Abstract
We demonstrate that a small addition of a low-melting point element such as Sn (0.02 at.%), within the impurity tolerances of commercial aluminum alloys, to an Al-0.5Mn-0.3Si (at.%) model alloy, converts this non-heat-treatable (with negligible precipitation strengthening) alloy into a heat-treatable (precipitation strengthened) alloy with high strength, creep, and coarsening resistance. The small Sn additions refine significantly the α-Al(Mn,Fe)Si-precipitate distribution, which is related primarily to the formation of Sn-rich nanoprecipitates at intermediate temperatures (~200 °C). At higher temperatures, these nanoprecipitates act as heterogeneous nucleation sites for Mn-Si-rich nanoprecipitates—the quasi-crystalline precursors of the α-precipitate. We demonstrate that precipitation hardening by these Sn-modified α-precipitates is a highly efficient approach for designing creep-resistant aluminum alloys.
Original language | English (US) |
---|---|
Title of host publication | Light Metals 2023 |
Editors | Stephan Broek |
Publisher | Springer Science and Business Media Deutschland GmbH |
Pages | 528-534 |
Number of pages | 7 |
ISBN (Print) | 9783031225314 |
DOIs | |
State | Published - 2023 |
Event | Light Metals Symposium held at the TMS Annual Meeting and Exhibition, TMS 2023 - San Diego, United States Duration: Mar 19 2023 → Mar 23 2023 |
Publication series
Name | Minerals, Metals and Materials Series |
---|---|
ISSN (Print) | 2367-1181 |
ISSN (Electronic) | 2367-1696 |
Conference
Conference | Light Metals Symposium held at the TMS Annual Meeting and Exhibition, TMS 2023 |
---|---|
Country/Territory | United States |
City | San Diego |
Period | 3/19/23 → 3/23/23 |
Funding
Acknowledgements This research was supported by the Office of Naval Research (N00014-18-1-2550 and N00014-21-1-2782) with Dr. W.M. Mullins and Dr. J. Wolk serving as the grant officers. We are grateful to research associate Prof. Dieter Isheim, Northwestern University (NU), for numerous valuable discussions of the APT experiments. Atom-probe tomography was performed at the North-western 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 Northwestern’s Materials Research Center, the SHyNE Resource (NSF ECCS-1542205), and the Initiative for Sustainability and Energy (ISEN). This research made use of the Materials Characterization and Imaging Facility (MatCI), which receives support from the MRSEC Program (NSF DMR-1720139) of the Materials Research Center at NU. This work made use of the EPIC facility of the NUANCE Center, which receives support from the MRSEC program NSF DMR-1720139) at the Materials Research Center; the International Institute for Nanotechnology (IIN NIH-S10OD026871); and the State of Illinois, through the IIN. DNS and DCD disclose financial interests in Unity Aluminum (formerly Braidy Industries), which is active in aluminum R&D.
Keywords
- Creep resistance
- Heterogeneous nucleation
- High-temperature aluminum alloys
- Precipitation strengthening
- Tin micro-alloying
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Energy Engineering and Power Technology
- Mechanics of Materials
- Metals and Alloys
- Materials Chemistry