A glass ceramic material is disclosed that includes a residual glass, and a crystalline phase that includes a yoshiokaite phase. The yoshiokaite phase constitutes a main crystalline phase of the glass ceramic material. A method for making a glass ceramic material is also disclosed that includes heat treating frit glass to form the glass ceramic material, wherein the frit glass comprises: SiO.sub.2 from 15 mol % to 37 mol %; Al.sub.2O.sub.3 from 40 mol % to 47 mol %; and CaO from 20 mol % to 30 mol %.

Embodiments of the present invention pertain to antimicrobial glass compositions, glasses and articles. The articles include a glass, which may include a glass phase and a cuprite phase. In other embodiments, the glasses include as plurality of Cu.sup.1+ ions, a degradable phase including B2O3, P.sub.2O.sub.5 and K.sub.2O and a durable phase including SiO.sub.2. Other embodiments include glasses having a plurality of Cu.sup.1+ ions disposed on the surface of the glass and in the glass network and/or the glass matrix. The article may also include a polymer. The glasses and articles disclosed herein exhibit a 2 log reduction or greater in a concentration of at least one of Staphylococcus aureus, Enterobacter aerogenes, Pseudomonas aeruginosa bacteria, Methicillin Resistant Staphylococcus aureus, and E. coli, under the EPA Test Method for Efficacy of Copper Alloy as a Sanitizer testing condition and under Modified JIS Z 2801 for Bacteria testing conditions.

The invention relates to glass articles suitable for use as electronic device housing/cover glass which comprise a glass ceramic material. Particularly, a cover glass comprising an ion-exchanged glass ceramic exhibiting the following attributes (1) optical transparency, as defined by greater than 90% transmission at 400-750 nm; (2) a fracture toughness of greater than 0.6 MPa.Math.m.sup.1/2; (3) a 4-point bend strength of greater than 350 MPa; (4) a Vickers hardness of at least 450 kgf/mm.sup.2 and a Vickers median/radial crack initiation threshold of at least 5 kgf; (5) a Young's Modulus ranging between about 50 to 100 GPa; (6) a thermal conductivity of less than 2.0 W/m C., and (7) and at least one of the following attributes: (i) a compressive surface layer having a depth of layer (DOL) greater and a compressive stress greater than 400 MPa, or, (ii) a central tension of more than 20 MPa.

The invention relates to glass ceramics and glasses with a europium content, containing the following components:

TABLE-US-00001 Component wt.-% SiO.sub.2 30.0 to 75.0 Al.sub.2O.sub.3 10.0 to 45.0 Europium, calculated as Eu.sub.2O.sub.3 0.05 to 5.0
and which are suitable in particular for the production of restorations, the fluorescence properties of which largely correspond to those of natural teeth.

Glass compositions and glass fibers having low dielectric constants and low dissipation factors that may be suitable for use in electronic applications and articles are disclosed. The glass fibers and compositions of the present invention may include between 48.0 to 58.0 weight percent SiO.sub.2; between 15.0 and 26.0 weight percent B.sub.2O.sub.3; between 12.0 and 18.0 weight percent Al.sub.2O.sub.3; between greater than 0.25 and 3.0 weight percent P.sub.2O.sub.5; between greater than 0.25 and 7.00 weight percent CaO; 5.0 or less weight percent MgO; between greater than 0 and 1.5 weight percent SnO.sub.2; and 6.0 or less weight percent TiO.sub.2. Further, the glass composition has a glass viscosity of 1000 poise at a temperature greater than 1350 degrees Celsius and a liquidus temperature greater than 1000 degrees Celsius.

Composite materials are provided which include a glass-ceramic matrix composition that is lightly crystallized, a fiber reinforcement within the glass-ceramic matrix composition which remains stable at temperatures greater than 1400 C., and an interphase coating formed on the fiber reinforcement. A method of making a composite material is also provided, which includes applying heat and pressure to a shape including fiber reinforcements and glass particles. The heat and pressure lightly crystallize a matrix material formed by the heat and pressure on the glass particles, forming a thermally stable composite material.

An opaque gahnite-spinel glass ceramic is provided. The glass ceramic includes a first crystal phase including (Mg.sub.xZn.sub.1-x)Al.sub.2O.sub.4 where x is less than 1 and a second crystal phase includes at least one of tetragonal ZrO.sub.2, MgTa.sub.2O.sub.6, mullite, and cordierite. The glass ceramic has a Young's modulus greater than or equal to 90 GPa, and has a hardness greater than or equal to 7.5 GPa. The glass ceramic may be ion exchanged. Methods for producing the glass ceramic are also provided.

A seal composition includes a first alkaline earth metal oxide, a second alkaline earth metal oxide which is different from the first alkaline earth metal oxide, aluminum oxide, and silica in an amount such that molar percent of silica in the composition is at least five molar percent greater than two times a combined molar percent of the first alkaline earth metal oxide and the second alkaline earth metal oxide. The composition is substantially free of phosphorus oxide. The seal composition forms a glass ceramic seal which includes silica containing glass cores located in a crystalline matrix comprising barium aluminosilicate, and calcium aluminosilicate crystals located in the glass cores.

A glass-ceramic seal for ionic transport devices such as solid oxide fuel cell stacks or oxygen transport membrane applications. Preferred embodiments of the present invention comprise glass-ceramic sealant material based on a Barium-Aluminum-Silica system, which exhibits a high enough coefficient of thermal expansion to closely match the overall CTE of a SOFC cell/stack (preferably from about 11 to 12.8 ppm/ C.), good sintering behavior, and a very low residual glass phase (which contributes to the stability of the seal).

The present application provides LAS type transparent glass-ceramics of -quartz of composition containing a high content of zinc, articles constituted at least in part of said glass-ceramics, glasses precursors of said glass-ceramics (with a low viscosity at high temperature), and also a method of preparing said articles. Said glass-ceramics present a composition, free of arsenic oxide and antimony oxide, except for inevitable traces, expressed as percentages by weight of oxides, containing: 64.5% to 66.5% of SiO.sub.2; 19.0% to 20.6% of Al.sub.2O.sub.3; 3.0% to 3.6% of Li.sub.2O; 0 to 1% of MgO; 1.7% to 3.4% of ZnO; 2% to 3% of BaO; 0 to 3% of SrO; 0 to 1% of CaO; 2% to 4% of TiO.sub.2; 1% to 2% of ZrO.sub.2; 0 to 1% of Na.sub.2O; 0 to 1% of K.sub.2O; with Na.sub.2O+K.sub.2O+BaO+SrO+CaO6%; optionally up to 2% of at least one fining agent comprising SnO.sub.2; and optionally up to 2% of at least one coloring agent.