Intermittent in-situ high-resolution X-ray microscopy of 400-nm porous glass under uniaxial compression: study of pore changes and crack formation

TL;DR

This study employs in-situ nano-CT imaging and computational modeling to analyze pore evolution and crack formation in 400-nm porous glass under uniaxial compression, revealing damage mechanisms and deformation patterns.

Contribution

It introduces a combined experimental and numerical approach using nano-CT and phase-field modeling to study damage in porous glass at nanometric resolution.

Findings

Identification of pore and strut shape changes during compression

Observation of shear deformation bands and crack propagation

Validation of numerical models with experimental data

Abstract

The properties of porous glasses and their field of application strongly depend on the characteristics of the void space. Understanding the relationship between their porous structure and failure behaviour can contribute to the development of porous glasses with long-term reliability optimized for specific applications. In the present work, we used X-ray computed tomography with nanometric resolution (nano-CT) to image a controlled pore glass (CPG) with 400 nm-sized pores whilst undergoing uniaxial compression in-situ to emulate a stress process. Our results show that in-situ nano-CT provides an ideal platform for identifying the mechanisms of damage within glass with pores of 400 nm, as it allowed the tracking of the pores and struts change of shape during compression until specimen failure. We have also applied computational tools to quantify the microstructural changes within the CPG sample by mapping the displacements and strain fields, and to numerically simulate the behaviour of the CPG using a Fast Fourier Transform/phase-field method. Both experimental and numerical data show local shear deformation, organized along bands, consistent with the appearance and propagation of +/- 45 degrees cracks.