Sub-micron strain analysis of local stick-slip motion of individual shear bands in a bulk metallic glass

TL;DR

This study uses nanodot deposition and digital image correlation to analyze sub-micron strain fields during shear band propagation in a bulk metallic glass, revealing localized deformation and stick-slip behavior at nanometer scales.

Contribution

It introduces a high-resolution method to quantify local strain fields in metallic glasses, demonstrating the nanoscale stick-slip motion of shear bands during deformation.

Findings

Deformation is highly localized at shear bands.

Alternating regions with opposite shear strains are observed.

Shear band propagation exhibits stick-slip behavior at sub-micron scales.

Abstract

Nanodot deposition on a side surface of a rectangular sample and digital image correlation are used to quantify the in-plane strain fields associated with the propagation of a shear band in a PdNiP bulk metallic glass,induced by rolling. Within the resolution of the method related to an average inter-dot distance of 100 nm, deformation is found to be highly localized at the shear bands, while alternating areas with a size of 100 - 400 nm with opposite local shear strains are found. This phenomenon substantiates a local stick-slip nature of shear band propagation during the metallic glass deformation, even during rolling.