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AssigneeSociete Europeenne des Ceramiques A lumineuses "EUROCERAL"
InventorsRene Clement, Francis Gugliermotte
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A process for producing fritted alumina members having a high optical transparency and a high mechanical strength of the type involving the production of the members from a high purity alumina powder to which has been added an organic binder and a small percentage of oxide, particularly of magnesium and/or rare earth, followed by the shaping thereof and subjecting them to two successive heat treatments, namely a first treatment in an oxidizing atmosphere to remove the binder and consolidate the particles and a second treatment at a higher temperature and in a hydrogen-rich atmosphere for obtaining fritting, wherein the second heat treatment takes place by continuously passing the said members through a kiln kept at a temperature between 1820.degree. and 1970.degree. C. at a constant translation speed between 3 and 50 millimeters per minute, the total time necessary for firing a member from the consolidated or slightly warm state up till its return to ambient temperature varying from approximately 30 minutes to a maximum of 5 hours.
A process for producing fritted alumina members having a high optical transparency and a high mechanical strength from a high purity alumina powder to which has been added an organic binder and a small percentage of oxide, particularly of magnesium and/or rare earth, followed by the shaping thereof and subjecting them to two successive heat treatments, namely a first treatment in an oxidizing atmosphere to remove the binder and consolidate the particles and a second treatment at a higher temperature and in a hydrogen-rich atmosphere for obtaining fritting, wherein the second heat treatment takes place by continuously passing the said members at a constant translation speed between 3 and 50 millimeters per minute through a kiln kept at a temperature between 1820.degree. and 1970.degree. C. and having a heat gradient therein, the total time necessary for firing a member from the consolidated or slightly warm state up till its return to ambient temperature varying from approximately 30 minutes to a maximum of 5 hours.
Dependencies are inferred from the claim text.