Atomistic origins of deformation-induced structural anisotropy in metaphosphate glasses and its influence on mechanical properties

Abstract

Glasses are generally isotropic. However, structural anisotropy can be induced through processing. Here, molecular dynamics simulations were used to study the deformation behavior of metaphosphate glasses and the atomistic origins of the deformation-induced structural anisotropy. The anisotropy observed in the metaphosphate glasses originates from a preferred orientation of the tetrahedral units at both short- and medium-range, depending on the loading mode. The mechanical behavior of the glasses showed that the Young’s modulus of the anisotropic glasses is lower than that of pristine glasses. Pre-deformed glass shows a clear directional dependence with respect to the axis of the pre-deformation. In general, the Young’s moduli of the pre-deformed glasses are lower than those of pristine glasses. These findings provide insights into the origin of deformation-induced anisotropy in metaphosphate glasses and its influence on their mechanical properties, thus providing important insight for the rational design of oxide glasses with tailored material properties.