| About this Abstract |
| Meeting |
2020 TMS Annual Meeting & Exhibition
|
| Symposium
|
Metastable Phases and Phase Equilibria: Towards Designing the Next Generation of Alloys
|
| Presentation Title |
Deformation Mechanisms in Metastable Fcc Alloys |
| Author(s) |
Mulaine Shih, Maryam Ghazisaeidi |
| On-Site Speaker (Planned) |
Mulaine Shih |
| Abstract Scope |
We study the concept of average versus "local" stacking fault energy (SFE), and their fundamental role in dislocation behavior in fcc alloys. Recent studies in high entropy alloys (HEAs) have revealed the existence of composition-dependent metastable phases. Transitioning from fcc to hcp stable phases in fcc alloys correspond to a change from positive to negative average values for the SFE. The goal of this work is to understand the different deformation mechanisms at the atomic-scale as a function of composition, while the average SFE value changes sign. We perform atomistic simulations on random NiCo alloys as a model system to investigate the dislocation behavior in positive/negative SFE materials. Using molecular dynamics simulations, we show how deformation mechanisms vary as a function of concentration, temperature and applied stress. Our results provide a fundamental understanding of how changes in composition can tune deformation mechanisms, and consequently mechanical behavior in fcc solid solutions. |
| Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |