|About this Abstract
||2016 TMS Annual Meeting & Exhibition
||Ultrafine Grained Materials IX
||Grain-Size Dependent Mechanical Behavior of Nanocrystalline Metals
||Marc Andre Meyers, Eric Hahn, Eduardo Bringa, Yzhe Tang
|On-Site Speaker (Planned)
||Marc Andre Meyers
Grain size has a profound effect on the mechanical response of metals. Molecular dynamics continues to expand its range to grain sizes up to 50 nm, albeit commonly at strain rates generally upwards of 10e6 s-1. The different grain size regimes are dominated by different mechanisms. We focus here in the region d < 100 nm, the nanocrystalline region. An interesting and representative phenomenon at this reduced spatial scale is the inverse Hall-Petch effect observed experimentally and in MD simulations in FCC, BCC, and HCP metals. We compare the results of molecular dynamics simulations with analytical models and mechanisms based on the contributions of Conrad and Narayan and Argon and Yip, who attribute the inverse Hall-Petch relationship to the increased contribution of grain-boundary shear as the grain size is reduced. The occurrence of twinning, more prevalent at the high strain rates enabled b y shock compression, is evaluated.