**About this Abstract** |

**Meeting** |
**2016 TMS Annual Meeting & Exhibition
** |

**Symposium
** |
**Computational Materials Engineering for Nuclear Reactor Applications
** |

**Presentation Title** |
Silicon and Vacancy Diffusion near an Edge Dislocation in Nickel under Irradiation |

**Author(s)** |
Zebo Li, Thomas Garnier, Venkateswara Manga, Maylise Nastar, Pascal Bellon, Robert Averback, |

**On-Site Speaker (Planned)** |
Zebo Li |

**Abstract Scope** |
Irradiation produces large point defect concentrations in nuclear reactor materials, leading to enhanced creep rates that can limit reactor efficiency and application lifetime. Accurate modeling of dislocation climb and solute segregation under irradiation, which can provide information for the creep rate evolution, requires a quantitative description of point defect diffusion to sinks like dislocations. We apply phase field simulations to study the time evolution of vacancies and silicon solutes near an edge dislocation in nickel for highly saturated vacancy concentrations due to irradiation. The phase-field model uses Onsager transport coefficients computed from first principles data and self-consistent mean field theory to predict point defect diffusion in the dislocation strain field. We find that large vacancy concentrations enhance Si diffusion and segregation to the dislocation core. We also examine the effects of point defect concentrations and stress on the dislocation climb velocity. |

**Proceedings Inclusion?** |
Planned: A print-only volume |