About this Abstract |
Meeting |
2021 TMS Annual Meeting & Exhibition
|
Symposium
|
Materials for High Temperature Applications: Next Generation Superalloys and Beyond
|
Presentation Title |
Quantifying Deformation Processes Resulting in Local Phase Transformation Strengthening |
Author(s) |
Ashton J. Egan, Veronika Mazanova, Timothy Smith, Timothy Gabb, Timothy Hanlon, Michael Mills |
On-Site Speaker (Planned) |
Ashton J. Egan |
Abstract Scope |
Despite improved understanding of factors controlling high temperature strength, there are still questions concerning the intermediate creep regime dominated by planar defects and microtwinning. A hypothesis is that these deformation mechanisms, and therefore strain rates, are controlled by local segregation events surrounding the leading partial dislocations. Of particular interest are alloys exhibiting Local Phase Transformation (LPT) strengthening at planar defects. In this work, [001] and [110] oriented single crystal analogues of commercially available ME501 and newly developed NASA Alloy were studied to extract fundamental parameters (e.g. activation energies and creep exponents) relating to SESF/microtwin and SISF/ribbon deformation modes while remaining unaffected by grain boundary effects. Scanning Transmission Electron Microscopy was used to study local atomic structure and segregation profiles relating to these processes. As the alloys are similar except content of χ formers, this quantification reflected the extent of LPT strengthening. Interrupted testing also allowed for examination of deformation/microstructural evolution. |
Proceedings Inclusion? |
Planned: |