About this Abstract |
Meeting |
2021 TMS Annual Meeting & Exhibition
|
Symposium
|
Accelerated Discovery and Qualification of Nuclear Materials for Energy Applications
|
Presentation Title |
Molecular Dynamics Study of Cascade Overlap Effects in FCC Ni |
Author(s) |
Samuel Morris, Brian Wirth |
On-Site Speaker (Planned) |
Samuel Morris |
Abstract Scope |
Neutron or self-ion irradiation of Ni-base FCC alloys leads to nucleation of immobile Frank dislocation loops. With increasing dose, cascade overlap may play an important role in the microstructural evolution of these alloys. We use molecular dynamics to simulate cascade overlap with existing defects in FCC Ni at various geometries and cascade energies. We study cascade overlap with interstitial and vacancy Frank loops, as well as cavities. We also simulate cascades in defect-free Ni as a benchmark to assess how cascade overlap affects primary damage formation. We find that existing defects may shrink, change Burgers vector, or possibly recombine with in-cascade point defects and subsequently nucleate one or more new defects following cascade quench. However, interstitial Frank loops may grow if overlapped by the interstitial-rich cascade periphery, likely due to loops acting as biased sinks for interstitials. This work should inform multiscale modeling of high-dose irradiation of Ni-base alloys. |
Proceedings Inclusion? |
Planned: |
Keywords |
Modeling and Simulation, Nuclear Materials, Computational Materials Science & Engineering |