About this Abstract |
Meeting |
2020 TMS Annual Meeting & Exhibition
|
Symposium
|
Computational Materials Science and Engineering of Materials in Nuclear Reactors
|
Presentation Title |
First-principles Cluster Expansion Study of Fe and Mo Effects on Atomic Ordering in Ni-Cr Alloys |
Author(s) |
Jia-Hong Ke, Julie D. Tucker |
On-Site Speaker (Planned) |
Jia-Hong Ke |
Abstract Scope |
The development of atomic ordering in nickel-chromium alloys is of great technological interest but the non-dilute solute effect on the transformation is not well understood due to complex solute synergies. This research utilizes first-principles density functional theory (DFT), cluster expansion, and Monte Carlo simulation to explore the role of Fe and Mo in phase stability of the ordered structure. A quarternary Ni-Cr-Fe-Mo cluster expansion is constructed and the effective cluster interactions are derived based of the dataset of DFT energetics. The results show that non-dilute Mo stabilizes Ni2Cr ordering and raises the order-disorder transition temperature, while Fe produces the opposite effect. The predicted transition temperature is consistent with previous experiments. In the Monte Carlo simulation, we further investigate the preferential occupation of Fe and Mo atoms in the Ni2Cr sublattice. These results help gauge the risk of industrial alloys developing atomic ordering which increases strength but degrades ductility and toughness. |
Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |