Atomistic Insights into Disclocation Dynamics in Metal Forming

Published

October 12, 2021

Author(s)

Francesca Tavazza, Anne M. Chaka, Lyle E. Levine

Abstract

Almost all of the mechanical behavior changes that occur during plastic deformation result from the evolution of dislocation structures. Statistical models, like strain percolation theory, have been developed to understand the transport of dislocations through these structures, but the incorporation of real physical featues, such as vacancy concentration, requires investigation at the atomistic level. In this work, we introduce a new, hybrid ab initio-classical simulation methodology that allows us to conduct large-scale atomistic simulations with a simple classical potential (embedded atom method (EAM), for instance) while simultaneously using a more accurate ab initio approach for critical embedded regions. The initial atomic positions and boundary conditions for the EAM simulations come from elastic displacement fields provided by elasticity theory. Iteratively, the critical region is relaxed using density functional theory and the much large cell in which this is embedded is relaxed using a Monte-Carlo algorithm with EAM potentials. Applications of this method to the evaluation of vacancy formation energies at different distances from a dislocation core are discussed.

Citation

To Be Determined

Pub Type

Journals

Keywords

ab initio, density funcitonal theory, dislocations, EAM, embedded atom, vacancy

Citation

Tavazza, F. , Chaka, A. and Levine, L. (2021), Atomistic Insights into Disclocation Dynamics in Metal Forming, To Be Determined (Accessed April 18, 2024)