Internal atomic stress near Σ5 tilt grain boundary in aluminium under tension

Abstract

It is important to clarify the mechanical properties of inhomogeneous structures from the viewpoint of atomic scale to understand the mechanical behaviour of microscopic materials. Thus, the mechanical properties of local regions with inhomogeneous and non-uniform structure have been intensively investigated on the basis of the atomic stress and the elastic constant. In this study, in order to examine the mechanical behaviour of local regions under external load, we conduct atomic tensile simulations on a Σ5-(013) tilt grain boundary in aluminium using the many-body effective medium theory potential function. The structure of the grain boundary consists of two types of atomic layers, one of which has a higher elastic constant near the grain boundary and the other has a lower one. Although the grain boundary consists of identical atomic species, the local region near the grain boundary displays the mechanical properties similar to those of a composite material.