| About this Abstract |
| Meeting |
2020 TMS Annual Meeting & Exhibition
|
| Symposium
|
Computational Thermodynamics and Kinetics
|
| Presentation Title |
O-10: First-principles Study of Substitutional Solute Diffusion along a Screw Dislocation in fcc Ni |
| Author(s) |
Luke Wirth, Amir A. Farajian, Christopher Woodward |
| On-Site Speaker (Planned) |
Luke Wirth |
| Abstract Scope |
Mass transport through high-diffusivity pathways along dislocation cores is commonly a rate-limiting process for climb and creep mechanisms in fcc metals. Diffusion of solutes through the γ matrix of Ni-base superalloys can create conditions leading to dissolution of the γ' intermetallic precipitates that lend the materials their characteristic strength. Here, the solutes Co, Cr, Al, Ti, and Mo are considered due to their frequent presence in these superalloys. Calculations are based on nudged elastic band-derived migration energies and a kinetic Monte Carlo diffusion model. The results of how solute type affects diffusion rates in an isolated a/2<1 -1 0> screw dislocation partial core (and how those rates differ from those in fcc regions) provide insight on how atoms of each species may inhibit or expedite creep. This behavior in the purely Ni environment will inform expectations for diffusion in the more complex geometry of the γ matrix. |
| Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |