The yield of Amorphous Solids Under Stress Control at Low Temperatures

TL;DR

This paper investigates the stress-controlled yield of amorphous solids at low temperatures, revealing it as a structured process driven by mechanical instabilities, distinct from thermal fluidization, and linking it to athermal strain protocols.

Contribution

It demonstrates that low-temperature yield in amorphous solids is governed by specific mechanical instabilities, challenging previous assumptions linking it to temperature or glass transition.

Findings

Yield involves a series of mechanical instabilities.

Stress-controlled yield differs from fluidization by temperature.

Athermal quasi-static protocols predict low-temperature yield behavior.

Abstract

The yield of amorphous solids like metallic glasses under external stress was discussed asserting that it is related to the glass transition by increasing temperature, or that it can be understood using statistical theories of various sorts. Here we study the approach to stress-controlled yield and argue that neither assertions can be supported, at least at low temperatures. The yield of amorphous solids at low temperatures is a highly structured phenomenon, characterized by a specific series of mechanical instabilities, and having no similarity at all to fluidization by increased temperature, real or fictive. The series of instabilities followed by stress controlled yield at low but finite temperature protocols can be predicted by analyzing athermal quasi-static strain controlled protocols, making the latter highly relevant for the deep understanding of the mechanical properties of amorphous solids.