Atomistic Insights into Disclocation Dynamics in Metal Forming
Francesca Tavazza, Anne M. Chaka, Lyle E. Levine
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.
To Be Determined
ab initio, density funcitonal theory, dislocations, EAM, embedded atom, vacancy
, Chaka, A.
and Levine, L.
Atomistic Insights into Disclocation Dynamics in Metal Forming, To Be Determined
(Accessed June 4, 2023)