Effect of composition and pressure on the shear strength of sodium silicate glasses: An atomic scale simulation study

Abstract

The elastoplastic behavior of sodium silicate glasses is studied at different scales as a function of composition and pressure, with the help of quasistatic atomistic simulations. The samples are first compressed and then sheared at constant pressure to calculate yield strength and permanent plastic deformations. Changes occurring in the global response are then compared to the analysis of local plastic rearrangements and strain heterogeneities. It is shown that the plastic response results from the succession of well-identified localized irreversible deformations occurring in a nanometer-size area. The size and the number of these local rearrangements, as well as the amount of internal deviatoric and volumetric plastic deformation, are sensitive to the composition and to the pressure. In the early stages of the deformation, plastic rearrangements are driven by sodium mobility. Consequently, the elastic yield strength decreases when the sodium content increases, and the same when pressure increases. Finally, good correlation was found between global and local stress-strain relationships, reinforcing again the role of sodium ions as local initiators of the plastic behavior observed at larger scales.

Hydrodynamic approaches in relativistic heavy ion reactions

“…For the recent studies, see Refs. [130,[159][160][161]. In addition, the bulk viscosity is expected to be fairly large near the critical point, and for a quantitative analysis of experimental data, its effect should not be neglected [159,[162][163][164][165][166][167][168]].…”

Plastic response of amorphous silicates, from atomistic simulations to experiments – A general constitutive relation

“…We have therefore derived an analytical expression for the yield criterion as a function of pressure. The flow data obtained in the simulations have not been directly used for the constitutive relation but it was found that assuming associated plasticity we obtained a reasonable rendering of the computed irreversible strains (Molnár et al (2017b); Molnár et al (2016a)).…”

Distribution of Sodium and Diffusion Mechanism in Sodium Silicate Liquid

“…Glass-forming mixtures of SiO2 with an alkali oxide are the important materials group that has been widely applied in many fields such as: microelectronics, medicine (bio-material), high technology materials. Therefore, understanding their structure and dynamical properties is fundamentally necessary [1][2][3]. By using the neutron, X-ray diffraction (XRD) techniques, magic-angle spinning (MAS) nuclear magnetic resonance (NMR) [4,5] and simulation methods [6,7] observed the change in structure of alkali silicate.…”