|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||Advanced Characterization Techniques for Quantifying and Modeling Deformation
||In-TEM Observation on Twinning in Nano-sized BCC Crystal
||Scott Mao, Jiangwei Wang, Christopher R. Weinberger, Ting Zhu
|On-Site Speaker (Planned)
This talk will focus on twinning-dominated deformation in nanoscale body-centered cubic (BCC) tungsten. Twinning is a fundamental deformation mode that competes against dislocation slip in crystalline solids. In metallic nanostructures, the higher stresses required for plastic deformation compared to those needed in their bulk counterparts are thought to favor twinning over dislocation slip. Deformation twinning has been well documented in face-centered cubic (FCC) nanoscale crystals, but remains unexplored in BCC nanoscale crystals. Here, by using in situ high-resolution transmission electron microscopy and atomistic simulations, we show that twinning is the dominant deformation mechanism in nanoscale bi-crystals of BCC tungsten. We find that the competition between twinning and dislocation slip can be mediated by loading orientation, which is attributed to the competing nucleation mechanism of defects in nanoscale BCC bi-crystals. Our work provides direct observations of deformation twinning as well as new insights into the deformation mechanism in BCC nanostructures.
||Planned: Supplemental Proceedings volume