High-Pressure-Induced Structural Changes in Silicate Glasses
Abstract
The technical objective of the proposed effort is to characterize and predict the compressibility and pennanent strucrnraJ changes in silicate glasses and silicate-based glass ceramics as a function of pressure. The proposed effort seeks to achieve the stated technical objective through a combination of sysuernatic experimental hydrostatic and non-hydrostatic testing (e.g., diamond anvil cell, or DAC, and indentation, respectively), structural characterization, aud utilization of radial distribution function theory. The research will focus on the characterization, interpretation, and radial distribution theory modeling of hydrostatic and non-hydrostatic responses, in addition to presstire-, stress-, time- and temperanire-dependencies of permanent structural changes (e.g., onset of densification, amount of deusification). Such responses will be correlated to intra- and inter-molecular distances and their changes. Poisson s ratio and bulk modulus will serve as the primary independent parameters, and optical-grade fused (vitreous) silica will serve as the baseline glass. Selected soda-lime silicate glasses, borosilicate glasses, and silicate-based glass ceramics will also be examined. The findings of this work will advance the understanding and predictability of how amorphous silicates and amorphous silicate matrix composites mechanically respond to high pressures. Micro- and nano-indentation, equipped with indeut-deptb-of-penetration sensors, will quantify the response of material; furthermore, the influences of the relative amounts of hydrostatic to shear stress by conducting nanoindematiou experiments with a se1ies of triangular pyramidal indenters. Physical, strucmral, and morphological characterizations will be executed on DAC- and indentation-tested glasses. Finite element modeling (FEM) will be pursued to predict spherical indentation response of any glass as a function of applied force, indenter diameter, and the glass s material properties. A gas membrane dian1ond anvil cell will be employed fur Raman spectroscopy and X-ray diffraction studies at the Advanced Photon Source (APS), Argonne National Laboratory.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 12, 2017
- Source ID
- W911NF1510614
Entities
People
- Andrew A Wereszczak
Organizations
- Army Contracting Command
- United States Army
- University of Tennessee