Patent ID: 9505649
Filing Date: 2016-11-29
CPC Classification: C03B,C03C,Y02P

Claim Text:
1. A method of annealing glass comprising: providing a silica-titania glass article, said silica-titania glass article having a first fictive temperature and a first Tzc; heating said glass article to a first temperature, said first temperature being in the range from 60° C. below said first fictive temperature to 10° C. below said first fictive temperature, said heating excluding exposing said glass article to a temperature greater than said first fictive temperature; cooling said glass article at a first rate from said first temperature to a second temperature, said second temperature being at least 25° C. less than said first temperature; cooling said glass article at a second rate to a third temperature, said third temperature being at least 50° C. less than said second temperature, said second rate exceeding said first rate, said cooling producing a finished silica-titania glass article, said finished silica-titania glass article having a second fictive temperature and a second Tzc, said second fictive temperature differing from said first fictive temperature by less than 10° C., said second Tzc differing from said first Tzc by at least 0.5° C.