About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
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Microstructure-Sensitive Modeling Across Length Scales: An MPMD/SMD Symposium in Honor of David L. McDowell
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| Presentation Title |
Strengthening in Superalloys Using Local Phase Transformations at Defects |
| Author(s) |
Michael J. Mills, Andreas Bezold, Ashton Egan, Longsheng Feng, Maryam Ghazisaeidi, Steffen Neumeier, Yunzhi Wang |
| On-Site Speaker (Planned) |
Michael J. Mills |
| Abstract Scope |
Enhancing the efficiency and reducing the carbon emissions of turbomachinery necessitates increasing the operating temperature of polycrystalline superalloys used in turbine disks. In the critical temperature range of 600–800 °C, unconventional deformation mechanisms, including microtwinning and stacking fault shearing of γ′ precipitates, dominant creep processes. These findings are supported by atomic-scale chemical and structural analyses using electron microscopy characterization methods, as well as density functional theory calculations. Notably, these deformation modes are strongly influenced by local phase transformations (LPTs) at the faults, which can either enhance or degrade creep resistance depending on whether ordered or disordered phases form. These atomic-level insights provide a promising pathway for improving the high-temperature performance of these essential materials. Leveraging thermodynamic databases, a predictive framework has been developed to identify alloy compositions that promote LPT-induced strengthening while avoiding LPT-induced softening. This framework has been validated through preliminary alloy production and mechanical testing. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Mechanical Properties, Characterization, Phase Transformations |