Making sustainable aluminum by recycling scrap: The science of “dirty” alloys

Dierk Raabe, Dirk Ponge, Peter J. Uggowitzer, Moritz Roscher, Mario Paolantonio, Chuanlai Liu, Helmut Antrekowitsch, Ernst Kozeschnik, David Seidmann, Baptiste Gault, Frédéric De Geuser, Alexis Deschamps, Christopher Hutchinson, Chunhui Liu, Zhiming Li, Philip Prangnell, Joseph Robson, Pratheek Shanthraj, Samad Vakili, Chad SinclairLaure Bourgeois, Stefan Pogatscher

Publikation: Beitrag in FachzeitschriftÜbersichtsartikelBegutachtung

4 Zitate (Scopus)

Abstract

There are several facets of aluminum when it comes to sustainability. While it helps to save fuel due to its low density, producing it from ores is very energy-intensive. Recycling it shifts the balance towards higher sustainability, because the energy needed to melt aluminum from scrap is only about 5% of that consumed in ore reduction. The amount of aluminum available for recycling is estimated to double by 2050. This offers an opportunity to bring the metallurgical sector closer to a circular economy. A challenge is that large amounts of scrap are post-consumer scrap, containing high levels of elemental contamination. This has to be taken into account in more sustainable alloy design strategies. A “green aluminum” trend has already triggered a new trading platform for low-carbon aluminum at the London Metal Exchange (2020). The trend may lead to limits on the use of less-sustainable materials in future products. The shift from primary synthesis (ore reduction) to secondary synthesis (scrap melting) requires to gain better understanding of how multiple scrap-related contaminant elements act on aluminum alloys and how future alloys can be designed upfront to become scrap-compatible and composition-tolerant. The paper therefore discusses the influence of scrap-related impurities on the thermodynamics and kinetics of precipitation reactions and their mechanical and electrochemical effects; impurity effects on precipitation-free zones around grain boundaries; their effects on casting microstructures; and the possibilities presented by adjusting processing parameters and the associated mechanical, functional and chemical properties. The objective is to foster the design and production of aluminum alloys with the highest possible scrap fractions, using even low-quality scrap and scrap types which match only a few target alloys when recycled.
OriginalspracheEnglisch
Aufsatznummer100947
Seitenumfang150
FachzeitschriftProgress in materials science
Jahrgang128.2022
AusgabenummerJuly
DOIs
PublikationsstatusElektronische Veröffentlichung vor Drucklegung. - 7 Apr. 2022

Bibliographische Notiz

Funding Information:
C.H.L. acknowledges financial support from the National Natural Science Foundation of China (No. U2032117). Z.L. would like to acknowledge special funding from the Construction of Innovative Hunan Province of China (2019RS1001). D.N.S. acknowledges the support of the Northwestern University Center for Atom-Probe Tomography (NUCAPT). The LEAP tomograph at NUCAPT was purchased and upgraded with grants from the NSF-MRI (DMR-0420532) and ONR-DURIP (N00014-0400798, N00014-0610539, N00014-0910781, N00014-1712870) programs. NUCAPT received support from the MRSEC program (NSF DMR-1720139) at the Materials Research Center, the SHyNE Resource (NSF ECCS-2025633), and the Initiative for Sustainability and Energy (ISEN) at Northwestern University. The research on aluminum alloys was supported by the Office of Naval Research, Dr. William M. Mullins, grant officer. D.N.S. is grateful to D. Isheim for managing the atom probe tomography center at Northwestern University. P.B.P. and J.D.R. thank the EPSRC, LightForm Programme grant, (EP/R001715/1) for supporting aspects of this work. S.P. gratefully acknowledges financial support from the Austrian Federal Ministry for Digital and Economic Affairs, the National Foundation for Research, Technology and Development and the Christian Doppler Research Association. E.K. gratefully acknowledges financial support from the Austrian Federal Government (in particular from Bundesministerium für Verkehr, Innovation und Technologie and Bundesministerium für Wissenschaft, Forschung und Wirtschaft) represented by Österreichische Forschungsförderungsgesellschaft mbH and the Styrian and the Tyrolean Provincial Government, represented by Steirische Wirtschaftsförderungsgesellschaft mbH and Standortagentur Tirol, within the framework of the COMET Funding Programme. L.B. acknowledges the use of the instruments and scientific and technical assistance at the Monash Centre for Electron Microscopy, a Node of Microscopy Australia. This research used equipment funded by Australian Research Council grant LE0454166.

Funding Information:
C.H.L. acknowledges financial support from the National Natural Science Foundation of China (No. U2032117). Z.L. would like to acknowledge special funding from the Construction of Innovative Hunan Province of China (2019RS1001). D.N.S. acknowledges the support of the Northwestern University Center for Atom-Probe Tomography (NUCAPT). The LEAP tomograph at NUCAPT was purchased and upgraded with grants from the NSF-MRI (DMR-0420532) and ONR-DURIP (N00014-0400798, N00014-0610539, N00014-0910781, N00014-1712870) programs. NUCAPT received support from the MRSEC program (NSF DMR-1720139) at the Materials Research Center, the SHyNE Resource (NSF ECCS-2025633), and the Initiative for Sustainability and Energy (ISEN) at Northwestern University. The research on aluminum alloys was supported by the Office of Naval Research, Dr. William M. Mullins, grant officer. D.N.S. is grateful to D. Isheim for managing the atom probe tomography center at Northwestern University. P.B.P. and J.D.R. thank the EPSRC, LightForm Programme grant, (EP/R001715/1) for supporting aspects of this work. S.P. gratefully acknowledges financial support from the Austrian Federal Ministry for Digital and Economic Affairs, the National Foundation for Research, Technology and Development and the Christian Doppler Research Association. E.K. gratefully acknowledges financial support from the Austrian Federal Government (in particular from Bundesministerium für Verkehr, Innovation und Technologie and Bundesministerium für Wissenschaft, Forschung und Wirtschaft) represented by Österreichische Forschungsförderungsgesellschaft mbH and the Styrian and the Tyrolean Provincial Government, represented by Steirische Wirtschaftsförderungsgesellschaft mbH and Standortagentur Tirol, within the framework of the COMET Funding Programme. L.B. acknowledges the use of the instruments and scientific and technical assistance at the Monash Centre for Electron Microscopy, a Node of Microscopy Australia. This research used equipment funded by Australian Research Council grant LE0454166. Several of the authors express their sincere thanks for inspiring discussions about sustainable aluminum with companies such as AMAG, Hydro and Alcoa.

Publisher Copyright:
© 2022 The Authors

Dieses zitieren