| About this Abstract |
| Meeting |
2023 TMS Annual Meeting & Exhibition
|
| Symposium
|
Refractory Metals 2023
|
| Presentation Title |
Dislocation Emission from Crack Tips in Cr Studied by In-situ TEM |
| Author(s) |
Daniel Kiener, Michael Burtscher, Inas Issa, Klemens Schmuck, Christoph Gammer, Stefan Sandfeld |
| On-Site Speaker (Planned) |
Daniel Kiener |
| Abstract Scope |
Despite their many favorable properties for high-performance applications in harsh environments, refractory metals commonly suffer from their inherent brittleness. Furthermore, when attempting to improve material strength by refining the microstructure into the ultra-fine grained regime, the failure mode commonly changes from transcrystalline to intercrystalline fracture. To circumvent this, a key factor is to reinforce weak grain boundaries by increasing grain boundary cohesion, e.g. using doping elements. In this work, crack tip processes in single crystal Cr and ultra-fine grained Cr, with and without C doping to strengthen grain boundaries, were studied using in-situ TEM nanomechanical testing. By deliberately placing the sharp crack tip in the grain interior or at the grain boundary, we examine differences with respect to local stress intensities required to nucleate dislocations from the crack tip in the grain compared to clean or doped grain boundaries and relate this to brittle cleavage of the interfaces. |
| Proceedings Inclusion? |
Undecided |
| Keywords |
Mechanical Properties, High-Temperature Materials, |