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

Author(s)

Pereira, L. H. ^[1] ; Asato, G. H. ^[1] ; Otani, L. B. ^[1] ; Jorge, Jr., A. M. ^[2] ; Kiminami, C. S. ^[2] ; Bolfarini, C. ^[2] ; Botta, W. J. ^[2]

Affiliation

^[1] Univ Fed Sao Carlos, Programa Posgrad Ciencia & Engn Mat, Rod Washington Luiz, Km 235, BR-13565905 Sao Carlos, SP - Brazil

^[2] Univ Fed Sao Carlos, Dept Engn Mat, Rod Washington Luiz, Km 235, BR-13565905 Sao Carlos, SP - Brazil

• Document type: Journal article
• Source: MATERIALS CHARACTERIZATION; v. 145, p. 507-515, NOV 2018.
• Web of Science Citations: 3

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 alpha-Al-15(Fe, Mn)(3)Si-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 beta-AlFeSi as well as the typical Chinese script morphology, resulting in a final ductile microstructure, allowing further processing by hot extrusion. (AU)

• FAPESP's process: 13/05987-8 - Processing and characterization of amorphous, metastable and nano-structured metallic alloys
• Grantee: Claudio Shyinti Kiminami
• Support Opportunities: Research Projects - Thematic Grants