Exploring the relation between transonic dislocation glide and stacking fault width in FCC metals
arXiv:2409.10705 · doi:10.1088/1361-651X/adb017
Abstract
Theory predicts limiting gliding velocities that dislocations cannot overcome. Computational and recent experiments have shown that these limiting velocities are soft barriers and dislocations can reach transonic speeds in high rate plastic deformation scenarios. In this paper we systematically examine the mobility of edge and screw dislocations in several face centered cubic (FCC) metals (Al, Au, Pt, and Ni) in the extreme large-applied-stress regime using MD simulations. Our results show that edge dislocations are more likely to move at transonic velocities due to their high mobility and lower limiting velocity than screw dislocations. Importantly, among the considered FCC metals, the dislocation core structure determines the dislocation's ability to reach transonic velocities. This is likely due to the variation in stacking fault width (SFW) due to relativistic effects near the limiting velocities.
14 pages, 6 figures; revised version
References in corpus (9)
- Interatomic potentials for atomistic simulations of the Ti-Al system
- Atomistic simulations of dislocation mobility in Al, Ni and Al/Mg alloys
- Velocity dependent dislocation drag from phonon wind and crystal geometry
- First-principles prediction of the stacking fault energy of gold at finite temperature
- Clarifying the definition of 'transonic' screw dislocations
- Limiting velocities and transonic dislocations in Mg
- Uniformly-moving non-singular dislocations with elliptical core shape in anisotropic media
- Shock-driven nucleation and self-organization of dislocations in the dynamical Peierls model
- Comparing theoretical predictions of radiation-free velocities of edge dislocations to molecular dynamics simulations