Atomic Mechanisms of Structural Reconstruction of FCC Metallic Nanowires in the Process of Tension Deformation

摘要

In recent years there has been growing interest in the study of materials whose physical and mechanical properties are formed at nanometer scale and even at the scale of molecules and atoms. Such materials are called nanostructures or nanomaterials. It is accepted by many researchers that structural units of nanomaterials have characteristic size of less than 100 nm but sometimes this limit is extended up to 400 nm. Experimental study of structural changes taking place in nanomaterials under intensive external impacts and severe plastic deformation is a challenge. Atomistic computer simulations can be effectively used in parallel with theory and real experiment when deformation of nanomaterials takes place at a very high strain rate. The main computational methods used in simulations at microscale and nanoscale levels are the molecular dynamics (MD), quasistatic relaxation, and Monte-Carlo methods. These methods find many applications in the study of the peculiarities of deformation and fracture processes in nanomaterials. In particular, the processes of structural reconstruction of an ideal nanocrystal of solid Ar under homogeneous strain condition have been studied in details by the method of quasistatic relaxation in quasi three-dimensional approximation. Mechanical properties and mechanisms of plastic deformations of nanowires have been extensively studied in the recent past.