|About this Abstract
||2016 TMS Annual Meeting & Exhibition
||Advanced Characterization Techniques for Quantifying and Modeling Deformation
||Quantitative Analysis of Local Stress Concentration in Nanotwinned Metal during Plastic Deformation
||Kui Du, Ning Lu, Lei Lu, Hengqiang Ye
|On-Site Speaker (Planned)
Metals with nanometer-scaled twins demonstrate high strength and good ductility. These are related to interactions between dislocations and coherent twin boundaries. Since the twin boundaries are strong barriers for dislocation glide, the strength of nanotwinned metals presumably increases with decreasing twin lamella spacing. However, when the twin lamella spacing becomes less than a critical thickness, a softening behavior takes place. In this work, from the quantitative analysis of local stress, the statistics of dislocation activities by in situ TEM and the result from mechanical testing, a direct relationship can be established between dislocation activities and the strength of nanotwinned metals. The stress states measured from high-resolution TEM reveal that local stress concentrations vary significantly with the twin lamella spacing, thus a critical twin lamella spacing is determined for the transition from strengthening to softening of nanotwinned copper. The result agrees quantitatively with the experimentally measured critical spacing.
||Planned: EPD Congress Volume