About this Abstract |
Meeting |
2024 TMS Annual Meeting & Exhibition
|
Symposium
|
Computational Thermodynamics and Kinetics
|
Presentation Title |
Vacancy-mediated Transport of Solute Atoms in fcc Nickel under Diffusional Creep: A Density Functional Theory Study |
Author(s) |
Shehab Shousha, Boopathy Kombaiah, Sourabh Kadambi |
On-Site Speaker (Planned) |
Shehab Shousha |
Abstract Scope |
Nickel-based alloys are known for their excellent corrosion resistance and high-temperature strength. However, at high temperatures, polycrystals experience grain boundary-stress-driven vacancy diffusion leading to diffusion creep. Understanding the fundamentals of defect migration and interactions is essential to predict such diffusion creep behavior. In this talk, we explore the Nabarro-Herring creep and the associated solute segregation that is likely to result from the different diffusivities of the solute and solvent elements. Density functional theory calculations are performed to determine the formation, migration and binding energies of the solute and vacancy defects in stress-free and stressed states. The dilute-limit transport coefficients are then calculated using the self-consistent mean field theory as implemented in the KineCluE code. Predictions of diffusion creep strain rates and solute segregation are then presented for various solutes, stresses, and temperatures. This work opens research avenues for exploration of diffusion creep via characterization of elemental segregation to grain boundaries. |
Proceedings Inclusion? |
Planned: |
Keywords |
Computational Materials Science & Engineering, Copper / Nickel / Cobalt, Modeling and Simulation |