Mild-to-wild plastic transition is governed by athermal screw dislocation slip in bcc Nb.

ABSTRACT: Plastic deformation in crystals is mediated by the motion of line defects known as dislocations. For decades, dislocation activity has been treated as a homogeneous, smooth continuous process. However, it is now recognized that plasticity can be determined by long-range correlated and intermittent collective dislocation processes, known as avalanches. Here we demonstrate in body-centered cubic Nb how the long-range and scale-free dynamics at room temperature are progressively quenched out with decreasing temperature, eventually revealing intermittency with a characteristic length scale that approaches the Burgers vector itself. Plasticity is shown to be bimodal across the studied temperature regime, with conventional thermally-activated smooth plastic flow ('mild') coexisting with sporadic

SUBMITTER: Rizzardi Q 

PROVIDER: S-EPMC8866410 | biostudies-literature | 2022 Feb

REPOSITORIES: biostudies-literature