| About this Abstract |
| Meeting |
2025 TMS Annual Meeting & Exhibition
|
| Symposium
|
Phase Transformations and Microstructural Evolution
|
| Presentation Title |
Novel Co-based Superalloys Strengthened via Local Phase Transformation at Microtwins and Stacking Faults |
| Author(s) |
Ashton J. Egan, Andreas Bezold, Longsheng Feng, Christopher Zenk, Yunzhi Wang, Michael Mills, Steffen Neumeier, Erdmann Spiecker, Mathias Göken |
| On-Site Speaker (Planned) |
Ashton J. Egan |
| Abstract Scope |
Local Phase Transformation (LPT) at planar defects has proved to prevent rapid damage accumulation in the intermediate temperature creep regime of both Ni- and Co-based superalloys (~700-850°C) used for aerospace engines by halting further shearing partial dislocations. LPT design has largely focused on η-LPT at superlattice extrinsic stacking faults (SESFs), utilizing a computational framework employing high throughput thermodynamic calculations via initial composition input and optimized alloy output. Here, this has been applied to Co-based superalloys, for which it had not been attempted; both η-SESF and χ-SISF/χ-microtwin LPT were optimized. To study fundamental deformation and effectiveness of LPT under specific loading conditions, single crystals were cast and enabled deformation response to be mapped as a function of orientation, namely [001] (enabling SESF/microtwinning) and [011] (enabling SISF and SF ribbons) crystallographic directions. Atomic resolution HR-STEM observations of deformation substructure informed design of an optimal creep-resistant polycrystalline alloy and refined computational framework. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
High-Temperature Materials, Phase Transformations, Mechanical Properties |