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In the market of the mobile cover glass, the development of chemically strengthened glass is focused on the drop resistance improvement. The cover glass which protects the display panel is a typical brittle material that the micro cracks tends to be occurred underneath a glass surface by physical impacts. The micro cracks tends to be propagated by tensile stress and it is known as a general procedures on glass breakage. In purpose of the cover glass strength improvement, compressive stress is applied to the glass surface using chemical strengthening method by ion exchange. However, since the central area of the glass is relatively subjected to tensile stress, the glass is instantly broken when the propagated cracks are reached on the tensile stress exerted area. The glass specifications have been managed for maintaining the strength using parameters of compressive stress (CS), depth of compression (DOC), and central tension (CT). However, there was no method to judge the most effective factor for impact drop resistance. In order to solve this problem, we developed a machine learning program for cover glass that can predict the breakage height based on stress and mapped evaluation data based on the measured stress profile data and the actual drop breakage simulated evaluation. Especially, eXplainable AI (XAI) method is used to identify the effective factors on drop breakage height. And the test and measurement data were applied to various chemically strengthened glass for analysis. In this study, it was possible to predict the drop breakage height only by measuring the stress profile of chemically strengthened glass. The feature value of chemically strengthened that has the most effect on the drop breakage resistance on rough surfaces was identified to be stress value at 30um in the case of alkali aluminosilicate glass. And it was proved that the drop breakage height was improved by 25% only by increasing the compressive stress at 30um depth. [ABSTRACT FROM AUTHOR]

Due to the ongoing development of urban infrastructure and higher living standards, waste glass has become a significant component of municipal solid waste that cannot be disregarded. To address this issue, researchers have been looking for sustainable solutions to establish Circular Economy best practices for the full value chain of products made of glass, particularly for waste from high-quality glass sheets. Unfortunately, most of this waste is either dumped in landfills or recycled in an open-loop manner, due to its diverse composition and low volume. However, with the advent of Industry 4.0 and 5.0 technologies, including machine-to-machine communication, artificial intelligence, Internet of Things, collaborative robots, dynamic life cycle assessment, and advanced remanufacturing techniques, it could now become possible to characterize and recover end-of-life high-quality glass sheets like chemically strengthened glasses, e.g. used in smartphone screens, real time in smart factories for use in other high-tech applications. Such smart factories can economically produce on-demand batch-size 1 products, marking a fundamental transition from conventional recycling methods to a sustainable solution. This paper delves into the integration of Industry 4.0 technologies in glass recycling research and the potential contributions of Industry 5.0, addressing its societal implications. It also introduces an intelligent method to assess and optimize the lifespan of smartphone screen glass, suggesting potential reuse or remanufacturing solutions. [Display omitted] • Challenges in traditional glass waste management and the complexities of recycling. • Recycling's contribution to resource conservation and the Circular Economy. • New methods for recovering high-value materials like Chemically Strengthened Glass. • Identification of research gaps and future directions for recovery of high-quality glass materials. • Influence of Industry 4.0 and 5.0 on advancing glass recovery practices. [ABSTRACT FROM AUTHOR]

Topography and mechano-bactericidal performance of nanoblades (NBs) with different densities on the chemically strengthened glass for civil aircraft portholes. Low-density NBs, medium-density NBs, high-density NBs, and ultra-high density NBs.

Chemically strengthened glass is commonly used for applications that require high strength, such as boat and train windshields, control towers and the like. The strengthening process provides the glass with a surface residual stress that outperforms other strengthened glass types, such as thermally toughened glass. However, its use has been limited, probably for two main reasons: its high cost compared to other strengthening method and the perceived loss of the strengthening if glass surface is damaged. With the recent developments in the field of thin glass, where chemical strengthening is the only possible pre‐stressing method, there is the opportunity to better understand the process and the procedure to make it a safe material for architectural applications. In this paper, an extensive investigation on chemically strengthened glass is presented. Different parameters are considered, such as different thicknesses and chemical strengthening process conditions. The work consists of photoelastic measurement and destructive test. The data arising from the tests are elaborated with the purpose of suggesting a method to calculate the design strength of chemically strengthened glass according to the existing design standards. It is highlighted the importance to qualify chemically strengthened glass in terms of its residual stress profile. [ABSTRACT FROM AUTHOR]

ASTM C1678 describes the state-of-the-art's fractographic techniques to estimate the fracture strength of glasses and ceramics through empirical, strength vs. fracture mirror length relationships. However, the methodology is subjective and only applicable to a few loading scenarios and relatively pristine fracture surfaces. This work presents a semi-automated, alternative approach to objectively estimate the strength of silicate glasses for ampler loading and geometric scenarios. The proposed method relies on a baseline set of fracture surface profilometry-scans gathered on samples of known strengths. A computer vision-based algorithm compares relevant, topological features extracted from the baseline set to the features on the fracture surfaces investigated. An empirical relationship based on over 2,100 fractured silicate specimens is used to compute the strength of the trial sample. The proposed scheme could accurately estimate the strength of specimens beyond the capacity of ASTM C1678, such as in chemically strengthened glasses and fracture surfaces displaying significant damage. [ABSTRACT FROM AUTHOR]

Chemically strengthened glass (also known as ion exchanged glass) is widely used for hand-held devices due to excellent mechanical strength. However, only top and bottom planar surfaces are sufficiently protected following a series of machining processes such as drilling, cutting and milling for manufacturing and assembly. Micro cracks that remain on the machined surface of the glass edges become very vulnerable to shock impact loading. In this study we suggest a novel PEALD technique to encapsulate surface defects with a 100 nm thickness layer of high-strength ceramics such as Al 2 O 3. In order to optimize PEALD parameters, we have examined best practices for testing chemically strengthened cover glasses. By conducting both Charpy impact test and 3-point bending test, it was found that impact resistance and flexural toughness of the PEALD-coated cover glass were 35%–40% and 21% higher compared to non-coated samples. Through the analysis of the state and elements of the machined surface with Al 2 O 3 (500 nm) coating it was verified that the coated layer uniformly covers the entire surface of the glass and fully infiltrates into the micro cracks. This study confirms that Al 2 O 3 ceramic coated with PEALD improves not only overall glass strength, but also overcomes the shortcomings of chemically strengthened glass machining. [ABSTRACT FROM AUTHOR]

The damage propagation and fracture process of monolithic annealed and chemically strengthened aluminosilicate (ALS) glass plates are characterized using Edge-on impact (EOI) testing technique. The EOI experiments on two types of ALS glass plates at a medium impact velocity of ∼180 m/s with spherical and cylinders steel projectiles were completed using pneumatic gas-gun. The high-speed images in shadowgraph mode during the impact process were recorded at the framing rate of 1,000,000 frames per second (fps) to visualize the fracture and damage front in annealed and strengthened glass plates. The real-time captured shadowgraphs in case of annealed glass (AG) showed that the damage front initially starts to develop from the impact end and then after traveling some distance arrested in few microseconds and measured average front velocity against cylindrical and spherical projectile was 2658.91 m/s and 1710.0 m/s, respectively. The tensile wave reflection in AG impact case against both types of projectiles was observed. In a chemically strengthened glass (CSG), the damage front shape and propagation against both types of projectiles were quite different than the AG, front traveled in a self-sustained mode due to the release of elastic stored energy with the velocity of 1746.92 m/s and 1690.12 m/s, respectively. The damage evolution curves plotted from captured high-speed images show that damage traveled slower in case of the spherical projectile which suggests that the shape of the projectile has a great influence on the fracture process of annealed and strengthened glass. The damage front shape in CSG against cylindrical projectile impact was more dominant along the glass boundaries and the spallation effect was not observed in CSG against spherical projectile impact. Additionally, the damage-free zones and fracture surfaces were studied using a scan electron microscope (SEM) from collected post-test debris to discuss the fracture process. [ABSTRACT FROM AUTHOR]

Abstract The intent of this research is to determine the tensile strength and fracture behavior of annealed and chemically strengthened aluminosilicate glass under static and dynamic loading conditions using Brazilian disk (BD) tests. Owing to high brittleness and very small failure strain of glass, this test method is preferred to indirectly measure the tensile strength by compressive loading of cylindrical specimens diametrically instead of using direct tensile test. In this study, based on the BD principle, the static tensile strength is measured by using the universal testing machine and a modified SHPB with pulse shaper technique is used to measure the dynamic tensile strength of two types of glasses. The synchronous high-speed photography in both static and dynamic tests is used to capture the damage/crack initiation, crack pattern, and failure process of BD specimens. Also, the strain-time history was recorded from gauges directly embedded on BD specimens in both tests. The test results showed that two types of glasses under investigation are the loading rate-sensitive. In the case of annealed glass (AG), the average dynamic tensile strength was increased three times from the static strength and a substantial increase in tensile strength of chemically strengthened glass (CSG) was observed at high loading rate. The high-speed images and collected glass debris during BD tests are analyzed and discussed to explain the rate-sensitivity, fracture mode and tensile failure process of two types of glasses. The high-speed video suggested that the main central crack caused the splitting or failure in AG and in case of CSG the main central crack along with multiple cracks the splitting or failure occurred. Finally, the scanning electron microscope (SEM) images of collected glass residue of (AG) and (CSG) was also studied to illustrate the brittle fracture surface, crack pattern and deformation mechanism in two types of glasses. [ABSTRACT FROM AUTHOR]

The goal of this article is to explore the dynamic mechanical behavior of annealed and chemically strengthened glass used in transparent laminated structures for buildings, armor and aerospace applications. Static compression (SC) tests were first conducted using the universal testing machine followed by dynamic compression (DC) tests at an average strain rate of 650 s −1 and 350 s −1 using modified Split Hopkinson pressure bar (SHPB) for annealed and strengthened glass, respectively. In DC tests, high-speed photography and flashlights were made synchronous with a loading pulse to spot the damage/crack initiation, propagation, and fracture process in both types of glasses. Static tests data concerning the compressive strength revealed that annealed glass (AG) showed strain rate sensitivity, in contrast to this chemically strengthened glass (CSG) showed no substantial strain-rate sensitivity. In DC tests compared to SC tests, it was found that both types of glass are rate sensitive and compressive strength remarkably increased at high strain-rate loading. The glass fracture process for both AG & CSG is also analyzed through high-speed imagery recorded during DC tests. The crack initiation, propagation, and glass debris are also discussed to explicate the failure mechanism of glass specimens. [ABSTRACT FROM AUTHOR]

Glass, particularly in architectural design, expresses lightness and modernity. By rising glass surfaces of facades in buildings with high safety requirements, glass works as security glazing. Requirements of security glazing increase constantly. However, single glass panes do not fulfil the demands on these high technology products. Thereby, laminated glass is used to solve problems of these specifications. The combination of different materials in a laminate permits the optimisation in consideration of desired structural or mechanical properties. In this case, the lamination of brittle glass with ductile polycarbonate enables innovative composite panels, which extend the range of glazing with security relevant applications. Glass‐polycarbonate composite panels are generally defined with two outer glass panes and one or more inner polycarbonate sheets, laminated with polymeric interlayers. The combination of these two materials demonstrates a more efficient alternative to common security glazing. Continuous developments in the field of thin glass result in more and more applications beyond the usage in smartphones or tablets. Large‐sized thin glasses with a nominal thickness of 2 mm or less are for some time available and already used in science or technology. Applications of thin glass in the building sector demand to analyse the required material properties and to combine thin glass panes with additional layers due to its low geometrical stiffness. An option for applications of large‐sized thin glass panes presents the lamination with polycarbonate. Thin glass panes substitute the two outer glass panes in glass‐polycarbonate composite panels. Therefore, thin glass‐polycarbonate composite panels are slighter than common laminated safety glass. Several options for using annealed thin glass and chemically strengthened thin glass in architecture and the lamination with polycarbonate are described as well as the required tests for using as laminated safety glazing and security glass with a resistance against manual attack. [ABSTRACT FROM AUTHOR]

Chemically strengthened glass has become essential in our daily lives and the demand is rapidly increasing in a variety of fields. However, the conventional cutting process is not applicable because of its tough layer with the compressive stress. To achieve higher-throughput production of the glass, we report spatially selective weakening of the compression layer by CO 2 laser scanning and provide its visualization by Raman mapping. We demonstrate cutting the scanned glass without shattering using a typical scribing wheel. Finally, we discuss the improvement in processability from the viewpoint of microscopic structures by means of thermal analysis and Raman spectroscopy. [ABSTRACT FROM AUTHOR]

The exchange of small sodium ions in silicate glass by larger potassium ions from a molten salt bath below T g produces a compressive stress on the glass surface region, which results in glass strengthening. The effects of thin film nucleation and initial growth on high stress and potassium-rich property of chemically strengthened glass substrates were investigated. Al 2 O 3 thin films were prepared on chemically strengthened glass substrates by electron beam evaporation with ion beam assisted deposition and magnetron sputtering, respectively. The crystalline structure and morphology of Al 2 O 3 thin films were studied by grazing incident X-ray diffraction and field emission scanning electron microscopy. The concentration distributions of potassium, aluminum and oxygen elements near the Al 2 O 3 film/chemically strengthened glass interface were analyzed by electron probe micro-analyser. It is shown that Al 2 O 3 films deposited on chemically strengthened glass substrates by different deposition techniques have an amorphous structure. Potassium ions outward diffusion from the chemically strengthened glass substrates are accompanied by aluminum and oxygen ions inward diffusion from the Al 2 O 3 thin films into glass during deposition. Diffusion rates of potassium, aluminum and oxygen ions are very different using different deposition techniques. Compared with the chemically strengthened glasses, the surface compressive stress and the depth of the compressive layer in the chemically strengthened glasses deposited Al 2 O 3 films decrease variously. The results show that the change of chemical composition throughout glass surface region in the Al 2 O 3 thin films deposition process can cause a change in physico-chemical and mechanical properties of chemically strengthened glasses. [ABSTRACT FROM AUTHOR]

In this paper, firstly the quasi-static bending performance of chemically strengthened alumina silicate glass plates is investigated for different glass thicknesses: 2.2, 4.0 and 6.0 mm. The flexural strength is measured using coaxial double ring experiments. The 3D Digital Image Correlation (DIC) technique is employed to measure the strain at failure. The failure probability is then assessed using the Weibull statistical distribution. Secondly, the performance of the laminated glass windows made of these chemically strengthened glass plates is evaluated quasi-statically under concentrated and distributed loadings. The effects of polymer interlayer thickness, glass and polymer type and multi-layering the polymer interlayer on the structural performance are investigated. The type and thickness of the polymer interlayer, as well as the type of loading are found to influence the fracture sequence in the glass plates and consequently the post fracture safety of the structure. The response of laminated glass specimens is then assessed under low velocity soft impacts, for velocities up to 3.3 m s −1 , using a drop tower facility. Laminated glass with a polyvinyl butyral (PVB) interlayer shows the greatest improvement in terms of peak force and absorbed energy. [ABSTRACT FROM AUTHOR]

Abstarct We present numerical experiments to test an iterative approach which can remove refraction-induced errors form scattered light tomography. Gradient scattered light tomography is the first method capable of direct non-destructive residual stress measurement in chemically strengthened glass. The method is based on an oblique incidence scattered light photoelasticity combined with an iterative approach to remove the influence of light ray bending from the scattered light method. In this article further numerical experiments are performed which demonstrated that the iterative approach grants the removal of the influence of light ray bending from stress profiles that have complicated shapes. Two classical examples of stress profiles in chemically strengthened glass were studied: (1) unusual stress profile, where the outermost layers of the surface are in tension (tensile surface stresses being 300 MPa), rather than compression; (2) relaxed compressive stresses in the outermost surface layer with a depth of 20 µm. We found that the nature and rate of convergence of the iterative process were notably different for compressive and tensile stresses. The analyzed stress profiles were taken from literature and hence are realistic representations of the ones that researchers might come across in glass science. Refraction induced reconstruction error Δ σ as a function of surface stress and incidence angle were simulated. [ABSTRACT FROM AUTHOR]

The developing flexible ultrathin glass for use in foldable displays has attracted widespread attention as an alternative to rigid electronic smartphones. However, the detailed compositional effects of chemically strengthened glass are not well understood. Moreover, the spatially resolved chemistry and depth of the compression layer of tempered glass are far from clear. In this study, commonly used X-ray spectroscopy techniques and atom probe tomography (APT) were used comparatively to investigate the distribution of constituent elements in two representative smartphone glass samples: non- and chemically tempered. APT has enabled sub-nanoscale analyses of alkali metals (Li, Na, K, and Ca) and this demonstrates that APT can be considered as an alternative technique for imaging the chemical distribution in glass for mobile applications., Competing Interests: Conflict of Interest The authors declare that they have no competing interest., (© The Author(s) 2023. Published by Oxford University Press on behalf of the Microscopy Society of America.)

- This paper proposes a new process to manufacture cover glass that overcomes a strength trade-off between the face and the edge. In the process, alkali barrier films are deposited on glass faces before an ion exchange process in order to control face stress properties without inhibiting the edge strengthening. As a demonstration of the process, alkali-alumino-silicate glass sheets with sputter-deposited SiO2 films were chemically strengthened, and then their stress properties and strengths were investigated. As a result, thicker SiO2 films cause lower face DOL (depth of strengthened layer), and it is observed that the faces have lower DOL than the edges. In strength tests corresponding to major fracture modes of smartphone cover glass, specimens with 80-100 nm films have more balanced face performance and better edge impact strengths than the no-film specimen. [ABSTRACT FROM AUTHOR]

This study deals with the thermal stress cleavage of chemically strengthened glass by CO 2 laser beam irradiation. In order to prevent breakage from external stress, the surface of chemically strengthened glass is load with compressive stress by ion-exchanging methods. Generally, thermal stress cleavage occurs because of tensile stress on the brittle material. This stress is induced by laser beam irradiation. Therefore, the compressive stress on the surface of chemically strengthened glass renders the thermal stress cleavage difficult to create. It is also difficult to introduce an initial crack on the surface. In this study, cleavage characteristics of chemically strengthened glass with a thickness of 0.7 mm are investigated experimentally. The depth of compressive stress from the surface is 33 μm. The laser used is a continuous CO 2 laser beam with a wavelength of 10.6 μm. This laser is also applied to the introduction of the initial crack at the edge of the chemically strengthened glass. Additionally, the influence of laser power and energy density on the introduction of the initial crack and the thermal stress cleavage are evaluated. From these results, in order to propagate the initial crack, the depth of the initial crack needs to exceed the depth of the compressive stress layer from the surface. The depth of the initial crack tends to increase with increasing energy density. When an initial crack is introduced along the cleaving line, the quality of the cleaved surface is poor. The quality of cleavage was improved by the introduction of an initial crack at the edge of the glass. [ABSTRACT FROM AUTHOR]

• Dynamic three-point bending tests were performed to analyze flexural behavior. • The flexural strength of Aluminosilicate glass is rate dependent. • Cracks propagate faster along in-plane than in the out-of-plane direction. • Cracks maintain an organized "V" shaped pattern during their in-plane propagation. • The compression or cantilever curl phenomenon happens late in the fracture sequence. Quasi-static and dynamic three-point bending tests were conducted to investigate the effect of loading rate on flexural strength and fracture mechanism of two types of Aluminosilicate glass specimens, i.e., annealed and chemically strengthened (CS). Dynamic tests were performed on Electromagnetic Split Hopkinson Pressure Bar (ESHPB), and a hybrid experimental-numerical methodology was adopted for analyzing results. It was established that the flexural strength of both glass types is rate sensitive. Synchronous in-plane and out-of-plane reprography revealed that cracks propagate much faster along in-plane than out-of-plane direction. The Crack system adheres to an organized "V" shape pattern, and the locus of crack initiation is also found different for both types of glasses. For annealed and CS glass, crack initiated from the dominant flaws of the tensile surface and the tensile edge, respectively. Fractography was performed to explain the characteristic features of the crack evolution process from a microscopic to a macroscopic perspective. [ABSTRACT FROM AUTHOR]

• Decreasing diffusion coefficients of alkali ions with increasing TiO 2 content in chemically strengthened glass. • Q 3 -silicate species with different bond lengths exist due to induced surface compressive stresses. • The surface Si-O-Si bond angle distribution increases with increasing ion exchange temperature. • Ti3+ exists as a minor constituent in the TiO 2 modified glasses, and its concentration depends on the TiO 2 concentration in the glass. Diffusion kinetics and structural properties of chemically strengthened titania-doped soda-lime silicate glasses were studied by depth-resolved X-ray photoelectron spectroscopy, Raman spectroscopy and spectrophotometry. The glasses were ion exchanged, whereby Na+ in the glass was replaced by K+ in a molten salt bath, at four different treatment temperatures between 350 and 500 °C. The alkali diffusion coefficient, D K-Na , and corresponding activation energy were calculated to be between 3.26×10−12 and 4.47×10−11 cm2s−1 and between 101.1 kJmol−1 and 105.6 kJmol−1, respectively. D K-Na was observed to decrease as the TiO 2 concentration was increased. Raman analysis showed Q 3 -silicate species with different bond lengths, which was attributed to surface compressive stresses, and increasing Si-O-Si bond angle with increasing ion exchange temperature. Ti3+ ions exist as a minor species in the glasses and its concentration depends on the TiO 2 content. Deconvolution of the optical absorption spectra reveals Jahn-Teller compressive distortion of the Ti3+ octahedral coordination. [ABSTRACT FROM AUTHOR]

Newly developed chemically strengthened glass, T2X-1, is demonstrated. T2X-1 has high strength and excellent ion-exchange properties. Fracture strength of T2X-1 is 20% higher than conventional Alumino-silicate glass (CX-01). T2X-1 has twice as fast ion-exchange speed and durable compressive stress against four times more Na+ contamination in molten KNO3 than conventional Alumino-silicate glass (CX-01). [ABSTRACT FROM AUTHOR]

Abstract: Conventional laminated glass has a relatively low post-fracture strength and stiffness, which imposes several constraints on the structural use of glass in buildings. This paper proposes a new generation of laminated hybrid-glass units, built-up from plies of chemically strengthened glass, conventional polymer interlayers and heat treated/annealed glass, that aim to outperform conventional laminated glass units. The paper describes the experimental investigations on the novel laminated hybrid-glass units subjected to quasi-static out-of-plane loads and presents the corresponding analytical models developed to characterise the load–deflection response of the units, both in the unfractured and post-fractured states. The experimental data shows that laminated hybrid-glass units can achieve significant post-fracture stiffness and their post-fracture strength can equal or exceed the strength at first fracture. The analytical models are successfully validated and the equivalent shear modulus approach developed in this paper facilitates future numerical analysis and optimisation of these units. [Copyright &y& Elsevier]

The use of silicate glass in engineering applications has become widespread in recent years due to its superior mechanical and optical properties. However, glass, being a brittle material, poses extremely poor resistance against fracture. Chemical strengthening through ion-exchange has emerged as a promising technique to improve its fracture resistance. In this study, the relationships between chemical strengthening parameters and the resulting fracture toughness of chemically strengthened (CS) glass are investigated using experiments, analytical and numerical simulations. Our results show that optimal fracture resistance for a CS glass requires a proper combination of chemical strengthening parameters, namely the surface compressive stress (σ C S), and depth of the compression layer (DOL). The present study establishes the fact that unlike glass, the fracture toughness (K I C C S) of a CS glass is not a constant material parameter, instead depends on the initial crack/notch length. The experimental data have also been supported with analytical calculations based on linear elastic fracture mechanics and numerical simulations based on the phase-field fracture theory. These findings provide a novel understanding towards the fracture toughness improvement of CS glass, which should facilitate their widespread engineering applications. [ABSTRACT FROM AUTHOR]