Reversible plasticity in amorphous materials

TL;DR

This paper presents evidence of reversible plastic events at the microscopic level in amorphous materials, challenging the traditional view that plasticity is solely due to irreversible microscopic changes.

Contribution

It demonstrates reversible plasticity in amorphous materials through experiments and simulations, linking microscopic reversibility to potential energy landscape pathways.

Findings

Reversible plastic events observed in experiments and simulations.

Reversible plasticity linked to potential energy landscape pathways.

Challenges the assumption that plasticity is always irreversible.

Abstract

A fundamental assumption in our understanding of material rheology is that when microscopic deformations are reversible, the material responds elastically to external loads. Plasticity, i.e. dissipative and irreversible macroscopic changes in a material, is assumed to be the consequence of irreversible microscopic events. Here we show direct evidence for reversible plastic events at the microscopic scale in both experiments and simulations of two-dimensional foam. In the simulations, we demonstrate a link between reversible plastic rearrangement events and pathways in the potential energy landscape of the system. These findings represent a fundamental change in our understanding of materials--microscopic reversibility does not necessarily imply elasticity.