The present invention provides a cover glass for a display, having high durability to slow cracking and strong abraded strength even though a compressive stress is large and a depth of a compressive stress layer is deep. The present invention relates to a cover glass for a display, in which a depth of a compressive stress layer (DOL) is 30 μm or more, a surface compressive stress is 300 MPa or more, a position (HW) at which a compressive stress is half of a value of the surface compressive stress is a position of 8 μm or more from a glass surface, and the depth of the compressive stress layer (DOL) and the position (HW) at which the compressive stress is half of the value of the surface compressive stress satisfy the following formula:

0.05≦HW/DOL≦0.23  (1).

According to one embodiment, a glass composition may include from 67 mol. % to about 75 mol. % SiO.sub.2; from about 6 mol. % to about 10 mol. % Al.sub.2O.sub.3; and from about 5 mol. % to about 12 mol. % alkali oxide. The alkali oxide may include K.sub.2O in an amount less than or equal to 0.5 mol. %. The glass composition may further include from about 9 mol. % to about 15 mol. % of alkaline earth oxide. The alkaline earth oxide may include greater than about 0 mol. % and less than or equal to 3 mol. % MgO, from 2 mol. % to about 7 mol % CaO, at least one of SrO and BaO. The glass composition may further include less than 1 mol. % B.sub.2O.sub.3. A ratio of a concentration of MgO to the sum of the concentration of divalent cations (MgO:ΣRO) may be less than 0.3.

Glasses with compressive stress profiles that allow higher surface compression and deeper depth of layer (DOL) than is allowable in glasses with stress profiles that follow the complementary error function at a given level of stored tension. In some instances, a buried layer or local maximum of increased compression, which can alter the direction of cracking systems, is present within the depth of layer. Theses compressive stress profiles are achieved by a three step process that includes a first ion exchange step to create compressive stress and depth of layer that follows the complimentary error function, a heat treatment at a temperature below the strain point of the glass to partially relax the stresses in the glass and diffuse larger alkali ions to a greater depth, and a re-ion-exchange at short times to re-establish high compressive stress at the surface.

A white glass contains, in terms of mole percentage on the basis of the following oxides, from 50 to 80% of SiO.sub.2, from 0 to 10% of Al.sub.2O.sub.3, from 11 to 30% of MgO, from 0 to 15% of Na.sub.2O and from 0.5 to 15% of P.sub.2O.sub.5.

There is an article of manufacture. The article includes an alkali aluminosilicate glass object. The glass object is characterized by having at least one of: a surface compression of ≥about 100,000 psi with a case depth of ≥about 600 microns; and/or a compressive stress of ≥about 30,000 psi at ≥about 50 microns below a surface of the glass object and above the case depth.

Ion exchangeable glasses containing SiO.sub.2, Al.sub.2O.sub.3, Na.sub.2O, MgO, B.sub.2O.sub.3, and P.sub.2O.sub.5 are provided. The compressive stresses of these ion exchanged glasses are greater than 900 megapascals (MPa) at a depth of 45 or 50 microns (μm) with some glasses exhibiting a compressive stress of at least 1 gigaPascals (GPa). The ion exchange rates of these glasses are much faster than those of other alkali aluminosilicate glasses and the ion exchanged glass is resistant damage to impact damage. A method of ion exchanging the glass is also provided.

A tempered glass of the present invention includes, as a glass composition, in terms of mass %, 45 to 75% of SiO.sub.2, 0 to 30% of Al.sub.2O.sub.3, and 0 to 30% of Li.sub.2O+Na.sub.2O+K.sub.2O and has a β-OH value of 0.3 to 1/mm.

A strengthened glass container or vessel such as, but not limited to, vials for holding pharmaceutical products or vaccines in a hermetic and/or sterile state. The strengthened glass container undergoes a strengthening process that produces compression at the surface and tension within the container wall. The strengthening process is designed such that the tension within the wall is great enough to ensure catastrophic failure of the container, thus rendering the product unusable, should sterility be compromised by a through-wall crack. The tension is greater than a threshold central tension, above which catastrophic failure of the container is guaranteed, thus eliminating any potential for violation of pharmaceutical integrity.

The present invention relates to a substrate comprising an ion-implanted layer, for example a cation, wherein the ion implanted layer has a substantially uniform distribution of the implanted ions at a significantly greater depth than previously possible, to a well-defined and sharp boundary within the substrate. The invention further comprises said substrate wherein the substrate is a silicon based substrate, such as glass. The invention also comprises the use of said material as a waveguide and the use of said material in measurement devices.

Ion exchangeable glasses containing SiO.sub.2, Al.sub.2O.sub.3, Na.sub.2O, MgO, B.sub.2O.sub.3, and P.sub.2O.sub.5 are provided. The compressive stresses of these ion exchanged glasses are greater than 900 megapascals (MPa) at a depth of 45 or 50 microns (μm) with some glasses exhibiting a compressive stress of at least 1 gigaPascals (GPa). The ion exchange rates of these glasses are much faster than those of other alkali aluminosilicate glasses and the ion exchanged glass is resistant damage to impact damage. A method of ion exchanging the glass is also provided.