# Surface flaws control strain localization in the deformation of Cu$\vert$Au nanolaminates

## TL;DR

This study combines experiments and simulations to show that surface flaws significantly influence strain localization in Cu-Au nanolaminates, with implications for designing materials with controlled deformation behavior.

## Contribution

It demonstrates the role of surface flaws in strain localization and suggests that modulus-matched nanolaminates can suppress shear band formation.

## Key findings

- Strength increases as layer thickness decreases.
- Surface flaws initiate shear band nucleation.
- Contact geometry influences deformation modes.

## Abstract

We carried out matched experiments and molecular dynamics simulations of the compression of nanopillars prepared from Cu$\vert$Au nanolaminates with 25 nm layer thickness. The stress-strain behavior obtained from both techniques are in excellent agreement. Variation of the layer thickness in simulations reveals an increase of the strength with decreasing layer thickness. Pillars fail through the formation of shear bands whose nucleation we trace back to the existence of surface flaws. Our combined approach demonstrates the crucial role of contact geometry in controlling the deformation mode and suggests that modulus-matched nanolaminates should be able to suppress strain localization while maintaining controllable strength.