Dominant shear bands observed in amorphous ZrCuAl nanowires under simulated compression

TL;DR

This study uses molecular dynamics simulations to reveal size-independent shear band formation in amorphous ZrCuAl nanowires, highlighting the influence of thermal history on plasticity and surface-initiated shear bands.

Contribution

It demonstrates the formation of dominant shear bands in nanowires independent of size, emphasizing the role of surface effects and thermal history in metallic glass plasticity.

Findings

Shear bands initiate at the surfaces of nanowires.

Shear band formation reduces icosahedral short-range order.

Sample thermal history significantly affects shear band development.

Abstract

We observed the formation of dominant shear bands in model ZrCuAl metallic glass (MG) nanowires (18-nm-long) in molecular dynamics simulations, which implies size-independent incipient plasticity in MG materials. The MG nanowires were prepared using the simulated casting technique to ensure proper relaxation of sample surfaces. Under uniaxial compression, shear bands initiate at the surfaces and lead to reduced icosahedral short-range order. The shear band formation is sensitive to sample thermal-history, which calls for careful consideration of sample preparation effects in both experimental and numerical studies of size-effect in MG samples.