| About this Abstract |
| Meeting |
2019 TMS Annual Meeting & Exhibition
|
| Symposium
|
Gamma (FCC)/Gamma-Prime (L12) Co-Based Superalloys III
|
| Presentation Title |
Structural Evolution of a Single Crystal Co-base Superalloy during Creep at 1000ºC/137 MPa |
| Author(s) |
Stoichko Antonov, Song Lu, Longfei Li, Qiang Feng |
| On-Site Speaker (Planned) |
Stoichko Antonov |
| Abstract Scope |
The creep behavior of a novel Co-base single-crystal superalloy was studied at specific creep strains through a sequence of interrupted creep tests at 1000ºC/137MPa. The main deformation mechanism for each creep stage was correlated to the γ-γ′ microstructural and dislocation substructural evolutions. In addition, the lattice misfit at each stage was characterized by synchrotron x-ray diffraction and compared to that of a sample aged in the absence of stress. Finally, phase chemistries of the γ and γ’ phases were measured by atom probe tomography and related to the misfit and microstructural evolution. Interestingly, two steady-state creep stages were observed during the creep process, where interfacial dislocations and γ′ raft formation were responsible for the first steady-state creep stage, while topological inversion and stacking fault interactions, e.g., Lomer-Cottrell locks, led to the second steady-state creep stage. Each deformation mechanism will be discussed individually and related to the complex creep behavior. |
| Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |