Ion-exchanged alkali aluminosilicate glass articles with a ratio of peak compressive stress value to Young's modulus value of 15 or more. The glass articles may include Al.sub.2O.sub.3 mol %+RO mol %≥17 mol %, where RO mol %=MgO mol %+CaO mol %, and be substantially free of ZnO, SrO, BaO, B.sub.2O.sub.3, P.sub.2O.sub.5, Li.sub.2O, and K.sub.2O. The glass articles may have a peak compressive stress value in a range of 500 MPa to 1300 MPa. The glass articles are suitable for various high-strength applications, including cover glass applications that experience significant bending stresses during use, for example, cover glasses for flexible displays.

Crystallized glass and strengthened crystallized glass with a novel composition, which have a high refractive index and high hardness, are provided. A crystallized glass, including, by mass % in terms of oxide, 20.0% or more and less than 40.0% of a SiO.sub.2 component, more than 0% and 20.0% or less of a Rn.sub.2O component, where Rn is one or more selected from Li, Na, and K, 7.0% to 25.0% of an Al.sub.2O.sub.3 component, 0% to 25.0% of a MgO component, 0% to 45.0% of a ZnO component, and 0% to 20.0% of a Ta.sub.2O.sub.5 component, in which a total amount of the MgO component, the ZnO component, and the Ta.sub.2O.sub.5 component is 10.0% or more.

The present invention relates to a chemically strengthened glass article including: a first surface; a second surface facing the first surface; and an end portion in contact with the first surface and the second surface, in which the first surface has a compressive stress value of 400 MPa to 1000 MPa, in which, when a compressive stress value of an inside of the glass is expressed with a depth from the first surface as a variable, a depth m [μm] at which the compressive stress value is maximum is larger than 0 μm, and a value of CS.sub.m−CS.sub.0 [MPa] is 30 MPa or more, and in which a depth DOL at which the compressive stress value is 0 is 50 μm to 150 μm.

The present invention relates to a chemically strengthened glass having a thickness of t [mm], and having a profile of a stress value CS.sub.x [MPa,] at a depth x [.Math.m] from a surface of the glass, the stress value being measured by a scattered-light photoelastic stress meter, in which a second-order differential value CS.sub.x" of the stress value CS.sub.x in the profile satisfies the following expression within a range of CS.sub.x≥0: 0<CS.sub.x"≤0.050.

A coated article is described herein that may comprise a substrate and an optical coating. The substrate may have a major surface comprising a first portion and a second portion. A first direction that is normal to the first portion of the major surface may not be equal to a second direction that is normal to the second portion of the major surface. The optical coating may be disposed on at least the first portion and the second portion of the major surface. The coated article may exhibit at the first portion of the substrate and at the second portion of the substrate hardness of about 8 GPa or greater at an indentation depth of about 50 nm or greater as measured on the anti-reflective surface by a Berkovich Indenter Hardness Test.

Strengthened glass substrates with glass fits and methods for forming the same are disclosed. According to one embodiment, the present invention provides a glass frit with a coefficient of thermal expansion less than or equal to the coefficient of thermal expansion of the glass substrate where it is going to be painted. The glass frit of the present invention has similar ion exchange properties to the glass substrate that is going to be used to paint with the glass frit allowing the glass substrate to be ion-exchanged. The glass frit of the present invention is mixed with an organic carrier.

A method of etching a substrate comprises: contacting a substrate having a thickness with an etchant disposed in a vessel for a period of time until the thickness has reduced by at least 2 μm and at an average rate of 1 μm per minute to 6.7 μm per minute, the etchant having a temperature of 170° C. to 300° C. and comprising a molten mixture of two or more alkali hydroxides; and ceasing contacting the substrate with the etchant. The etchant in some instances comprises a molten mixture of NaOH and KOH. For example, the etchant in some instances includes a molten mixture of 24 wt. % to 72 wt. % NaOH, and 76 wt. % to 28 wt. % KOH. In some instances, the method alters the weight percentage of Na.sup.+, K.sup.+ and Li.sup.+ in the composition of the surface of the substrate by less than 1%.

The purpose of the present invention is to provide a chemically-strengthened glass exhibiting both surface strength and abrasion-resistant anti-fingerprint (AFP) properties. The present invention relates to a plate-shaped chemically-strengthened glass which has a compressive stress layer provided to a glass surface layer, a glass surface hydrogen concentration profile in a specific range, and a surface strength and abrasion-resistant anti-fingerprint (AFP) properties which are in specific ranges.

To provide a crystallized glass substrate including a surface with a compressive stress layer, in which a stress depth DOL.sub.zero of the compressive stress layer, at which the compressive stress is 0 MPa, is 45 to 200 μm, a compressive stress CS on an outermost surface of the compressive stress layer is 400 to 1400 MPa, and CS×DOL.sub.zero, which is a product of the compressive stress CS on the outermost surface and the stress depth DOL.sub.zero (μm), is 4.8×10.sup.4 or more.

A display device includes a display module having a folding area and a non-folding area adjacent to the folding area. A glass substrate is disposed on the display module and comprises a first layer and a second layer disposed on the first layer. The second layer has a compressive strength that is higher than a compressive strength of the first layer. The first layer and the second layer of the glass substrate each include a folding portion overlapping the folding area and having a first thickness and a non-folding portion overlapping the non-folding area and having a second thickness greater than the first thickness. The second layer of the non-folding portion has a thickness that is greater than a thickness of the second layer of the folding portion.