About this Abstract |
| Meeting |
2027 TMS Annual Meeting & Exhibition
|
| Symposium
|
Magnesium Technology 2027
|
| Presentation Title |
Differential gliding behavior of edge and screw pyramidal dislocations in magnesium |
| Author(s) |
Fei Liu, Yaofeng Li, Boyu Liu, Zhiwei Shan, Bin Li |
| On-Site Speaker (Planned) |
Bin Li |
| Abstract Scope |
Pyramidal dislocations in hexagonal close-packed metals play a crucial role in accommodating strains along the [0001] direction because both basal and prismatic dislocations are unable to. In post-mortem transmission electron microscopy (TEM) studies, the diffraction contrast of pyramidal dislocations present a very abnormal morphology – nearly perfect straight lines always parallel to the trace of the basal plane. Short segments connecting these straight lines are sometimes observed and they are oftentimes interpreted as a result of cross-slip. In this work, we perform in-situ TEM observations of pyramidal dislocation slip in Mg single crystals that are compressed nearly along the [0001] direction. The results reveal that edge pyramidal dislocations present a stick-slip-type motion mode, whereas screw pyramidal dislocations glide much smoother with a critical stress about two orders of magnitude lower than that of edge pyramidal dislocations. Atomistic simulations are also conducted to better understand the underlying physics. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Magnesium, Characterization, Computational Materials Science & Engineering |