Impact of microstructural stability on the creep behavior of cast Al–Cu alloys
Abstract
Creep behavior of three cast Al–Cu alloys at 300 °C was studied by measuring their steady state creep rates as a function of stress. Microalloying additions in two alloys stabilized the θ' (Al2Cu) precipitates to 300 °C, which allowed grain boundary-controlled creep deformation to dominate at low stresses in these alloys. In contrast, the instability of the microstructure at 300 °C in a conventional Al–Cu 206 alloy led to the majority of θ' precipitates transform to the θ phase. The 206 alloy displayed diminished resistance to dislocation motion and a dislocation creep mechanism dominated from the lowest stresses. A modified Coble creep model was developed to describe the experimental low-stress creep rates in the alloys with thermally stable precipitate structures. Finally, it is concluded that increasing the thermal stability of precipitates in Al–Cu alloys can provide significant improvement in their creep performance.
- Authors:
-
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Colorado School of Mines, Golden, CO (United States)
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Indian Inst. of Technology, Kharagpur (India)
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Publication Date:
- Research Org.:
- Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
- Sponsoring Org.:
- USDOE Office of Energy Efficiency and Renewable Energy (EERE), Vehicle Technologies Office (EE-3V)
- OSTI Identifier:
- 1607324
- Alternate Identifier(s):
- OSTI ID: 1579764
- Grant/Contract Number:
- AC05-00OR22725
- Resource Type:
- Accepted Manuscript
- Journal Name:
- Materials Science and Engineering. A, Structural Materials: Properties, Microstructure and Processing
- Additional Journal Information:
- Journal Volume: 772; Journal Issue: C; Journal ID: ISSN 0921-5093
- Publisher:
- Elsevier
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 36 MATERIALS SCIENCE; aluminum alloys; creep; aluminum-copper; grain boundary
Citation Formats
Milligan, Brian K., Roy, Shibayan, Hawkins, Charles S., Allard Jr, Lawrence, and Shyam, Amit. Impact of microstructural stability on the creep behavior of cast Al–Cu alloys. United States: N. p., 2019.
Web. doi:10.1016/j.msea.2019.138697.
Milligan, Brian K., Roy, Shibayan, Hawkins, Charles S., Allard Jr, Lawrence, & Shyam, Amit. Impact of microstructural stability on the creep behavior of cast Al–Cu alloys. United States. https://doi.org/10.1016/j.msea.2019.138697
Milligan, Brian K., Roy, Shibayan, Hawkins, Charles S., Allard Jr, Lawrence, and Shyam, Amit. Wed .
"Impact of microstructural stability on the creep behavior of cast Al–Cu alloys". United States. https://doi.org/10.1016/j.msea.2019.138697. https://www.osti.gov/servlets/purl/1607324.
@article{osti_1607324,
title = {Impact of microstructural stability on the creep behavior of cast Al–Cu alloys},
author = {Milligan, Brian K. and Roy, Shibayan and Hawkins, Charles S. and Allard Jr, Lawrence and Shyam, Amit},
abstractNote = {Creep behavior of three cast Al–Cu alloys at 300 °C was studied by measuring their steady state creep rates as a function of stress. Microalloying additions in two alloys stabilized the θ' (Al2Cu) precipitates to 300 °C, which allowed grain boundary-controlled creep deformation to dominate at low stresses in these alloys. In contrast, the instability of the microstructure at 300 °C in a conventional Al–Cu 206 alloy led to the majority of θ' precipitates transform to the θ phase. The 206 alloy displayed diminished resistance to dislocation motion and a dislocation creep mechanism dominated from the lowest stresses. A modified Coble creep model was developed to describe the experimental low-stress creep rates in the alloys with thermally stable precipitate structures. Finally, it is concluded that increasing the thermal stability of precipitates in Al–Cu alloys can provide significant improvement in their creep performance.},
doi = {10.1016/j.msea.2019.138697},
journal = {Materials Science and Engineering. A, Structural Materials: Properties, Microstructure and Processing},
number = C,
volume = 772,
place = {United States},
year = {Wed Nov 20 00:00:00 EST 2019},
month = {Wed Nov 20 00:00:00 EST 2019}
}
Web of Science