| About this Abstract |
| Meeting |
2016 TMS Annual Meeting & Exhibition
|
| Symposium
|
2016 Technical Division Student Poster Competition
|
| Presentation Title |
SPG-57: Strength Prediction in NiCo Alloys - The Role of Composition and Nanotwins |
| Author(s) |
Piyas Chowdhury, Huseyin Sehitoglu, Hans Maier, Richard Rateick |
| On-Site Speaker (Planned) |
Piyas Chowdhury |
| Abstract Scope |
Experimentally, tensile constitutive behaviors of nano-twinned Ni-Co alloys demonstrate the existence of a critical composition to achieve maximum strength. First, from ab initio calculations, we discover that the alloy gamma surface follows the same trend as a result of a competition between the solid solution hardening and the Suzuki segregation. Secondly, various slip-twin boundary interactions mechanisms are found to alter the alloy γ surface via molecular dynamics simulations. We compute the respective unstable stacking fault energies, which are then converted into frictional stresses within a Peierls-Nabarro modeling framework. Then, critical resolved shear stresses (CRSS) are predicted for different Ni-Co alloys, utilizing the first principle and the molecular dynamics results. In conclusion, the apparently puzzling trends in the Ni-Co macroscopic strengths are rationalized by considering the combined effects of: (a) the twin influenced slip activities at the mesoscale and (b) the alloying induced fault energetics at the quantum scale. |
| Proceedings Inclusion? |
Definite: None Selected |