|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Mechanical Behavior of Nanostructured Materials
||Grain Boundaries Shear-migration Coupling and Its Impact on Plastic Deformation in Nanocrystalline Metals
||Marc Legros, Frédéric Mompiou, Nicolas Combe, Ehsan Hosseinian, Olivier Pierron
|On-Site Speaker (Planned)
The absence of dislocations in nanocrystalline metals precludes an easy plastic deformation. A key alternative mechanism is called the shear-migration coupling of grain boundary. This mechanism is able to produce a significant shear under stress, accompanied by grain growth that may further help relaxing the applied mechanical load. This mechanism is however poorly characterized in polycrystals experimentally or theoretically. We have conducted both in-situ TEM experiments, grain orientation mapping and molecular dynamic simulations that shown that shear-migration coupling involves the displacement of linear defects called disconnections that are specific to grain boundaries. As dislocations in the crystal, the properties of these disconnections seem to guide the coupling mechanism of migrating grain boundaries. The same disconnections are also involved in GB sliding and grain rotation.
||Planned: Supplemental Proceedings volume