Schott Ag

Thomas Lifka

Steffen Grün

Olaf Claußen

Uwe Kolberg

Ute Woelfel

Silke Wolff

Karl Mennemann

Ralf Jedamzik

Johann Faderl

André Schrepfer

A method for producing a glass ceramic includes: providing a batch of raw materials; heating the batch of raw materials until a melt is obtained, the batch of raw materials being heated at least in a plurality of sections to a temperature above T3 which corresponds to a viscosity of a molten glass of 10dPa*s; refining the melt, the melt being heated at least in a plurality of sections to a temperature above T2.5 which corresponds to a viscosity of the molten glass of 10dPa*s; obtaining a refined glass which is configured for being ceramized to form a glass ceramic material; and ceramizing a glass which is configured for being ceramized to form the glass ceramic material, at least one of the step of heating until the melt is obtained and the step of refining being performed with heating by way of Hand Ocombustion.

Glass ceramic and method for producing a glass ceramic

A method for melting and/or refining glass, glass ceramic or glass which can be ceramized to form glass ceramic includes: providing a batch of raw materials; heating the batch until a melt of molten glass is obtained, the batch being heated at least in sections to a temperature above T3 which corresponds to a viscosity of the molten glass of 10dPa*s; refining the melt, the melt being heated at least in sections to a temperature above T2.5 which corresponds to a viscosity of the molten glass of 10dPa*s, refining of the melt includes adjusting an oxygen partial pressure p(O) which is reduced by at least 60% relative to an Osaturation in the melt at temperature T3; and obtaining a re-fined glass, a refined glass ceramic or a refined glass which can be ceramized to form glass ceramic.

Glass or glass ceramic as well as method for melting and refining glass or glass ceramic

A glass-ceramic component is provided that has a low average coefficient of thermal expansion (CTE) and a high CTE homogeneity. The use of such a component and a process for producing such a component are also provided.

Highly homogeneous glass-ceramic component

The lead-free and arsenic-free optical glasses have a refractive index of 1.83&#x2266;n&#x2266;1.95 and an Abb&#xe9; number of 24&#x2266;&#x3bd;&#x2266;35, good chemical resistance, excellent crystallization stability and a composition, in wt. % based on oxide content, of SiO, 2-8; BO, 15-22; LaO, 35-42; ZnO, 10-18; TiO, 9-15; ZrO, 3-10; NbO, 4-10; and WO, &#x3e;0.5-3. Besides containing at most 5 wt. % of each of GeO, AgO and BaO and conventional fining agents, they may also contain at most in total 5 wt. % of AlO, MgO, CaO, SrO, POand up to at most in total 5 wt. % of the components F, TaO. The glasses are preferably free of alkali metal oxides, BiO, YO, GdOand/or YbO. Optical elements made from the optical glass are also described.

Optical glass, optical elements made therefrom, method of making the optical elements from the glass, and optical components comprising one or more optical elements

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Mainz-Bretzenheim, Germany

Thomas Lifka