About this Abstract |
Meeting |
2023 TMS Annual Meeting & Exhibition
|
Symposium
|
Fatigue in Materials: Fundamentals, Multiscale Characterizations and Computational Modeling
|
Presentation Title |
Molecular Dynamics Simulations of the Thermal Evolution of Voids in Cu Bulk and Grain Boundaries |
Author(s) |
Vasileios Fotopoulos, Alexander Shluger, Ricardo Grau-Crespo, Corey S. O'Hern |
On-Site Speaker (Planned) |
Vasileios Fotopoulos |
Abstract Scope |
In this work, we combined Density Functional Theory (DFT) with Bond Order potentials (BOP) Molecular Dynamics (MD) simulations to examine the effect of hydrogen in the properties of the polycrystalline Cu. Our tensile strain MD simulations showed that grain boundaries (GBs) and triple junctions aggregate high stresses which they release via the emission of twin dislocations. Dislocation analysis showed that the presence of H facilitates the formation of Shockley dislocations close to the GBs. Delaunay tessellation analysis showed that H and Cu vacancies complexes in Σ5 GBs withstand temperatures up to 700 K without dissociating, with H having a stabilization effect in the vacancies in GBs during thermal annealing. DFT showed that the presence of H interstitials significantly decreases the formation energies of mono, di-vacancies and tri-vacancies. Thus, H presence in the GBs is expected to increase locally the concentration of vacancies and facilitate the growth of larger vacancy clusters. |
Proceedings Inclusion? |
Planned: |
Keywords |
Modeling and Simulation, Copper / Nickel / Cobalt, Mechanical Properties |