title: Dislocation processes in the deformation of nanocrystalline aluminium by molecular-dynamics simulation.
abstract: The mechanical behaviour of nanocrystalline materials (that is, polycrystals with a grain size of less than 100 nm) remains controversial. Although it is commonly accepted that the intrinsic deformation behaviour of these materials arises from the interplay between dislocation and grain-boundary processes, little is known about the specific deformation mechanisms. Here we use large-scale molecular-dynamics simulations to elucidate this intricate interplay during room-temperature plastic deformation of model nanocrystalline Al microstructures. We demonstrate that, in contrast to coarse-grained Al, mechanical twinning may play an important role in the deformation behaviour of nanocrystalline Al. Our results illustrate that this type of simulation has now advanced to a level where it provides a powerful new tool for elucidating and quantifying--in a degree of detail not possible experimentally--the atomic-level mechanisms controlling the complex dislocation and grain-boundary processes in heavily deformed materials with a submicrometre grain size.
authors.affiliation: Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, Illinois 60439, USA.
authors.forename: Vesselin
authors.initials: V
authors.lastname: Yamakov
authors.forename: Dieter
authors.initials: D
authors.lastname: Wolf
authors.forename: Simon R
authors.initials: SR
authors.lastname: Phillpot
authors.forename: Amiya K
authors.initials: AK
authors.lastname: Mukherjee
authors.forename: Herbert
authors.initials: H
authors.lastname: Gleiter