Heraeus Quarzglas Gmbh & Co Kg

Heraeus Quartz America LLC

Nadine Tscholitsch

Christian Schenk

Gerrit Scheich

Christian Neumann

Ashur J Atanos

Matthew J Donelon

Frank Wessely

Andreas Goetzendorfer

Stephan Moritz

Bernhard Franz

Dirk Michel

Frank Nuernberg

Ursula Klett

Thomas Baier

In a known method for producing a quartz glass component, a crystal formation layer containing a crystallization promoter is produced on a coating surface of a base body of quartz glass. Starting therefrom, to provide a method for producing a quartz glass component of improved thermal strength and long-term stability which displays a comparatively small deformation particularly also in the case of rapid heating-up processes, it is suggested according to one aspect that a porous crystal formation layer containing amorphous SiOparticles is produced with a mean thickness in the range of 0.1 to 5 mm, and that a substance which contains cesium and/or rubidium is used as the crystallization promoter.

Quartz glass component of high thermal stability, semifinished product therefor, and method for producing the same

A diffuser material of synthetically produced, pore-containing quartz glass and a method for the manufacture of a molded body consisting fully or in part thereof. The diffuser material has a chemical purity of at least 99.9% SiO, a cristobalite content of not more than 1%, and a density in the range of 2.0 to 2.18 g/cm. Starting therefrom, to indicate a diffuser material which is improved with respect to diffuse reflectivity with Lambertian behavior over a wide wavelength range, high material homogeneity and UV radiation resistance, the quartz glass has a hydroxyl group content in the range of at least 200 wt. ppm and at least 80% of the pores have a maximum pore dimension of less than 20 &#x3bc;m.

Diffuser material of synthetically produced quartz glass and method for the manufacture of a molded body consisting fully or in part thereof

In one method for producing opaque quartz glass, a green body is produced from a slip containing fine, amorphous SiOparticles and coarse SiOreinforcement bodies and the green body is sintered by way of a sintering treatment into a blank made from the opaque quartz glass. The reinforcement bodies with a specific density Dare here embedded in a SiOmatrix with a specific glass density D. Starting from this, in order to provide a blank of opaque quartz glass that is less susceptible to cracking and illustrates homogeneous transmission even in the case of small wall thicknesses, in one aspect sinterable reinforcement bodies are used, the specific density Dof which prior to the sintering treatment is lower than the specific glass density D, and which due to the sintering treatment reach the specific density Dwhich differs from the specific glass density Dby less than 10%.

Method for producing opaque quartz glass, and blank made from the opaque quartz glass

A method for producing a pore-containing opaque quartz glass includes: (a) producing porous SiOgranulate particles from synthetically produced SiO, (b) thermally densifying the SiOgranulate particles to form partly densified SiOgranulate particles, (c) forming a dispersion from the partly densified SiOgranulate particles, (d) comminuting the partly densified SiOgranulate particles to form a slip containing comminuted SiOgranulate particles, (e) shaping the slip into a shaped body and forming a porous SiOgreen body with a green density rG, and (f) sintering the SiOgreen body into opaque quartz glass. To produce opaque quartz glass that is also suited for the use of spray granulate, during step (b), partly densified SiOgranulate particles are produced with a specific surface BET-(A) between 0.025 and 2.5 m/g, and during step (d), comminuted SiOgranulate particles are produced with a specific surface BET-(B) between 4 and 10 m/g.

Method for producing a pore-containing opaque quartz glass

In a known composite material with a fused silica matrix there are regions of silicon-containing phase embedded. In order to provide a composite material which is suitable for producing components for use in high-temperature processes for heat treatment even when exacting requirements are imposed on impermeability to gas and on purity, it is proposed in accordance with the invention that the composite material be impervious to gas, have a closed porosity of less than 0.5% and a specific density of at least 2.19 g/cm, and at a temperature of 1000&#xb0; C. have a spectral emissivity of at least 0.7 for wavelengths between 2 and 8 &#x3bc;m.

Composite material, heat-absorbing component, and method for producing the composite material

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Hanau, Germany

Nadine Tscholitsch