Abstract
Binary Al-Sc alloys have excellent strength at room and elevated temperature up to 300°C due to coherent of Al3Sc nanoprecipitates. Binary Al-Ni alloys are an alternative alloy for high-temperature applications owing to high-thermal stability of Al3Ni microfibers. In this study, the hardness evolution at 300°C for up to 672 h for eutectic ternary Al-6Ni-0.4Sc (wt%) was studied and compared with binary Al-0.4Sc and Al-6Ni alloys. The Al-6Ni alloy maintains a constant hardness after aging at 300°C up to 672 h. Both Al-0.4Sc and Al-6Ni-0.4Sc alloys show strong precipitation strengthening response, with peak hardness reached after about 3 h aging, due to Al3Sc precipitates. These precipitates were studied in Al-6Ni-0.4Sc via local electrode atom probe tomography and contain small amounts of Ni (0.04 at%) which do not affect the kinetics of precipitation. The microhardness evolution for Al-6Ni-0.4Sc can be explained through superposition of binary Al-0.4Sc and Al-6Ni alloys, indicating that both Al3Sc nanoprecipitates and Al3Ni microfibers contribute to strength.
Original language | English (US) |
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Pages (from-to) | 37-41 |
Number of pages | 5 |
Journal | Journal of Metals, Materials and Minerals |
Volume | 29 |
Issue number | 2 |
DOIs | |
State | Published - 2019 |
Funding
CS acknowledges the support of King Mongkut’s University of Technology Thonburi through the “Petchra Pra Jom Klao Doctoral Scholarship” [Grant No. 01/2557]. Financial support from the “KMUTT 55th Anniversary Commemorative Fund” and the National Research Council of Thailand are acknowledged. The authors sincerely thank Prof. David N. Seidman (Northwestern University) for useful discussions, and the use of 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. DCD has financial interests relative to NanoAl, LLC, a company developing and marketing new aluminum alloys.
Keywords
- Al-Ni-Sc alloy
- Atom probe tomography
- Precipitation strengthening
ASJC Scopus subject areas
- Ceramics and Composites
- Biomaterials
- Materials Science (miscellaneous)
- General Materials Science
- Polymers and Plastics
- Metals and Alloys