HIGH DELIVERY TEMPERATURE ISOPIPE MATERIALS
Isopipes (13) 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 pO2 of less than 0.1 using less than 10 weight percent of one or more sintering aids...
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Main Author | |
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Format | Patent |
Language | English |
Published |
26.08.2010
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Subjects | |
Online Access | Get full text |
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Summary: | Isopipes (13) 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 pO2 of 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 SiO2 layer (31) which exhibits substantially only a passive oxidation mechanism. The SiO2 layer (31) serves as a protective barrier for further oxidation of the silicon nitride during use of the isopipe (13). The isopipes (13) exhibit less sag during use than isopipes composed of zircon. |
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Bibliography: | Application Number: US20090391750 |