| About this Abstract |
| Meeting |
2020 TMS Annual Meeting & Exhibition
|
| Symposium
|
Mechanical Behavior at the Nanoscale V
|
| Presentation Title |
Dislocation Nucleation-mediated Plasticity of FCC Defect-scarce Nanowires |
| Author(s) |
Jungho Shin, Zhuocheng Xie, Gunther Richter, Erik Bitzek, Daniel S. Gianola |
| On-Site Speaker (Planned) |
Jungho Shin |
| Abstract Scope |
Defect-scarce nanowires often feature superior mechanical properties by reaching their theoretical strength limit. Revealing the limiting-step for strength determinations and their subsequent plasticity is not fully understood, partly due to challenges in experimentally observing the dynamics. Here, we report quantitative in situ tensile tests on nucleation dominant dislocation-mediated plasticity of <110> Pd and Au nanowires (d~100 nm). Experimentally extracted activation parameters suggest surface diffusional activity is a key to the incipient plasticity at finite temperature, and applying ultra-thin coatings can tailor the nucleation stress as well as the plasticity behavior. Presence of axial planar boundaries strengthens the nanowire by blocking the nucleated dislocations, which is corroborated by an MD simulation. We demonstrate importance of frame stiffness in nanotensile tests, which opens an avenue to studies of plastic deformation associated with complex dislocation dynamics following nucleation of dislocations into pristine nanowires. |
| Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |