| About this Abstract |
| Meeting |
2022 TMS Annual Meeting & Exhibition
|
| Symposium
|
Fatigue in Materials: Fundamentals, Multiscale Characterizations and Computational Modeling
|
| Presentation Title |
Prediction of Critical Stress by Anisotropic Calculation of Dislocation Core-width |
| Author(s) |
Orcun Koray Celebi, Ahmed Sameer Khan Mohammed, Jessica Anne Krogstad, Huseyin Sehitoglu |
| On-Site Speaker (Planned) |
Orcun Koray Celebi |
| Abstract Scope |
Fatigue threshold is predominantly dictated by the Critical Resolved Shear Stress (CRSS) for dislocation glide at the front of short cracks. Existing approaches cannot truly predict the CRSS (consequently fatigue resistance) due to inherent empiricism in handling the core of the dislocation. We propose an ab-initio predictive model for the CRSS by determining the dislocation core-width which is determined by minimization of total energy comprising elastic and misfit energies. The elastic strain-energy is calculated by numerical integration of anisotropic strain-fields derived from the Eshelby-Stroh formalism and the misfit energies are determined from the fault energies of the slip system. The predictive efficacy of the approach is demonstrated by estimating CRSS for several metals and alloys showing good agreement with the available experimental data. The model establishes the influence of character of the dislocation for the first time, along with the relative importance of the unstable and stable stacking fault energies. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Computational Materials Science & Engineering, High-Entropy Alloys, |