# Shear banding in metallic glasses described by alignments of Eshelby quadrupoles

## TL;DR

This paper investigates shear band formation in metallic glasses, revealing sinusoidal density variations linked to quadrupolar stress alignments, and presents a continuum mechanics model suggesting a universal deformation mechanism.

## Contribution

It introduces a continuum mechanics model based on quadrupolar stress alignments to explain shear banding in metallic glasses, supported by microstructural evidence across different types.

## Key findings

- Sinusoidal density variations are characteristic of shear bands.
- The deformation mechanism is consistent across various metallic glasses.
- A continuum mechanics model explains shear band formation through quadrupolar stress alignments.

## Abstract

Plastic deformation of metallic glasses performed well below the glass transition temperature leads to the formation of shear bands as a result of shear localization. It is believed that shear banding originates from individual stress concentrators having quadrupolar symmetry. To elucidate the underlying mechanisms of shear band formation, microstructural investigations were carried out on sheared zones using transmission electron microscopy. Here we show evidence of a characteristic signature present in shear bands manifested in the form of sinusoidal density variations. We present an analytical solution for the observed post-deformation state derived from continuum mechanics using an alignment of quadrupolar stress field perturbations for the plastic events. Since we observe qualitatively similar features for three different types of metallic glasses that span the entire range of characteristic properties of metallic glasses, we conclude that the reported deformation behavior is generic for all metallic glasses, and thus has far-reaching consequences for the deformation behavior of amorphous solids in general.