| About this Abstract |
| Meeting |
2020 TMS Annual Meeting & Exhibition
|
| Symposium
|
Mechanical Behavior at the Nanoscale V
|
| Presentation Title |
Dislocation-twinning Competitions in Body-centered Cubic Metallic Nanowires |
| Author(s) |
Chaoming Yang, Liang Qi |
| On-Site Speaker (Planned) |
Liang Qi |
| Abstract Scope |
Without preexisting deformation defects, a nanowire (NW) can reach near-ideal tensile strength and deform by nucleating defects, such as dislocations and deformation twinning, from its free surfaces. In particular for the body-centered cubic (BCC) NWs of refractory metals growing along <100>, deformation twinning is commonly observed and is responsible for the pseudoplasticity under <100> tension. Recently we build a modified embedded-atom method (MEAM) potential of Niobium (Nb) that can reproduce its ideal tensile strength behavior. Based on MEAM potentials of Nb and Molybdenum (Mo), molecular dynamics simulations show different deformation behaviors for NWs under <001> tension. Mo NWs always have the typical deformation twinning, but there are interesting competitive phenomena between dislocations and deformation twinning in Nb NWs. These competitions depend on temperatures and NW geometry. Analyses of the effects of interatomic bonding characteristics to these dislocation-twinning competitions deepen our understanding of deformation mechanisms at the nanoscale. |
| Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |