About this Abstract |
| Meeting |
MS&T24: Materials Science & Technology
|
| Symposium
|
Tackling Metallic Structural Materials Challenges for Advanced Nuclear Reactors
|
| Presentation Title |
Density Functional Theory Study of Helium diffusion in Ni-M Alloys (M= Cr, Mo) |
| Author(s) |
Ximeng Wang, Yachun Wang, Yongfeng Zhang |
| On-Site Speaker (Planned) |
Ximeng Wang |
| Abstract Scope |
High temperature He embrittlement (HTHE) is a key structural performance issue upon fast neutron irradiation. This may occur with very low He concentration due to bubble formation along grain boundaries. Studying He diffusion in the alloys of interest is essential to understand the kinetics for bubble formation. Taking face centered cubic (FCC) Ni as the host metal, Cr and Mo atom are introduced to represent Ni-Cr and Ni-Mo alloys. Applying density functional theory (DFT), nudged elastic band (NEB) and ab-initio molecular dynamics (AIMD) calculations are used to study the He diffusivity in pure Ni, Ni-Cr and Ni-Mo. We found that He is attracted by Cr and repelled by Mo in fcc Ni. Accordingly, Cr retards and Mo accelerates He diffusion compared to the case in pure Ni. |