About this Abstract |
| Meeting |
2022 TMS Annual Meeting & Exhibition
|
| Symposium
|
Ultrafine-grained and Heterostructured Materials (UFGH XII)
|
| Presentation Title |
Implications of Fatigue-crack Healing in Nanocrystalline Metals |
| Author(s) |
Brad L. Boyce, Christopher Barr, Ta Duong, Daniel Bufford, Abhilash Molkeri, Nathan Heckman, David Adams, Ankit Srivastava, Khalid Hattar, Michael Demkowicz |
| On-Site Speaker (Planned) |
Brad L. Boyce |
| Abstract Scope |
In-situ TEM high-cycle fatigue experiments on electron transparent thin films of nanocrystalline Ni and Cu have revealed not only microstructural-sensitive crack propagation, but also unexpected microstructural-scale crack healing. Based on the experimental observations, atomistic modeling, and continuum-scale microstructural modeling, the mechanism appears to be crack flank cold welding facilitated by local compressive microstructural stresses and/or grain boundary migration. While these observations are specific to pure nanocrystalline metal thin films under a high-vacuum environment, there are potentially much broader ramifications. The existing observations can be used to help rationalize suppressed fatigue crack propagation rates in vacuum, subsurface, or under contact-inducing mixed-mode stresses; and even the precipitous decline in propagation rates near the fatigue threshold. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Mechanical Properties, Thin Films and Interfaces, Nanotechnology |