Onset Mechanism of Strain Rate Induced Flow Stress Up-turn

Journal Article · Sun Jan 01 00:00:00 EST 2012 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.109.135503· OSTI ID:1055160

Fan, Yue ^[1]; Osetskiy, Yury N ^[1]; Yip, Sidney ^[2]; Yildiz-Botterud, Bilge ^[1]

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1. ORNL
2. Massachusetts Institute of Technology (MIT)

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.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 1055160
• Journal Information: Physical Review Letters, Vol. 109, Issue 13; ISSN 0031--9007
• Country of Publication: United States
• Language: English

Related Subjects

dislocations
plasticity
deformation
strain
stress