Multiscale simulation of atomic structure in the vicinity of nanovoids and evaluation of the shifting rates of the void surface elements in bcc iron and aluminum

TL;DR

This paper introduces a novel multiscale simulation method for atomic structures near nanovoids in bcc iron and aluminum, analyzing void surface dynamics and vacancy flux effects across different crystallographic directions.

Contribution

It develops a self-consistent Molecular Statics variant and models void surface shifting rates considering strain and surface energies, providing new insights into nanovoid behavior.

Findings

Displacement rates vary significantly across crystallographic directions.

<100> direction exhibits notably lower shifting rates.

Simulation results align with theoretical kinetic equations.

Abstract

We simulate structure in the vicinity of different size nanovoids using a new variant of the Molecular Statics, wherein atomic structure in the vicinity of nanovoids and the parameters that define the displacements of atoms placed in elastic continuum around main computation cell are determined in a self-consistent manner. Then we model structure of the surface of different crystallographic planes. Next, the kinetic equations for shifting rate of void surface elements located normal to the void surface are obtained. These equations take into account the dependence of the vacancy flux on strain and the surface energies of the crystallographic planes. In the next section, we apply the obtained expressions and simulation results to calculate the shifting rates of void surface elements for different crystallographic directions. Rates of displacements in different crystallographic directions for bcc and fcc metals differ significantly, and for the <100> direction they are greatly lower than for other directions.