Embodiments of this disclosure pertain to a strengthened glass article including a first surface and a second surface opposing the first surface defining a thickness (t) of about less than about 1.1 mm, a compressive stress layer extending from the first surface to a depth of compression (DOC) of about 0.1.Math.t or greater, such that when the glass article fracture, it breaks into a plurality of fragments having an aspect ratio of about 5 or less. In some embodiments, the glass article exhibits an equibiaxial flexural strength of about 20 kgf or greater, after being abraded with 90-grit SiC particles at a pressure of 25 psi for 5 seconds. Devices incorporating the glass articles described herein and methods for making the same are also disclosed.

A support glass substrate of the present invention is a support glass substrate for supporting a substrate to be processed, the support glass substrate including lithium aluminosilicate-based glass, having a content of Li.sub.2O of from 0.02 mol % to 25 mol % in a glass composition, and having an average linear thermal expansion coefficient within a temperature range of from 30° C. to 380° C. of 38×10.sup.−7/° C. or more and 160×10.sup.−7/° C. or less.

A support glass substrate of the present invention is a support glass substrate for supporting a substrate to be processed, the support glass substrate including lithium aluminosilicate-based glass, having a content of Li.sub.2O of from 0.02 mol % to 25 mol % in a glass composition, and having an average linear thermal expansion coefficient within a temperature range of from 30° C. to 380° C. of 38×10.sup.−7/° C. or more and 160×10.sup.−7/° C. or less.

A glass for magnetic recording medium substrate is an amorphous oxide glass. In terms of mol %, SiO.sub.2 content ranges from 45 to 68%, Al.sub.2O.sub.3 from 5 to 20%, total content of SiO.sub.2 and Al.sub.2O.sub.3 60 to 80%, B.sub.2O.sub.3 from 0 to 5%, MgO from 3 to 28%, CaO from 0 to 18%, total content of BaO and SrO 0 to 2%, total content of alkali earth metal oxides from 12 to 30%, total content of alkali metal oxides from 3.5 to 15%, and at least one kind selected from the group made of Sn oxide and Ce oxide being included, a total content of Sn oxide and Ce oxide ranges from 0.05 to 2.00%, a glass transition temperature ≥625° C., a Young's modulus ≥83 GPa, a specific gravity ≤2.85, and an average linear expansion coefficient at 100 to 300° C.≥48×10.sup.−7/° C.

The present invention relates to a crystallized glass including: at least one crystal of indialite and cordierite, in which the crystallized glass has a total amount of the crystal is 40 mass % or more of the crystallized glass, and the crystal comprises at least one of a vacancy and a different element at an Al site.

The present invention relates to a crystallized glass including: at least one crystal of indialite and cordierite, in which the crystallized glass has a total amount of the crystal is 40 mass % or more of the crystallized glass, and the crystal comprises at least one of a vacancy and a different element at an Al site.

Scratch and damage resistant laminated glass articles are disclosed. According to one aspect, a laminated glass article may include a glass core layer formed from core glass composition and includes a core glass elastic modulus E.sub.C and at least one glass clad layer fused directly to the glass core layer. The at least one glass clad layer may be formed from an ion exchangeable clad glass composition different than the core glass composition and includes a clad glass elastic modulus E.sub.CL. The laminated glass article may have a total thickness T and the at least one glass clad layer may have a thickness T.sub.CL that is greater than or equal to 30% of the total thickness T. E.sub.C may be at least 5% greater than E.sub.CL.

Embodiments of a glass-based article including a first surface and a second surface opposing the first surface defining a thickness (t) of about 3 millimeters or less (e.g., about 1 millimeter or less), and a stress profile, wherein all points of the stress profile between a thickness range from about 0.Math.t up to 0.3.Math.t and from greater than about 0.7.Math.t up to t, comprise a tangent with a slope having an absolute value greater than about 0.1 MPa/micrometer, are disclosed. In some embodiments, the glass-based article includes a non-zero metal oxide concentration that varies along at least a portion of the thickness (e.g., 0.Math.t to about 0.3.Math.t) and a maximum central tension in the range from about 80 MPa to about 100 MPa. In some embodiments, the concentration of metal oxide or alkali metal oxide decreases from the first surface to a value at a point between the first surface and the second surface and increases from the value to the second surface. The concentration of the metal oxide may be about 0.05 mol % or greater or about 0.5 mol % or greater throughout the thickness. Methods for forming such glass-based articles are also disclosed.

Embodiments of a glass-based article including a first surface and a second surface opposing the first surface defining a thickness (t) of about 3 millimeters or less (e.g., about 1 millimeter or less), and a stress profile, wherein all points of the stress profile between a thickness range from about 0.Math.t up to 0.3.Math.t and from greater than about 0.7.Math.t up to t, comprise a tangent with a slope having an absolute value greater than about 0.1 MPa/micrometer, are disclosed. In some embodiments, the glass-based article includes a non-zero metal oxide concentration that varies along at least a portion of the thickness (e.g., 0.Math.t to about 0.3.Math.t) and a maximum central tension in the range from about 80 MPa to about 100 MPa. In some embodiments, the concentration of metal oxide or alkali metal oxide decreases from the first surface to a value at a point between the first surface and the second surface and increases from the value to the second surface. The concentration of the metal oxide may be about 0.05 mol % or greater or about 0.5 mol % or greater throughout the thickness. Methods for forming such glass-based articles are also disclosed.

A glass-ceramic article includes from 60 mol % to 72 mol % SiO2; from 2.5 mol % to 8 mol % Al.sub.2O.sub.3; from 17 mol % to 26 mol % Li.sub.2O; from 0.2 mol % to 4 mol % ZrO.sub.2; and from 0.5 mol % to 2 mol % P.sub.2O.sub.5. The sum of alkaline earth oxides and transitional metal oxides in the glass-ceramic article may be from 0.1 mol % to 6 mol %, wherein alkaline earth oxides is the sum of CaO, MgO, SrO, and BaO and transition metal oxides is the sum of La.sub.2O.sub.3, Y.sub.2O.sub.3, Ta.sub.2O.sub.5, and GeO.sub.2. The sum of P.sub.2O.sub.5 and ZrO.sub.2 in the glass-ceramic article may be from 1 mol % to 6 mol %. The glass-ceramic article may comprise a crystalline phase comprising lithium disilicate and petalite. The total amount of lithium disilicate and petalite in the crystalline phase of the glass-ceramic article may be greater than 50 wt %, based on a total weight of the crystalline phase.