The effects of cooling rate on particle rearrangement statistics: Rapidly cooled glasses are more ductile and less reversible

TL;DR

This study reveals that rapidly cooled amorphous glasses exhibit more frequent particle rearrangements, are more ductile, and less reversible under cyclic shear compared to slowly cooled glasses, highlighting the influence of cooling rate on mechanical behavior.

Contribution

It demonstrates how cooling rate affects particle rearrangements, ductility, and reversibility in amorphous glasses, providing new insights into their mechanical response.

Findings

Rapidly cooled glasses have more frequent and larger particle rearrangements.

The shear to bulk modulus ratio decreases with increasing cooling rate.

More ductile glasses are less reversible under cyclic shear.

Abstract

Amorphous solids, such as metallic, polymeric, and colloidal glasses, display complex spatiotemporal response to applied deformations. In contrast to crystalline solids, during loading, amorphous solids exhibit a smooth crossover from elastic response to plastic flow. In this study, we investigate the mechanical response of binary Lennard-Jones glasses to athermal, quasistatic pure shear as a function of the cooling rate used to prepare them. We find several key results concerning the connection between strain-induced particle rearrangements and mechanical response. We show that more rapidly cooled glasses undergo more frequent and larger particle rearrangements than slowly cooled glasses. We find that the ratio of the shear to bulk moduli decreases with increasing cooling rate, which suggests that more rapidly cooled glasses are more ductile than slowly cooled samples. In addition, we characterized the degree of reversibility of particle motion during cyclic shear. We find that irreversible particle motion occurs even in the putative linear regime of stress versus strain. However, slowly cooled glasses, which undergo smaller rearrangements, are more reversible under cyclic shear than rapidly cooled glasses. Thus, we show that more ductile glasses are also less reversible.