allowed altering the solidification path of the Fe-modified AA 6061 alloy, resulting in the formation of primary α-Al{sub 15}(Fe, Mn){sub 3}Si{sub 2} phase with polyhedral morphology, which traps Fe and Si at elevated temperature. Furthermore, spray forming prevented the formation of intermetallic AlFeSi phases with platelet-like morphology, such as β-AlFeSi as well as the typical Chinese script morphology, resulting in a final ductile microstructure, allowing further processing by hot extrusion.

• OSTI ID: 22805874
• Journal Information: Materials Characterization, Journal Name: Materials Characterization Vol. 145; ISSN 1044-5803; ISSN MACHEX
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ABSORPTION SPECTROSCOPY
ALUMINIUM ALLOYS
DUCTILITY
EXTRUSION
INTERMETALLIC COMPOUNDS
IRON COMPOUNDS
MICROSTRUCTURE
RECYCLING
SOLIDIFICATION
STRESSES
TRAPS