Heraeus Quarzglas Gmbh & Co Kg

Heraeus Quarzglas Gmbh

Rolf Gerhardt

Waltraud Werdecker

Wolfgang Englisch

Jürgen Weber

Juergen Weber

Hartwig Schaper

Werner Ponto

Armin Maul

Thorsten Herbert

Rainer K&ouml;ppler

Wolfgang Krock

Methods for producing a quartz glass component with reflector layer are known in which a reflector layer composed of quartz glass acting as a diffuse reflector is produced on at least part of the surface of a substrate body composed of quartz glass. In order, taking this as a departure point, to specify a method which enables cost-effective and reproducible production of uniform SiOreflector layers on quartz glass components, it is proposed according to the invention that the reflector layer is produced by thermal spraying by means of SiOparticles being fed to an energy carrier, being incipiently melted or melted by means of said energy carrier and being deposited on the substrate body. In the case of a quartz glass component obtained according to the method, the SiOreflector layer is formed as a layer which is produced by thermal spraying and has an opaque effect and which is distinguished by freedom from cracks and uniformity.

Quartz glass component with reflector layer and method for producing the same

In a known method for bonding components made of material with a high silicic acid content by means of a substance to substance bond, a SiO-containing bonding mass is formed between connecting surfaces of the components. In order to provide for cost-efficient manufacture of a thermally stable composite, the invention proposes to generate a SiO-containing bonding mass that is generic with regard to the material with a high silicic acid content, comprising the following procedural steps: provision of a slurry containing amorphous SiOparticles; formation of a slurry mass between the connecting surfaces which are fixed in position with regard to each other; drying of the slurry mass; and solidification of the slurry mass by heating under formation of the SiO-containing bonding mass. A component assembly manufactured according to the method of the invention shows high temperature resistance and thermal fatigue resistance and can also be used in contamination-sensitive applications. The component assembly is characterized by an amorphous SiO-containing bonding mass, whose chemical composition is generic with regard to the material with the high silicic acid content of the basic material of the components, whereby the specific density of the SiO-containing bonding mass is at least 2.0 g/cm.

Method for bonding components made of material with a high silicic acid content

In a process for manufacture of dense, amorphous quartz glass granulate by production of a porous granulate from amorphous SiO powder and vitrification of the granulate, a porous SiO granulate is exposed to a fuel gas flame and is finely dispersed, heated and vitrified therein. The fuel gas flame is more flexible as concerns adjustment of the temperature than in known processes. It is in particular possible to set higher temperatures. The granulate can be exposed to very high sintering temperatures in the fuel gas flame without sintering into agglomerates. At the same time, heat resistance problems of sintering containers such as furnaces and melting pots are avoided. In addition, contamination of the SiO granulate by contact with the walls of sintering or vitrifying containers is eliminated. The process makes it possible to economically produce a highly pure and dense quartz glass granulate.

Process for the manufacture of quartz glass granulate

To produce a free-flowing granulate which has a high bulk density and a defined particle size distribution, which generates little dust, is easy to handle, and is suitable as a starting material for quartz glass products, the mixing operation includes a first mixing phase, in which the materials to be mixed are subjected to a slow mixing action to form a coarse-grained mass, and a second mixing phase, in which the coarse-grained mass is converted to a fine-grained mass by a more intensive mixing action which grinds and compacts the grains. The content of silica powder in the materials to be mixed is adjusted at least during the second mixing phase to a value of at least 75 wt. %.

Process for manufacture of silica granules

Catalyst carrier and method for producing same

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Hammersbach, Germany

Rolf Gerhardt