The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 05, 2005
Filed:
May. 10, 2002
Thomas Francis Mcnulty, Ballston Lake, NY (US);
David Charles Pender, Schenectady, NY (US);
Victor Lien-kong Lou, Schenectady, NY (US);
Robert Arthur Giddings, Slingerlands, NY (US);
Frederic Francis Ahlgren, Highland Heights, OH (US);
Thomas Francis McNulty, Ballston Lake, NY (US);
David Charles Pender, Schenectady, NY (US);
Victor Lien-Kong Lou, Schenectady, NY (US);
Robert Arthur Giddings, Slingerlands, NY (US);
Frederic Francis Ahlgren, Highland Heights, OH (US);
General Electric Company, Niskayuna, NY (US);
Abstract
A fused quartz article, such as a muffle tube or crucible, with enhanced creep resistance. The enhanced creep resistance is the result of controlled devitrification of the fused quartz article. Controlled devitrification is achieved by coating the article with a colloidal silica slurry doped with metal cations, such as barium, strontium, and calcium. The metal cations in the slurry promote nucleation and growth of cristobalite crystals into the fused quartz at temperatures in the range from about 1000° C. to about 1600° C. The cristobalite has significantly higher viscosity, and therefore greater creep resistance at elevated temperatures, than fused quartz. Methods for applying a doped coating to a fused quartz article and improving the creep resistance of a fused quartz article are also disclosed.