Publication Type
Journal
Journal Name
Physical Review Letters
Publication Date
Page Number
135503
Volume
109
Issue
13
Abstract
The strain-rate response of flow stress in a plastically deforming crystal is formulated through a stresssensitive dislocation mobility model that can be evaluated by atomistic simulation. For the flow stress of a model crystal of bcc Fe containing a 1/2 <111> screw dislocation, this approach describes naturally a non-Arrhenius upturn at high strain rate, an experimentally established transitional behavior for which the underlying mechanism has not been clarified. Implications of our findings regarding the previous explanations of strain-rate effects on flow stress are discussed.
