| About this Abstract |
| Meeting |
2025 TMS Annual Meeting & Exhibition
|
| Symposium
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Atomistic Simulations Linked to Experiments to Understand Mechanical Behavior: A MPMD Symposium in Honor of Professor Diana Farkas
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| Presentation Title |
Local Phase Transformation Strengthening in Ni-Base Superalloys |
| Author(s) |
Michael J. Mills, Ashton Egan, Andreas Bezold, Longsheng Feng, Timothy Smith, Maryam Ghazisaeidi, Yunzhi Wang |
| On-Site Speaker (Planned) |
Michael J. Mills |
| Abstract Scope |
Improving engine efficiency and reducing carbon emissions of turbomachinery requires increasing the operating temperature of polycrystalline superalloy alloys used in turbine disks. In the critical temperature range of 600-800°C, unusual deformation mechanisms including microtwinning and stacking fault shearing through the strengthening γ’ precipitates have been identified as the important operative creep mechanisms based on atomic-scale chemical and structural analyses, and supported by DFT calculations. Furthermore, these important deformation modes can be strongly influenced by local phase transformations (LPT) at the faults, which can either soften or strengthen the creep behavior, depending on whether disordered or ordered phases form at the faults. These atomic-scale insights offer a new pathway for improving the high temperature properties of these critical materials. Using thermodynamic databases, a framework for predicting alloy compositions that enhance LPT strengthening and avoid LPT softening has been developed and validated with preliminary mechanical testing. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Characterization, Mechanical Properties, Phase Transformations |