Imparities of shear avalanches dynamic evolution in a metallic glass

Yin Du,Qing Zhou,Qian Jia,Yidi Shi,Haifeng Wang,Jian Wang

doi:10.1080/21663831.2020.1771450

Abstract

ABSTRACT The imparities of shear avalanches dynamic evolution under nanoindentation originating from the soft regions and the stiff matrix were explored in a metallic glass by statistical and dynamic analysis. Upon the continuous indentation process, the dynamic state of the stiff matrix exhibits a transition from a chaotic behavior to a self-organized critical (SOC) behavior, whereas the soft regions are dominated by the SOC behavior throughout the indentation process. The mechanism was clarified by the evolution of the cut-off size of shear avalanches. These findings might advance our fundamental understanding of inhomogeneous deformation on microscale.

Highlights

Owing to the attractive combination of mechanical and physical properties, metallic glasses (MGs) are gaining significant ground as structural and functional materials [1–4]
Inhomogeneous deformation of MGs stemming from the lack of a long-range atomic periodicity leads to highly-localized shear banding, giving rise to the catastrophic failure, which severely restricts the application of metallic glasses [5]
Inhomogeneous deformation of MGs is typically manifested as a series of spatiotemporal shear-banding behaviors that are known as repeat cycles of sudden stress relaxation, followed by re-accumulating elastic energy, i.e. the so-called shear avalanches or serrated flow [6–8]

Summary

Introduction

Owing to the attractive combination of mechanical and physical properties, metallic glasses (MGs) are gaining significant ground as structural and functional materials [1–4]. The shear avalanches dynamic evolution controlled by the atomic-scale rearrangement mechanism in metallic glasses strongly relies on the structural state and the history of deformation.

Results

Conclusion