Abstract:
Moulded bodies made of quartz glass with at least one surface region of tranparent quartz glass, whose free surfaces are smooth and which have a superficial microroughness of less than 8 mu m, are already known. To facilitate production of such a body having a simple structure, cost-effectively and without the need for the stocking or separate production of auxiliary components, it will consist of a core body, the base material of which is at least 99.9 % chemically pure and has a cristobalite content of no more than 1 %; is impermeable to gases, opaque, and porous, has a virtually constant direct spectral transmission in the wavelength range lambda = 190 nm - lambda = 2.650 nm of below 10 % for 1 mm of thickness, and has a density of at least 2.15 g/cm . The transparent surface region is formed from the base material which is heat treated at a temperature in excess of 1.650 DEG C, is at least 0.5 mm thick and has a direct spectral transmission of at least 60 % in the wavelength range lambda = 600 nm - lambda = 2.650 nm for 1 mm of thickness. The invention also relates to process for manufacturing a moulded body of this type from quartz glass.
Abstract:
The present invention is to provide a synthetic quartz glass body having a high light transmittance. The present invention provides a synthetic quartz glass body having pores in a surface part thereof.
Abstract:
To provide opaque quartz glass having no water absorbing properties and being excellent in infrared light shielding properties, and a method for its production. In the production of opaque quartz glass of the present invention, a fine amorphous silica powder and a pore forming agent are mixed, then molded and heated at a predetermined temperature, to obtain opaque quartz glass wherein contained pores are closed pores, the average pore size of pores is from 5 to 20 μm, and the content density of pores is high, whereby the heat shielding properties are high.
Abstract:
A method for producing a quartz glass body from a get body is provided, wherein the gel body generated from a colloidal suspension is at least formed and compressed into the quartz glass body Displacement bodies are added to the colloidal suspension prior to gelating into the gel body, and are completely removed from the gel body after gelating, wherein hollow spaces are generated at the positions of the removed displacement bodies, so that a translucent or opaque quartz glass body is generated. Further, a gel body for producing a quartz glass body is provided, wherein displacement bodies are introduced into the gel body that can be completely removed from the gel body, so that hollow spaces arise at the positions of the displacement bodies. A quartz glass body is also provided that includes vacuoles or hollow spaces filled with gas.
Abstract:
In order to provide a vitreous silica crucible which does not employ a crystallization accelerator but is difficult to deform during its use even under high temperature, and is easily manufactured, there is provided a vitreous silica crucible for pulling single-crystal silicon wherein the outer surface layer is formed of a bubble-containing vitreous silica layer, the inner surface layer is formed of a vitreous silica layer whose bubbles are invisible to the naked eye, a surface of the outer surface layer includes an unmelted or half-melted silica layer (abbreviated as a half-melted silica layer), and the center line average roughness (Ra) of the half-melted silica layer is 50 to 200 μm, also preferably, and the thickness of the half-melted silica layer is 0.5 to 2.0 mm.