About this Abstract |
Meeting |
2022 TMS Annual Meeting & Exhibition
|
Symposium
|
Dynamic Behavior of Materials IX
|
Presentation Title |
Twinning-assisted Dynamic Recrystallization: A New Mechanism Revealed by Single Microparticle Supersonic Impact |
Author(s) |
Ahmed Alade Tiamiyu, Edward L Pang, Christopher A Schuh |
On-Site Speaker (Planned) |
Ahmed Alade Tiamiyu |
Abstract Scope |
Grain refinement by dynamic recrystallization during deformation of FCC metals is usually explained by dislocation-mediated mechanisms. However, dynamic recrystallization remains mysterious in the high strain rate (low temperature) regime where twinning is a dominant plastic deformation mechanism. In this work, we employ single copper microparticle impact experiments at varying velocities to systematically shift the deformation conditions into this regime. Post mortem impacts have been characterized using transmission electron microscopy and dictionary indexing electron backscatter diffraction, which reveal a twin-assisted dynamic recrystallization mechanism. In the twin-mediated mechanism, nanotwins first form and are then partitioned by dislocation activity to form nano-grains smaller than what conventional dislocation-mediated recrystallization mechanisms produce. This finding fills in the gaps at high strains and strain rates in a deformation mechanism map for FCC copper. |
Proceedings Inclusion? |
Planned: |