Icosahedral order, disclinations, dislocations and plastic deformation in metallic glasses

Abstract

Within the framework of concepts developed for metallic glasses as media with icosahedral coordination order containing a great number of line topological disclinations, their plastic properties are considered. It is demonstrated that moving disclination dipoles, each being equivalent to a dislocation with a variable Burgers vector, can carry plastic deformation in metallic glasses. The transition from a homogeneous mode of plastic deformation to an inhomogeneous one is explained by replacement of a thermally activated character of motion (or generation) of disclination dipoles by an athermal character of motion.