Structural transformations in porous glasses under mechanical loading. I. Tension

TL;DR

This study uses molecular dynamics simulations to investigate how porous glasses' structure and mechanical properties evolve under tensile stress, revealing elastic behavior and pore coalescence leading to failure.

Contribution

It provides new insights into the structural transformations and mechanical response of porous glasses during tensile loading, focusing on pore evolution and failure mechanisms.

Findings

Elastic modulus follows a power-law dependence on density at small strains.

Pores deform and coalesce into larger voids under increased strain.

System-spanning voids form, leading to material failure.

Abstract

The evolution of porous structure and mechanical properties of binary glasses under tensile loading were examined using molecular dynamics simulations. We consider vitreous systems obtained in the process of phase separation after a rapid isochoric quench of a glass-forming liquid to a temperature below the glass transition. The porous structure in undeformed samples varies from a connected porous network to a random distribution of isolated pores upon increasing average glass density. We find that at small strain, the elastic modulus follows a power-law dependence on the average glass density and the pore size distribution remains nearly the same as in quiescent samples. Upon further loading, the pores become significantly deformed and coalesce into larger voids that leads to formation of system-spanning empty regions associated with breaking of the material.