|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||Mechanical Behavior at the Nanoscale IV
||Molecular Dynamics Study on Temperature-dependent Screw Dislocation Behavior in Body-centered Cubic Metal Nanopillars
||Gyuho Song, Seok-Woo Lee
|On-Site Speaker (Planned)
Recent studies in nanopillars plasticity suggested that dislocation cross-slip at the free surface plays an important role in dislocation multiplication in a small volume. Particularly for body-centered cubic (bcc) structure, the relative difference in mobility between screw and edge dislocation is critical to induce the surface-controlled dislocation multiplication. The dislocation mobility of bcc metal is strongly dependent of temperature and intrinsic lattice resistance and so should the surface-controlled multiplication behavior.
In this molecular dynamics study, we chose bcc niobium and molybdenum nanopillars and investigated how a single pure screw dislocation evolves through surface-controlled multiplication at different temperatures and sizes. Our results revealed that the critical stress of multiplication conservatively decreases with temperature and nanopillars size. We will discuss our computational results in terms of absolute/relative mobility between screw and edge dislocations. Our study will bridge experiment and computation on dislocation multiplication behavior in bcc metal nanopillars.
||Planned: Supplemental Proceedings volume