Corning Incorporated

Joseph James McIntosh

Thomas Dale Ketcham

Steven Michael Milillo

Eunyoung Park

Ralph Alfred Langensiepen

Tracey Lynn Timmons

Tracey L Timmons

A ceramic block consisting essentially of substantially homogeneous (YO)PO, where 0.95&#x2266;x&#x2266;1.05, having length LL, a width WW and a height HH, and a volume W of at least 8&#xd7;10messentially free of cracks throughout the volume, a density of at least 85% of the theoretical maximal density of Y0.POunder standard conditions, and a creep rate CR at 1250&#xb0; C. and 6.89 MPa; where CR&#x2266;8.0&#xd7;10hourand method for making the same. The method utilizes a dry process where the starting YP0-based ceramic material is synthesized by reacting anhydrous POwith dry YOpowder.

Large xenotime ceramic block and dry process for making the same

Isopipes () for making a glass or a glass-ceramic using a fusion process are provided. The isopipes are made from an alumina material which has a higher static fatigue than existing alumina materials intended for use as isopipes. In particular, the alumina materials have times-to-failure (static fatigues) of greater than one hour at 1200&#xb0; C. at an applied stress of 10,000 psi. These high levels of static fatigue allow alumina isopipes to replace zircon isopipes in the manufacture of high performance glass sheets by the fusion process, including glass sheets which are incompatible with zircon isopipes but compatible with alumina isopipes, e.g., chip and scratch resistant glass sheets which have high alkali contents.

High static fatigue alumina isopipes

Isopipes () for making a glass or a glass-ceramic using a fusion process are provided. The isopipes are made from a silicon nitride refractory material that is: (a) produced in block form in an atmosphere having a pOof less than 0.1 using less than 10 weight percent of one or more sintering aids, (b) machined into an isopipe configuration, and (c) exposed to a partial pressure of oxygen equal to or greater than 0.1 for a period of time and at a temperature sufficient to form a SiOlayer () which exhibits substantially only a passive oxidation mechanism. The SiOlayer () serves as a protective barrier for further oxidation of the silicon nitride during use of the isopipe (). The isopipes () exhibit less sag during use than isopipes composed of zircon.

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Painted Post, NY, United States of America

Joseph James McIntosh