Abstract: A cover glass is provided that includes a silica based glass ceramic with a thickness between 0.4 mm and 0.85 mm. The glass ceramic has a transmittance of more than 80% from 380 nm to 780 nm and a stress attribute selected from: an overall compressive stress (CS) of at least 250 MPa and at most 1500 MPa, a compressive stress at a depth of 30 ?m (CS30) from one of the two faces of at least 160 MPa and at most 525 MPa, a depth of the compression layer (DoCL) of at least 0.2 times the thickness and less than 0.5 times the thickness, and any combinations thereof. The glass ceramic has at least one silica based crystal phase having in a near-surface layer a unit cell volume of at least 1% by volume larger than that of a core where the crystal phase has minimum stresses.

Abstract: A cover glass made of a glass ceramic that is silica based and has a main crystal phase of high quartz solid solution or keatite solid solution is provided. The cover glass has a stress profile with at least one inflection point at a depth of the cover glass of more than 10 ?m, a thickness from 0.1 mm to 2 mm, and a chemical tempering structure with a surface compressive stress of at least 250 MPa and at most 1500 MPa. A process for producing the cover glass is provided that includes producing a silica based green glass, hot shaping the silica based green glass, thermally treating the silica based green glass with a nucleation step and a ceramization step, and performing an ion exchange at an exchange bath temperature for a duration of time in an exchange bath.

Abstract: A cover glass is provided that includes a silica based glass ceramic with a thickness between 0.4 mm and 0.85 mm. The glass ceramic has a transmittance of more than 80% from 380 nm to 780 nm and a stress attribute selected from: an overall compressive stress (CS) of at least 250 MPa and at most 1500 MPa, a compressive stress at a depth of 30 ?m (CS30) from one of the two faces of at least 160 MPa and at most 525 MPa, a depth of the compression layer (DoCL) of at least 0.2 times the thickness and less than 0.5 times the thickness, and any combinations thereof. The glass ceramic has at least one silica based crystal phase having in a near-surface layer a unit cell volume of at least 1% by volume larger than that of a core where the crystal phase has minimum stresses.

Abstract: A highly crystalline transparent, translucent or opaque lithium aluminium silicate (LAS) glass-ceramic which has a proportion of residual glass phase of less than 20% by weight and also the use thereof is described.

Abstract: The present invention relates to an improved cordierite glass-ceramic. In order to improve the materials properties, it is proposed that the glass-ceramic comprising SiO2, Al2O3, MgO and Li2O contains cordierite as main crystal phase and that a secondary crystal phase of the glass-ceramic comprises high-quartz solid solution and/or keatite solid solution. The invention further relates to a process for producing such a glass-ceramic and the use of such a glass-ceramic.

Abstract: The present invention relates to an improved cordierite glass-ceramic. In order to improve the materials properties, it is proposed that the glass-ceramic comprising SiO2, Al2O3, MgO and Li2O contains cordierite as main crystal phase and that a secondary crystal phase of the glass-ceramic comprises high-quartz solid solution and/or keatite solid solution. The invention further relates to a process for producing such a glass-ceramic and the use of such a glass-ceramic.

Abstract: A highly crystalline transparent, translucent or opaque lithium aluminium silicate (LAS) glass-ceramic which has a proportion of residual glass phase of less than 20% by weight and also the use thereof is described.

Abstract: A glass having excellent resistance against surface damages is provided. The glass includes a content of alkaline earth oxides of at least 0.3% by weight and of P2O5 of 0.1 to 4% by weight; the glass has at least one surface that has precipitations with a mean size of 1 to 20 ?m. A method is further provided and includes melting a glass batch, yielding a glass melt, and casting the glass melt onto a float bath. The glass melt is maintained on the float bath at a temperature of above 1000° C. for at least 5 minutes, and yields glass. The glass has a content of alkaline earth oxides of at least 0.3% by weight and of P2O5 of 0.1 to 4% by weight, and the glass has at least one surface that has precipitations with a mean size of 1 to 20 ?m.

Abstract: A method is described for making a float glass convertible into a glass ceramic, by which a largely crystal fault-free glass can be produced. In this method the glass is cooled from a temperature (TKGmax), at which a crystal growth rate is at a maximum value (KGmax), to another temperature (TUEG), at which practically no more crystal growth occurs, with a cooling rate, KR, in ° C. min?1 according to: KR UEG KGmax ? ? ? ? T UEG KGmax 100 · KG ? ? max , wherein ?T=TKGmax?TUEG, and KGmax=maximum crystal growth rate in ?m min?1. The float glass has a thickness below an equilibrium thickness, a net width of at least 1 m and has no more than 50 crystals with a size of more than 50 ?m, especially no crystals with a size of more than 10 ?m, per kilogram of glass within the net width.

Abstract: A glass-ceramic which is particularly suitable as dielectric for use in the high-frequency range, in particular as dielectric resonator, as electronic frequency filter element or as antenna element is disclosed. The glass-ceramic has at least the following constituents (in mol % on an oxide basis): 5-50% of SiO2, 0-20% of Al2O3, 0-25% of B2O3, 0-25% of BaO, 10-60% of TiO2, 5-35% of Re2O3, where Ba can be partly replaced by Sr, Ca, Mg, where Re is a lanthanide or yttrium and where Ti can be partly replaced by Zr, Hf, Y, Nb, V, Ta.

Abstract: A process for the production of a glass-ceramic comprises the following steps: a) providing a mixture comprising at least SiO2, Al2O3, BaO and TiO2, b) melting the mixture in order to produce a glass phase, c) cooling the glass phase, and d) ceramicizing the glass phase. In the process, the glass phase is heated over the course of at most 5 minutes, preferably over the course of at most 3 minutes, to a temperature in the region of the crystallization temperature of Ba1-xZ1xTi1-yZ2yO3, whereby Z1 is an element selected from the group consisting of Sr, Ca, Ce, Pb, La and Sm, whereby Z2 is an element selected from the group consisting of Zr, Hf, Nb, V, Y, Sc and Ta, and whereby x and y are each independently of one another 0?x,y?0.5, preferably 0?x,y?0.1, but substantially below the crystallization temperature of Ba[Al2Si2O8].

Abstract: A method of ceramicizing a floated glass is provided where the glass ceramic material obtained thereby has high stability because of the special quality of the atmosphere in the ceramicizing process. The glass ceramics thus obtained have special surface properties that avoid crack formation. Thereby very high bending tensile strengths are achieved. These glass ceramics can be used as fire protection glass, hot plate of a cooker having a coating on the lower side, safety glass, panes of wood-burning fireplace inserts, in colored form as hot plate of a cooker, base plate, thermally resistant panel lining in furnaces and microwave facilities.

Abstract: The process of making the glass-ceramic includes ceramicizing a starting glass at a heating or cooling rate during the ceramicization of at least 10 K/min, so that the glass-ceramic contains at least 50% by volume of ferroelectric crystallites with a maximum diameter of from 20 to 100 nm and not more than 10% by volume of nonferroelectric crystallitesis. The glass ceramic produced by the process contains no pores or not more than 0.01% by volume of the pores and a value of e?·V2max of the glass-ceramic is at least 20 (MV/cm)2, wherein e? is the dielectric constant at 1 kHz and Vmax is the breakdown voltage per unit thickness. The ferroelectric crystallites preferably have a perovskite structure and are composed of substantially pure or doped BaTiO3 and/or BaTi2O5.

Abstract: Laminated, transparent set of panes made of brittle materials and interleaved laminated films, wherein the brittle materials are various glasses, special glasses, glass-ceramics, transparent ceramics and crystalline materials, process for producing and bending the set of panes and films, and its use thereof, as a bulletproof, unbreakable and shockproof glazing with a low weight per unit area.

Abstract: A glass having excellent resistance against surface damages is provided. The glass includes a content of alkaline earth oxides of at least 0.3% by weight and of P2O5 of 0.1 to 4% by weight; the glass has at least one surface that has precipitations with a mean size of 1 to 20 ?m. A method is further provided and includes melting a glass batch, yielding a glass melt, and casting the glass melt onto a float bath. The glass melt is maintained on the float bath at a temperature of above 1000° C. for at least 5 minutes, and yields glass. The glass has a content of alkaline earth oxides of at least 0.3% by weight and of P2O5 of 0.1 to 4% by weight, and the glass has at least one surface that has precipitations with a mean size of 1 to 20 ?m.

Abstract: A method is described for making a float glass convertible into a glass ceramic, by which a largely crystal fault-free glass can be produced. In this method the glass is cooled from a temperature (TKGmax), at which a crystal growth rate is at a maximum value (KGmax), to another temperature (TUEG), at which practically no more crystal growth occurs, with a cooling rate, KR, in ° C. min?1 according to: KR UEG KGmax ? ? ? ? T UEG KGmax 100 · KGmax , wherein ?T=TKGmax?TUEG, and KGmax=maximum crystal growth rate in ?m min?1. The float glass has a thickness below an equilibrium thickness, a net width of at least 1 m and has no more than 50 crystals with a size of more than 50 ?m, especially no crystals with a size of more than 10 ?m, per kilogram of glass within the net width.

Abstract: A method for making a float glass convertible into a glass ceramic, by which a largely crystal fault-free glass can be produced. In this method the glass is cooled from a temperature (TKGmax), at which a crystal growth rate is at a maximum value (KGmax), to another temperature (TUEG), at which practically no more crystal growth occurs, with a cooling rate, KR, in ° C. min?1 according to: KR UEG KG max ? ? ? ? T UEG KG max 100 · KG max , wherein ?T=TKGmax?TUEG, and KGmax=maximum crystal growth rate in ?m min?1. The float glass has a thickness below an equilibrium thickness, a net width of at least 1 m and has no more than 50 crystals with a size of more than 50 ?m, especially no crystals with a size of more than 10 ?m, per kilogram of glass within the net width.

Abstract: A process for the production of a glass-ceramic comprises the following steps: a) providing a mixture comprising at least SiO2, Al2O3, BaO and TiO2, b) melting the mixture in order to produce a glass phase, c) cooling the glass phase, and d) ceramicizing the glass phase. In the process, the glass phase is heated over the course of at most 5 minutes, preferably over the course of at most 3 minutes, to a temperature in the region of the crystallization temperature of Ba1-xZ1xTi1-yZ2yO3, whereby Z1 is an element selected from the group consisting of Sr, Ca, Ce, Pb, La and Sm, whereby Z2 is an element selected from the group consisting of Zr, Hf, Nb, V, Y, Sc and Ta, and whereby x and y are each independently of one another 0?x,y?0.5, preferably 0?x,y?0.1, but substantially below the crystallization temperature of Ba[Al2Si2O8].

Abstract: The process of making the glass-ceramic includes ceramicizing a starting glass at a heating or cooling rate during the ceramicization of at least 10 K/min, so that the glass-ceramic contains at least 50% by volume of ferroelectric crystallites with a maximum diameter of from 20 to 100 nm and not more than 10% by volume of nonferroelectric crystallitesis. The glass ceramic produced by the process contains no pores or not more than 0.01% by volume of the pores and a value of e?·V2max of the glass-ceramic is at least 20 (MV/cm)2, wherein e? is the dielectric constant at 1 kHz and Vmax is the breakdown voltage per unit thickness. The ferroelectric crystallites preferably have a perovskite structure and are composed of substantially pure or doped BaTiO3 and/or BaTi2O5.

Abstract: The method produces a glass-ceramic article substantially in the form of a plate with improved high temperature difference resistance or strength. The glass-ceramic article contains keatite mixed crystals (KMK) or high quartz mixed crystals (HQMK) as well as the keatite mixed crystals (KMK). The method includes heating a glass-ceramic in a high quartz mixed crystal state to form the keatite mixed crystals with a heating rate of 20 K/min to 150 K/min, preferably more than 15 K/min, especially preferably more than 20 K/min. These high heating rates increase the temperature difference resistance.