About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
|
Accelerated Discovery and Insertion of Next Generation Structural Materials
|
| Presentation Title |
On the Effect of Temperature Cycling and Stress on the Formation of σ-Phase in Single Crystal Superalloys |
| Author(s) |
Takuma Saito, David Buerger, Christoph Somsen, Aleksander Kostka, Gunther Eggeler |
| On-Site Speaker (Planned) |
Takuma Saito |
| Abstract Scope |
Superalloy single crystals like CMSX-4 feature a microstructure consisting of a high volume fraction (e.g. 70%) of cuboidal γ’-particles (L12-phase, average cube edge length: 0.3 µm) separated by thin γ-channels (fcc crystal structure, average channel width: 80 nm). It has been reported that the intermetallic σ-phase can form under certain conditions. In the present study we use scanning and transmission electron microscopy to compare the formation of σ-phase under four conditions: (1) Isothermal exposure at 750, 850 and 950°C for 4, 18 and 42 days. (2) Thermal exposure under the same conditions with an additional creep load of 200 MPa. (3) Load free thermal cycling with targeted hold times of 30 minutes at 750 and 950°C (including short heating and cooling periods). (4) Thermal cycling under 200 MPa using the same temperature time profile. The results show how the kinetics of σ-phase formation is affected by these different exposures. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
High-Temperature Materials, Phase Transformations, Environmental Effects |