An Alternative to the Recycling of Fe-Contaminated Al

Author(s)

Cante, V, Manuel ; Lima, Thiago S. ^[1] ; Brito, Crystopher ^[2] ; Garcia, Amauri ^[1] ; Cheung, Noe ^[1] ; Spinelli, Jose E. ^[3]

Affiliation

^[1] Cante, Manuel, V, Univ Estadual Campinas, UNICAMP, Dept Mfg & Mat Engn, BR-13083860 Campinas, SP - Brazil

^[2] Univ Fed Sao Paulo, UNIFESP, Marine Inst, BR-11030400 Santos, SP - Brazil

^[3] Fed Univ Sao Carlos UFSCar, Dept Mat Engn, BR-13565905 Sao Carlos, SP - Brazil

• Document type: Journal article
• Source: JOURNAL OF SUSTAINABLE METALLURGY; v. 4, n. 3, p. 412-426, SEP 2018.
• Web of Science Citations: 1

Abstract

Iron is considered an unavoidable impurity in Al-Si alloys, since it is collected during melting and casting operations. This is particularly critical when scraped and recycled materials are used. Excessive iron can reduce the mechanical properties. This is explained by the formation of Fe-bearing intermetallic particles, since the alloy properties are deeply related to their type, size, and amount within the microstructure. The effects of Ni addition on the microstructure of impure Al-Si alloys have not been established so far. As such, the present investigation examines Fe- and Fe/Ni-containing Al-9 wt% Si alloys. Two directionally solidified (DS) alloys are investigated: the Al-9 wt% Si-0.5 wt% Fe (nonmodified) and Al-9 wt% Si-0.5 wt% Fe-0.5 wt% Ni (Ni-modified) alloys. The focus is to determine solidification conditions (i.e., cooling rate, T-R; and growth rate, V-L) as well as Fe- and Fe/Ni-containing Al-9Si alloys that will yield particular volume fractions, sizes and shapes of Fe-bearing intermetallics. Considering a certain limit of the dendritic microstructure scale (i.e., lambda(1) > 100 mu m), it is shown that the ultimate tensile strength of the Al-9Si-Fe-Ni alloy is higher than that of the Al-9Si-Fe alloy and quite close to that of an Al-9Si alloy, that is, the beneficial effect of Ni addition on providing lower fraction and more compacted Fe-bearing intermetallics has counterbalanced the deleterious effect of the Fe contaminated aluminum on the tensile strength. The elongation-to-fracture, however, only approaches that of the Al-9Si alloy for the smallest lambda(1) values, which are associated with the highest solidification cooling rates. (AU)

• FAPESP's process: 16/10596-6 - Impulse Atomization of Sn-Zn and Al-Si alloys: correlations between microstructures/morphologies and processing parameters
• Grantee: José Eduardo Spinelli
• Support Opportunities: Scholarships abroad - Research
• FAPESP's process: 15/11863-5 - Microstructure evaluation of ternary Al-Si-Cu, Sn-Bi-Sb and Zn-Sn-Cu and its correlations with mechanical properties
• Grantee: José Eduardo Spinelli
• Support Opportunities: Regular Research Grants
• FAPESP's process: 17/12741-6 - Application of experimental solidification techniques, characterization of microstructure and properties in the evaluation of eutectic and hypereutectic Al-base and Zn-base alloys
• Grantee: José Eduardo Spinelli
• Support Opportunities: Regular Research Grants
• FAPESP's process: 17/16058-9 - Solidification Microstructures and Wear Resistance of Zn-Al-Bi Monotectic Alloys
• Grantee: Noe Cheung
• Support Opportunities: Scholarships abroad - Research