Investigation of partial dislocations fluctuations yields dislocation core parameters

Pierre-Antoine Geslin (1) , David Rodney (2)

1 MATEIS - Matériaux, ingénierie et science [Villeurbanne]
2 iLM - MMCI - iLM - Modélisation de la matière condensée et des interfaces

In this work, we investigate the thermal uctuations of dissociated dislocations in face-centered cubic metals. We rst derive an analytical expression of the energy of perturbed interacting partial dislocations. Combining this expression with the equipartition theorem yields a prediction for the thermal uctuations of interacting partials. Comparing this prediction with atomistic calculations in nickel allows to extract the core energy of the partials at nite temperature and as function of their orientation. We also show how to use these values to parameterize the energetics of perfect dislocations and clarify the scope of validity of representing dissociated dislocations as perfect dislocation lines, an approximation customarily made in dislocation dynamics approaches.

Mots clés: dislocation; core parameters; thermal uctuations

Domaines: Mécanique des matériaux [physics.class-ph]; Matériaux; Matière Condensée [cond-mat]

Pierre-Antoine Geslin, David Rodney. Investigation of partial dislocations fluctuations yields dislocation core parameters. Modelling and Simulation in Materials Science and Engineering, 2020, 28 (5), pp.055006. ⟨10.1088/1361-651X/ab8a96⟩. ⟨hal-02972044⟩