Comparing theoretical predictions of radiation-free velocities of edge dislocations to molecular dynamics simulations

Abstract

Transonic defect motion is of interest for high strain-rate plastic deformation as well as for crack propagation. Ever since Eshelby's 1949 prediction in the isotropic limit of a 'radiation-free' transonic velocity $v_{\text{RF}}=\sqrt{2}{c}_{\text{T}}$, where shock waves are absent, there has been speculation about the significance of radiation-free velocities for defect mobility. Here, we argue that they do not play any significant role in dislocation dynamics in metals, based on comparing theoretical predictions of radiation-free velocities for transonic edge dislocations with molecular dynamics simulations for two face-centered cubic (FCC) metals: Cu, which has no radiation-free states, and Ag, which does.

16 pages, 7 figures, 2 tables; v2+v3 expanded revision, v4 title changed

References in corpus (3)

• Analytic model of the remobilization of pinned glide dislocations: including dislocation drag from phonon wind
• Clarifying the definition of 'transonic' screw dislocations
• Limiting velocities and transonic dislocations in Mg

Cited by in corpus (2)

• Exploring the relation between transonic dislocation glide and stacking fault width in FCC metals
• PyDislocDyn: A Python code for calculating dislocation drag and other crystal properties