Abstract
A dilute Al-0.02Yb-0.01Er-0.03Sc-0.03Zr (at.%) alloy was aged to create a high number density of Al3(Sc0.56Yb0.14Er0.10Zr0.20) nanoprecipitates, with 3.5 nm radius, an Yb- and Er-enriched core and Sc- and Zr-enriched shells, as measured via atom-probe tomography. At 400 °C, the alloy exhibits a 17 MPa threshold stress, 2–3 times higher than previously-studied, Sc-richer Al-0.06Sc-0.06Zr and Al-0.01Er-0.05Sc-0.06Zr (at.%) alloys with Al3(Sc,Zr) and Al3(Sc,Zr,Er) nanoprecipitates. This improvement is consistent with Yb/Er enrichment within the nanoprecipitates, increasing their lattice mismatch with the matrix.
Original language | English (US) |
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Pages (from-to) | 65-69 |
Number of pages | 5 |
Journal | Materialia |
Volume | 4 |
DOIs | |
State | Published - Dec 2018 |
Funding
This research was sponsored by Army Research Laboratory and was accomplished under Cooperative Agreement Number W911NF-10-2-0098 (Mr. V.K. Champagne, monitor). The views and conclusions contained in this document are those of the authors and should not be interpreted as representing the official policies, either expressed or implied, or the Army Research Laboratory or the U.S. Government. The U.S. Government is authorized to reproduce and distribute reprints for Government purposes notwithstanding any copyright notation herein. Useful discussions with Prof. D. Luzzi ( Northeastern University ) are acknowledged. The authors thank Mr. E. Klier ( Army Research Laboratory ) for numerous insightful discussions on the topic of rare-earth elements. Atom-probe tomography was performed at 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-1542205), and the Initiative for Sustainability and Energy (ISEN) at Northwestern University.
Keywords
- Al-Yb-Er-Sc-Zr alloy
- Atom-probe tomography
- Creep
- High-temperature alloy
- Strengthening
ASJC Scopus subject areas
- General Materials Science