Method for coating a component for use in a crucible drawing method for quartz glass, and coated component obtained according to the method

US7955715B2 · kind B2 · utility

Assignee

• HERAEUS QUARZGLAS GMBH & CO. KG · DE

Inventors

• Martin Trommer · Bitterfeld-Wolfen, DE
• Rainer Berg · Langenselbold, DE
• Nigel Whippey · Seligenstadt, DE
• Helmut Leber · Hanau, DE
• Joerg Becker · Bad Aibling, DE

Key dates

• Filing date: Dec 20, 2006
• Grant date: Jun 7, 2011
• Expiry date: Mar 4, 2030

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T428/1284
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

In a known method for coating a crucible for use at a high working temperature in a crucible drawing method for quartz glass, a base body wall of tungsten has applied thereto a protective layer containing a coating metal consisting of the group selected from iridium, rhenium, osmium and ruthenium. Starting therefrom, to provide a method for producing such a component exhibiting high corrosion resistance to the quartz glass melt at low material costs, it is suggested according to the invention that the protective layer should be produced from a layer material which contains tungsten and the coating metal, and in which the amount of the coating metal should be dimensioned such that it exceeds the limit amount of a coating metal-rich phase boundary of a solid mixture phase of tungsten and the coating metal, with the solid mixture phase being thermodynamically stable at the working temperature, by not more than 25 at. % (based on the total amount of tungsten and the coating metal in the layer material).