title: Cross-Split of Dislocations: An Athermal and Rapid Plasticity Mechanism.
abstract: The pathways by which dislocations, line defects within the lattice structure, overcome microstructural obstacles represent a key aspect in understanding the main mechanisms that control mechanical properties of ductile crystalline materials. While edge dislocations were believed to change their glide plane only by a slow, non-conservative, thermally activated motion, we suggest the existence of a rapid conservative athermal mechanism, by which the arrested edge dislocations split into two other edge dislocations that glide on two different crystallographic planes. This discovered mechanism, for which we coined a term "cross-split of edge dislocations", is a unique and collective phenomenon, which is triggered by an interaction with another same-sign pre-existing edge dislocation. This mechanism is demonstrated for faceted α-Fe nanoparticles under compression, in which we propose that cross-split of arrested edge dislocations is resulting in a strain burst. The cross-split mechanism provides an efficient pathway for edge dislocations to overcome planar obstacles.
authors.affiliation: Department of Mechanical Engineering, Technion - Israel Institute of Technology, 32000, Haifa, Israel.
authors.forename: Roman
authors.initials: R
authors.lastname: Kositski
authors.affiliation: Department of Materials Science and Engineering, Technion - Israel Institute of Technology, 32000, Haifa, Israel.
authors.forename: Oleg
authors.initials: O
authors.lastname: Kovalenko
authors.affiliation: Department of Materials Science and Engineering &Institute of Materials Science, University of Connecticut, CT, United States.
authors.forename: Seok-Woo
authors.initials: SW
authors.lastname: Lee
authors.affiliation: Division of Engineering and Applied Science, California Institute of Technology Pasadena, CA 91125, United States.
authors.forename: Julia R
authors.initials: JR
authors.lastname: Greer
authors.affiliation: Department of Materials Science and Engineering, Technion - Israel Institute of Technology, 32000, Haifa, Israel.
authors.forename: Eugen
authors.initials: E
authors.lastname: Rabkin
authors.affiliation: Department of Mechanical Engineering, Technion - Israel Institute of Technology, 32000, Haifa, Israel.
authors.forename: Dan
authors.initials: D
authors.lastname: Mordehai