About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
|
Advances in the State-of-the-Art of High Temperature Alloys
|
| Presentation Title |
In-Situ Observation of Recrystallization in Pre-Strained Ni-Based Single Crystal Superalloy Simulating Rejuvenation Heat Treatment |
| Author(s) |
Satoshi Utada, Anh Hoang Pham, Mitsuaki Takemoto, Yuanbo T Tang, Graham McCartney, Roger C. Reed |
| On-Site Speaker (Planned) |
Satoshi Utada |
| Abstract Scope |
To address cost and supply issues of scarce and critical elements in Ni-based single crystal superalloys for turbine blades, rejuvenation heat treatments are being explored to repair and extend component life. This study investigates the boundary conditions for recrystallization in pre-strained STAL15 Ni-based superalloy using high temperature in-situ confocal laser scanning microscopy (HT-CLSM) and ex-situ electron microscopy techniques. Pre-strain was introduced via room temperature site specific indentations and high-temperature uniaxial tension test at 950 °C. In-situ HT-CLSM enabled accurate measurement of onset temperature of recrystallization and grain evolution processes. Results from indentations showed that local recrystallization temperatures vary between dendrite core and interdendritic regions, correlating with the local γ′ solvus temperature. Higher local strain increased the dislocation density within the γ′ precipitates, promoting recrystallization nucleation above the solvus temperature. In conclusion, excessive local strain accumulation is the cause of undesirable recrystallization during the rejuvenation, potentially impacting component integrity. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Characterization, Sustainability, Process Technology |