A study on ion‐exchanged, soda‐lime glass’s residual stress relationship with K⁺/Na⁺ concentration

Abstract

In the past, studies have shown that the chemical composition within the exchanged layer could influence both the stress build‐up magnitude and the stress relaxation rate. In this work, a novel approach was proposed to estimate the relationship between the stress relaxation parameters, the dilation coefficient, and the relative K+/Na+ concentration. The proposed method required knowledge of the residual stress profiles, the molten salt bath's temperature and soaking time, and the bath's composition. Based on the analyses performed on various residual stress profiles in ion‐exchanged soda‐lime glass, both the dilation coefficient and the magnitudes of the relaxation time constants were found to consistently decrease with K2O concentration.

Mechanical, thermal, and structural investigations of chemically strengthened Na2O–CaO–Al2O3–SiO2 glasses

“…The melt viscosity is maximized around a unity molar ratio of the metal oxide to alumina (Toplis et al, 1997;Webb et al, 2007), n(M (2) O)/n(Al 2 O 3 ) = 1 [henceforth referred to as "M (2) O/Al 2 O 3 "]. Conventional soda-lime-silicate (SLS) glasses are in general unsuitable for chemical strengthening because they suffer from higher stress relaxation than high performance AS glasses (Varshneya and Kreski, 2012;Erdem et al, 2017;Güzel et al, 2019;Macrelli et al, 2019;Sun and Dugnani, 2020). Nonetheless, given that SLS glasses dominate the industrial market (Hand and Tadjiev, 2010;Deng et al, 2020), their minor doping with Al is a promising route towards an optimal balance between high chemical strengthening performance and lower production costs, and thereby more sustainable glasses (Wallenberger and Bingham, 2010;LaCourse, 2018).…”

Stress in ion exchanged soda‐lime silicate and sodium aluminosilicate glasses: Experimental and theoretical comparison

“…The number of variable parameters has been taken as limited as possible to those expected to depend on temperature (interdiffusion coefficient D, relaxation time τ and surface equilibrium concentration χ) and immersion time. Other approaches have been recently proposed by Sun and Dugnani 21 for stress relaxation modeling of ion exchanged soda-lime glass based on Prony series for the non-isochoric relaxation function, concentration-dependent relaxation times, and concentration-dependent Cooper coefficient. We have intentionally limited the number of fitting parameters to highlight the effects of the different relaxation mechanisms.…”

Modeling of ion exchange in glass considering large viscoelastic deformation and mechano–electrochemical coupling

“…With this analogy, Sane and Cooper 7 obtained an integral equation to determine the stress profile in an ion‐exchanged glass with the knowledge of the concentration distribution of invaded ions. Dugnani et al 8–11 . developed an analytical solution to Sane and Cooper's equation with the assumption of composition‐dependent stress relaxation of the glass based on a generalized Maxwell model (Prony series).…”

“…With this analogy, Sane and Cooper 7 obtained an integral equation to determine the stress profile in an ionexchanged glass with the knowledge of the concentration distribution of invaded ions. Dugnani et al [8][9][10][11] developed an analytical solution to Sane and Cooper's equa-tion with the assumption of composition-dependent stress relaxation of the glass based on a generalized Maxwell model (Prony series). Concomitantly, Varshneya et al [12][13][14][15] modified Sane and Cooper's analysis by introducing a new term to account for various relaxation effects (i.e., fast βrelaxation, slow α-relaxation, and stress release due to volume and shear viscosities) that is an account for the subsurface maximum compressive stress when the process temperature is close to or higher than T g .…”