Molded body of quartz glass and process for the production of a molded body of quartz glass

US5736206A · kind A · utility

Assignee

• HERAEUS QUARZGLAS GMBH & CO. KG · DE

Inventors

• Wolfgang Englisch · Kelkheim, DE
• Stephan Moritz · Niederrodenbach, DE
• Dietmar Hellmann · Gelnhausen, DE

Key dates

• Filing date: May 7, 1996
• Grant date: Apr 7, 1998
• Expiry date: May 7, 2016

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T428/1317
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

Molded bodies of quartz glass have at least one surface area of transparent quartz glass, the exposed surfaces of which are smooth and which have a surface microroughness of less than 8 .mu.m. The base material has a chemical purity of at least 99.9% and a cristobalite content of no more than 1%; is gas-impermeable and opaque; and contains pores. At a wall thickness of 1 mm, the base material has a nearly uniform direct spectral transmission of less than 10% in the wavelength range of .lambda.=190-2,650 nm; and which has a density of at least 2.215 g/cm.sup.3. The transparent surface area is formed from base material by heating it to a temperature above 1,650.degree. C. The thickness of the transparent layer is at least 0.5 mm, and its direct spectral transmission in the wavelength range of .lambda.=6001-2,650 nm is at least 60% for a layer thickness of 1 mm.