Dislocation dynamics simulations with climb: kinetics of dislocation loop coarsening controlled by bulk diffusion

TL;DR

This paper develops and implements dislocation climb mobilities in simulations to study vacancy loop coarsening in metals, revealing that loop glide accelerates coarsening through coalescence.

Contribution

It introduces a new dislocation dynamics simulation approach incorporating climb mobility and compares it with a coarsening model, highlighting the impact of loop glide.

Findings

Climb mobilities derived from vacancy diffusion are effective in simulations.

Loop glide significantly speeds up coarsening kinetics.

Coalescence of loops is a key mechanism when glide is allowed.

Abstract

Dislocation climb mobilities, assuming vacancy bulk diffusion, are derived and implemented in dislocation dynamics simulations to study the coarsening of vacancy prismatic loops in fcc metals. When loops cannot glide, the comparison of the simulations with a coarsening model based on the line tension approximation shows a good agreement. Dislocation dynamics simulations with both glide and climb are then performed. Allowing for glide of the loops along their prismatic cylinders leads to faster coarsening kinetics, as direct coalescence of the loops is now possible.