|About this Abstract
||2016 TMS Annual Meeting & Exhibition
||Nanostructured Materials for Nuclear Applications
||The Roles of Oxide Interfaces and Grain Boundaries in Helium Management in Nano-structured Ferritic Alloys: A First Principles Study
||Yong Jiang, Litong Yang, Jian Xu, G. Robert Odette, Yuan Wu, Takuya Yamamoto, Zhangjian Zhou, Zheng Lu
|On-Site Speaker (Planned)
Nano-size Y-Ti-oxides are largely responsible for the extraordinary mechanical properties of nano-structured ferritic alloys (NFAs). Here we report a theoretical study for assessing the possible roles of the ferrite/oxide interface in managing helium in NFAs. Using one observed cube-on-cube orientation relationship, various candidate structures of the ferrite/Y2Ti2O7 interfaces are constructed and the associated energies are carefully evaluated. The interface phase diagram is obtained by expressing the interface energy as a function of temperature and internal oxygen activity (in terms of oxygen partial pressure). The oxide interfaces are predicted as Y/Ti-rich at thermodynamic equilibrium for the wide temperature range of interest. Vacancies and helium both tend to segregate to the interfaces, in preference to iron grain boundaries. Combined with our previous results on bulk-phase Y2Ti2O7, the profound implication of nano-oxides to helium management in NFAs is discussed.
||Planned: A print-only volume