A composition includes 30 mol % to 60 mol % SiO.sub.2; 15 mol % to 40 mol % Al.sub.2O.sub.3; 5 mol % to 25 mol % Y.sub.2O.sub.3; 5 mol % to 15 mol % TiO.sub.2; and 0.1 mol % to 15 mol % RO, such that RO is a sum of MgO, CaO, SrO, and BaO.

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 dental restorations, the fluorescence properties of which largely correspond to those of natural teeth.

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.

The present invention relates to glass-ceramic/silver composite precursor compositions in the form of powders, and to glass-ceramics/silver composite materials produced therefrom. Such materials find particular use as interconnect materials for high temperature electrochemical conversion devices such as solid oxide fuel cells (SOFCs) and solid oxide electrolysis cells (SOECs).

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.

A composition includes 30 mol % to 60 mol % SiO.sub.2; 15 mol % to 40 mol % Al.sub.2O.sub.3; 5 mol % to 25 mol % Y.sub.2O.sub.3; 5 mol % to 15 mol % TiO.sub.2; and 0.1 mol % to 15 mol % RO, such that RO is a sum of MgO, CaO, SrO, and BaO.

A silicate-based composition includes, in mol.%: 35-65% SiO.sub.2, 20-40% CaO, 10-30% Na.sub.2O, 0-15% TiO.sub.2, >0-15% Al.sub.2O.sub.3, 0-10% P.sub.2O.sub.5, 0-15% ZrO.sub.2, and 0-3% SnO.sub.2. A method of forming a silicate-based composition includes ceramming a silicate-based composition such that the ceramming is a cycle has a first portion and a second portion, with the first portion conducted at a first temperature for a first time and the second portion conducted at a second temperature for a second time.

The present invention relates to compositions in the form of precursor glass powders, pastes and preforms comprising said precursor glass powders, and glass-ceramics produced from the precursor glass powders, pastes or preforms. The present invention also relates to a method of forming a seal between a first and second material with a glass-ceramic, and a joint comprising a first material, a second material and a glass-ceramic sealing material joining the first and second materials together.

A transparent colored glass ceramic, in particular an LAS glass ceramic, suitable for use as a cooking surface is provided. The transparent colored glass ceramic includes high-quartz solid solution (HQ s.s.) as a main crystal phase and exhibits thermal expansion of −1 to +1 ppm/Kin the range from 20° C. to 700° C. The glass ceramic has from 3.0 to 3.6 percent by weight of lithium oxide (Li.sub.2O) as constituents and either is colored with 0.003 to 0.05 percent by weight of vanadium oxide (V.sub.2O.sub.5) or is colored with 0.003 to 0.25 percent by weight of molybdenum oxide (MoO.sub.3).

A glass-ceramic article comprises: a center-volume composition comprising (on an oxide basis): 55-75 mol % SiO.sub.2; 0.2-10 mol % Al.sub.2O.sub.3; 0-5 mol % B.sub.2O.sub.3; 15-30 mol % Li.sub.2O; 0-2 mol % Na.sub.2O; 0-2 mol % K.sub.2O; 0-5 mol % MgO; 0-2 mol % ZnO; 0.2-3.0 mol % P.sub.2O.sub.5; 0.1-10 mol % ZrO.sub.2; 0-4 mol % TiO.sub.2; and 0-1.0 mol % SnO.sub.2. Lithium disilicate and either β-spodumene or β-quartz are the two predominant crystalline phases (by weight) of the glass-ceramic article. The glass-ceramic article further comprises tetragonal ZrO.sub.2 as a crystalline phase. The composition of the glass-ceramic article from a primary surface into a thickness of the glass-ceramic article can comprise over 10 mol % Na.sub.2O (on an oxide basis), with the mole percentage of Na.sub.2O decreasing from the primary surface towards the center-volume. The glass-ceramic article exhibits a ring-on-ring load-to-failure of at least 120 kgf, when the thickness of the glass-ceramic article is 0.3 mm to 2.0 mm.