Molecular dynamics simulation of twin boundary effect on deformation of Cu nanopillars

TL;DR

This study uses molecular dynamics simulations to explore how twin boundaries influence deformation mechanisms in Cu nanopillars, revealing a shift from twinning to slip due to dislocation interactions.

Contribution

It demonstrates how twin boundaries alter deformation modes in Cu nanopillars, providing insights into nanoscale plasticity mechanisms.

Findings

Deformation in single crystal Cu nanopillars is dominated by twinning.

Introduction of twin boundary shifts deformation mode to slip.

Stair-rod dislocation formation explains the change in behavior.

Abstract

Molecular dynamics simulations performed on <110> Cu nanopillars revealed significant difference in deformation behavior of nanopillars with and without twin boundary. The plastic deformation in single crystal Cu nanopillar without twin boundary was dominated by twinning, whereas the introduction of twin boundary changed the deformation mode from twinning to slip consisting of leading partial followed by trailing partial dislocations. This difference in deformation behavior has been attributed to the formation of stair-rod dislocation and its dissociation in the twinned nanopillars.