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 provides a vapour deposition method for preparing an amorphous lithium borosilicate compound or doped lithium borosilicate compound, the method comprising: providing a vapour source of each component element of the compound, wherein the vapour sources comprise at least a source of lithium, a source of oxygen, a source of boron and a source of silicon, and, optionally, a source of at least one dopant element; providing a substrate at a temperature of less than about 180° C.; delivering a flow of said lithium, said oxygen, said boron and said silicon, and, optionally, said dopant element, wherein the rate of flow of said oxygen is at least about 8×10.sup.−8 m.sup.3/s; and co-depositing the component elements from the vapour sources onto the substrate wherein the component elements react on the substrate to form the amorphous compound.

The invention relates to a method for treating a silicate-type glass comprising alkali and alkaline-earth metal oxides or d.sup.10 or IIIA metal oxides, said method comprising at least the following steps: (a) incorporation of nitrogen into the surface of the glass; and (b) thermal poling treatment of the material obtained in (a), under a chemically inert controlled atmosphere. The invention also relates to the material produced by said method.

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 transparent oxynitride glass that includes aluminum, calcium, magnesium, silicon, oxygen, and nitrogen, wherein the aluminum may be provided by an aluminum source comprising about 1 wt % to about 100 wt % aluminum nitride (AlN), based on the total weight of aluminum in the oxynitride glass and/or the nitrogen may be provided by an aluminum source comprising about 1 wt % to about 100 wt % aluminum nitride (AlN), based on the total weight of nitrogen in the oxynitride glass. The oxynitride glass may be substantially free of carbon. Also provided are uses of and articles comprising the oxynitride glass and methods of making the oxynitride glass.

A glass-ceramic composition as defined herein. The glass-ceramic composition includes a first crystalline phase comprising lithium disilicate. The glass-ceramic composition can include up to 10 wt % CaO, up to 5 wt % Na.sub.2O, up to 10 wt % B.sub.2O.sub.3, and greater than 0.5 wt % ZrO.sub.2. The glass-ceramic composition can also include from 50 to 75 wt % SiO.sub.2, from 1 to 5 wt % Al.sub.2O.sub.3, from 1 to 8 wt % P.sub.2O.sub.5, and from 5 to 20 wt % Li.sub.2O. In aspects, the glass-ceramic composition can include a second crystalline phase including wollastonite, apatite, cristobalite, -quartz, lithiophosphate, or a combination thereof. Also disclosed are methods of making and using the disclosed compositions.

A hollow body includes a wall of glass which at least partially surrounds an interior volume of the hollow body. The wall of glass has a wall surface which has a surface region. At least in the surface region the wall surface has a content of N in a range from 0.3 to 10.0 at-%, and at least 5 at-% Si.

A glass composition, including contrast enhancing glass and contrast enhancing sunglass, having approximately 45-65 wt.-%, SiO2, 0-12 wt.-% B2O3, 0-15 wt.-%, Na2O, 0-10 wt.-% K2O, and 10 0-7 wt.-% ZnO, 1-12 wt.-% Nd2O3, 1-10 wt.-% Er2O3, 0.5-8 wt.-% Ho2O3, and 0.00-0.05 wt.-% NiO, and methods of making the same.

Bulk paint and ceramic powder systems, methods of forming same, and methods of forming a flexible ceramic coating on a metal substrate are disclosed. The systems may include a ceramic composition having between 2 to 30 weight percent of an alkali metal oxide, such as K.sub.2O, Na.sub.2O, and Li.sub.2O or mixtures thereof, between 10 to 74 weight percent SiO.sub.2, and between 23 to 79 weight percent B.sub.2O.sub.3. Additives that are nonwetting with molten metals, such as boron nitride, provide durable coatings for metal processing operations. The ceramic composition may include less than 5 weight percent additional metal oxides. The bulk paint system further may include water and a cellulosic suspension agent to form a bulk paint. The ceramic powder system may be processed to form a uniform powder. The bulk paint or uniform powder may be applied to a metal substrate, such as a ferrous metal substrate, dried, and heated to form a flexible coating on the metal substrate.

A transparent gahnite-spinel glass ceramic is provided. The glass ceramic includes a first crystal phase including (Mg.sub.xZn.sub.1x)Al.sub.2O.sub.4 where x is less than 1 and a second crystal phase including tetragonal ZrO.sub.2. The glass ceramic may be ion exchanged. Methods for producing the glass ceramic are also provided.