title: Multiscale modeling of dislocation-precipitate interactions in Fe: From molecular dynamics to discrete dislocations.
abstract: The stress-driven motion of dislocations in crystalline solids, and thus the ensuing plastic deformation process, is greatly influenced by the presence or absence of various pointlike defects such as precipitates or solute atoms. These defects act as obstacles for dislocation motion and hence affect the mechanical properties of the material. Here we combine molecular dynamics studies with three-dimensional discrete dislocation dynamics simulations in order to model the interaction between different kinds of precipitates and a 1/2〈111〉{110} edge dislocation in BCC iron. We have implemented immobile spherical precipitates into the ParaDis discrete dislocation dynamics code, with the dislocations interacting with the precipitates via a Gaussian potential, generating a normal force acting on the dislocation segments. The parameters used in the discrete dislocation dynamics simulations for the precipitate potential, the dislocation mobility, shear modulus, and dislocation core energy are obtained from molecular dynamics simulations. We compare the critical stresses needed to unpin the dislocation from the precipitate in molecular dynamics and discrete dislocation dynamics simulations in order to fit the two methods together and discuss the variety of the relevant pinning and depinning mechanisms.
authors: Department of Applied Physics, Aalto University School of Science, P.O. Box 11100, FIN-00076 Aalto, Espoo, Finland.
authors: Arttu
authors: A
authors: Lehtinen
authors: Department of Physics, P.O. Box 43, FIN-00014 University of Helsinki, Finland.
authors: Fredric
authors: F
authors: Granberg
authors: Department of Applied Physics, Aalto University School of Science, P.O. Box 11100, FIN-00076 Aalto, Espoo, Finland.
authors: Lasse
authors: L
authors: Laurson
authors: Department of Physics, P.O. Box 43, FIN-00014 University of Helsinki, Finland.
authors: Kai
authors: K
authors: Nordlund
authors: Department of Applied Physics, Aalto University School of Science, P.O. Box 11100, FIN-00076 Aalto, Espoo, Finland.
authors: Mikko J
authors: MJ
authors: Alava