| About this Abstract |
| Meeting |
2021 TMS Annual Meeting & Exhibition
|
| Symposium
|
100 Years and Still Cracking: A Griffith Fracture Symposium
|
| Presentation Title |
Dislocations Processes in Fracture and Toughening Mechanisms of UFG bcc Metals at Room Temperature |
| Author(s) |
Inas Issa, Anton Hohenwarter, Jakub Zálešák, Daniel Kiener |
| On-Site Speaker (Planned) |
Inas Issa |
| Abstract Scope |
We present in situ TEM fracture experiments on ultrafine-grained chromium (UFG, Cr) that reveal explicitly the occurrence of dislocation emission processes before intercrystalline fracture in UFG bcc metals at RT. These processes and related crack tip blunting serve as toughening mechanisms. Moreover, different in situ tests, with notches inside the grains or along grain boundaries (GBs) explicitly shows the importance of strengthening GBs as promising strategy in promoting further ductility and toughening in UFG bcc metals.
Impurities such as Carbon or Boron acts as adhesion improving impurities that can modify the atomistic GBs configuration in front of the notch. We present a comparative mechanical study showing an improved ductility in UFG Cr- Carbon alloyed compared to pure UFG Cr. Electron Energy Loss Spectroscopy (EELS), TEM technique, is used to identify the Carbon segregation at GBs. This allows the understanding of how local segregation affects GBs cohesion and fracture toughness. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Mechanical Properties, |