| About this Abstract |
| Meeting |
2010 TMS Annual Meeting & Exhibition
|
| Symposium
|
General Abstracts: Structural Materials Division
|
| Presentation Title |
The Role of Non-Planar Deformation in Cyclic Softening Following Low Cycle Fatigue of a Ni-Based Superalloy |
| Author(s) |
Patrick J Phillips, Raymond R Unocic, Libor Kovarik, Dan Wei, David Mourer, Michael J Mills |
| On-Site Speaker (Planned) |
Patrick J Phillips |
| Abstract Scope |
Cyclic softening is a common material response during low cycle fatigue (LCF) over a wide range of testing temperatures. The polycrystalline Ni-based superalloy explored in this study exhibits this softening behavior, but only at elevated temperatures. This tendency is likely a result of activating new deformation modes depending on time and temperature. Using transmission electron microscopy characterization methods, the evolution of damage mechanisms was studied on specimens interrupted after a limited number of cycles. Both fine and coarse precipitate microstructures were examined, corresponding to a fast or slow cool, respectively, from the gamma prime solvus temperature. The operative deformation mechanisms are correlated with the precipitate structure, number of cycles, and testing temperature. The observed deformation modes include paired APB shearing, intense dislocation bands on {111} planes, and eventual cross-slipping processes between {111} and {100} planes. A rationale for the observed mechanisms in terms of time-dependent damage processes will be discussed. |
| Proceedings Inclusion? |
Definite: A CD-only volume |