Abstract
The development of revolutionary new alloys and composites is crucial to meeting materials requirements for next generation nuclear reactors. The newly developed amorphous silicon oxycarbide (SiOC) and crystalline Fe composite system has shown radiation tolerance over a wide range of temperatures. To advance understanding of this new composite, we investigate the structure and thermal stability of the interface between amorphous SiOC and crystalline Fe by combining various experimental techniques and simulation methods. We show that the SiOC/Fe interface is thermally stable up to at least 400 °C. When the annealing temperature reaches 600 °C, an intermixed region forms at this interface. This region appears to be a crystalline phase that forms an incoherent interface with the Fe layer. Density functional theory (DFT) Molecular dynamics (MD) is performed on the homogeneous SiFeOC phase to study the early stages of formation of the intermixed layer. Both experimental and simulation results suggest this phase has the fayalite crystal structure. The physical processes involved in the formation of the intermixed region are discussed.
| Original language | English |
|---|---|
| Pages (from-to) | 61-67 |
| Number of pages | 7 |
| Journal | Acta Materialia |
| Volume | 135 |
| DOIs | |
| State | Published - Aug 15 2017 |
| Externally published | Yes |
Funding
We acknowledge financial support from the DoE Office of Nuclear Energy, Nuclear Energy Enabling Technologies, award DE-NE0000533. The research was performed in part an the Nebraska Nanoscale Facility: National Nanotechnology Coordinated Infrastructure and the Nebraska Center for Materials and Nanoscience, which are supported by the National Science Foundation, Award ECCS: 1542182, and by the Nebraska Research Initiative. Use of the Advanced Photon Source was supported by the US. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357. The work at the National Synchrotron Light Source-II, Brookhaven National Laboratory, was supported by the US. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-SC0012704. This work has benefited from the use of the Asterix reflectometer at the Lujan Center at Los Alamos Neutron Science Center. Los Alamos National Laboratory is operated by Los Alamos National Security LLC under DOE Contract DE-AC52-06NA25396. H. Ding acknowledges computational resources provided by the DOE-National Energy Research Scientific Computing Center under contract No. DE-AC02-05CH11231 and by the Texas A&M High Performance Research Computing program.
Keywords
- Amorphous silicon oxycarbide
- Amorphous/crystalline interface
- Nanocrystalline Fe
- Thermal stability