Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA.
Phys Rev Lett. 2018 Mar 23;120(12):125504. doi: 10.1103/PhysRevLett.120.125504.
The interaction between an edge dislocation and a sessile vacancy cluster in bcc Fe is investigated over a wide range of strain rates from 10^{8} down to 10^{3} s^{-1}, which is enabled by employing an energy landscape-based atomistic modeling algorithm. It is observed that, at low strain rates regime less than 10^{5} s^{-1}, such interaction leads to a surprising negative strain rate sensitivity behavior because of the different intermediate microstructures emerged under the complex interplays between thermal activation and applied strain rate. Implications of our findings regarding the previously established global diffusion model are also discussed.
本文采用基于能量景观的原子建模算法，研究了 bcc Fe 中刃型位错与定域空位团簇在很宽应变率范围内（从 10^{8} 到 10^{3} s^{-1}）的相互作用。研究发现，在应变率较低的区域（小于 10^{5} s^{-1}），由于热激活和外加应变率之间的复杂相互作用导致不同的中间微观结构的出现，这种相互作用导致了令人惊讶的负应变率敏感性行为。本文还讨论了我们的发现对先前建立的全局扩散模型的影响。
