Abstract
A scientific question vitally important to the materials community is whether there exist "self-assembled" nanoclusters that are thermodynamically stable at elevated temperatures. Using in situ neutron scattering, we have characterized the structure and thermal stability of a nano-structured ferritic alloy. Nanometer sized nanoclusters were found to persist up to ∼1400 °C, providing direct evidence of a thermodynamically stable alloying state for the nanoclusters. High-temperature neutron diffraction measurements show a stable ferritic matrix, with little evidence of recrystallization or grain growth at temperatures up to 1300 °C. This result suggests that thermally stable nanoclusters and the oxygen-vacancy interaction limit the diffusion of Fe atoms and hence the mobility of grain boundaries, stabilizing the microstructure of the ferritic matrix at high temperatures.
| Original language | English |
|---|---|
| Pages (from-to) | 96-101 |
| Number of pages | 6 |
| Journal | Journal of Alloys and Compounds |
| Volume | 529 |
| DOIs | |
| State | Published - Jul 15 2012 |
Funding
Research sponsored by the Materials Sciences and Engineering Division, Office of Basic Energy Sciences, US Department of Energy . Atom probe tomography (MKM) was supported by ORNL's Shared Research Equipment (SHaRE) User Facility, which is sponsored by the Office of Basic Energy Sciences, US Department of Energy. The Spallation Neutron Source was operated with support from the Scientific User Facilities Division, Office of Basic Energy Sciences, US Department of Energy. We thank Dr. D.T. Hoelzer for providing the 14YWT samples for this study.
| Funders | Funder number |
|---|---|
| Scientific User Facilities Division | |
| U.S. Department of Energy | |
| Basic Energy Sciences | |
| Oak Ridge National Laboratory | |
| Division of Materials Sciences and Engineering |
Keywords
- Atom probe tomography (APT)
- High temperature deformation
- Nanostructure
- Neutron diffraction
- Small angle neutron scattering