| About this Abstract |
| Meeting |
2020 TMS Annual Meeting & Exhibition
|
| Symposium
|
Advancing Current and State-of-the-Art Application of Ni- and Co-based Superalloys
|
| Presentation Title |
First-principles Study of Displacive-diffusive Phase Transformations during High Temperature Creep: from Ni- to Co-based Superalloys |
| Author(s) |
Dongsheng Wen, Sae Matsunaga, Michael S. Titus |
| On-Site Speaker (Planned) |
Dongsheng Wen |
| Abstract Scope |
Displacive-diffusive phase transformations that involve complex shearing, reordering, and diffusion mechanisms in the L12-γ’ phase during high temperature creep have recently been observed in Ni-, NiCo-, and Co-based superalloys. These phase transformations have subsequently been correlated with the high temperature mechanical properties of these alloys. While the driving forces in some alloys have been identified and limited experimental evidence for such phase transformations has been gathered, a wholistic understanding of these complex processes has yet to emerge. To better understand these processes, we have calculated the driving force for solute segregation to superlattice intrinsic stacking faults as a function of Co content utilizing first-principles density functional theory calculations. The driving force for solute segregation, which appears to be a precursor for phase transformations, increases as a function of Co content. These results and implications for future alloy design will be discussed. |
| Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |