Structural transformations in porous glasses under mechanical loading. II. Compression

TL;DR

This study uses molecular dynamics simulations to explore how porous glass structures respond to compression, revealing elastic behavior, pore deformation, and coalescence into resistant domains.

Contribution

It provides new insights into the mechanical response of porous glasses under compression, highlighting the effects of pore morphology and density on deformation mechanisms.

Findings

Elastic modulus increases as a power-law with density.

Pores deform and coalesce into large voids under compression.

Formation of homogeneous glass domains enhances resistance at high strain.

Abstract

The role of porous structure and glass density in response to compressive deformation of amorphous materials is investigated via molecular dynamics simulations. The disordered, porous structures were prepared by quenching a high-temperature binary mixture below the glass transition into the phase coexistence region. With decreasing average glass density, the pore morphology in quiescent samples varies from a random distribution of compact voids to a porous network embedded in a continuous glass phase. We find that during compressive loading at constant volume, the porous structure is linearly transformed in the elastic regime and the elastic modulus follows a power-law increase as a function of the average glass density. Upon further compression, pores deform significantly and coalesce into large voids leading to formation of domains with nearly homogeneous glass phase, which provides an enhanced resistance to deformation at high strain.