|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Hume-Rothery Award Symposium: Alloy Phase Chemistry at the Atomic Level - Opportunities and Challenges
||First-principles Modeling of Anomalous Precipitation in W-Re Alloys under Neutron Irradiation
||Duc Nguyen-Manh, Jan S. Wrobel, Michael Klimenkov, Sergei L. Dudarev
|On-Site Speaker (Planned)
Segregation occurring in under-saturated solid solutions under irradiation is a mysterious phenomenon that potentially has significant practical implications. In this study, a new multi-scale modelling approach, based on first-principles calculations, is developed, where solute atoms and vacancies (Vac) are treated as components of a ternary alloy. The free energy of ternary W-Re-Vac alloys is evaluated as functions of temperature and vacancy concentration using effective CE interactions and quasi-canonical Monte Carlo (MC) simulations. In the low solute concentration range (< 5 at%Re), our simulations predict the formation of precipitates with Re concentration that agrees with experimental observations on self-ion irradiated W-2at.% Re alloys. Our quenched MC predictions for 1.5% Re at T=1200K show that precipitates may adopt the form of (110) faceted voids enriched by Re atoms, with the average concentration of 14%. This agrees very well with recent Transmission Electron Microscopy investigations of neutron-irradiated W samples.
||Planned: Supplemental Proceedings volume