PROCESS FOR PRODUCING MEMBERS, PARTICULARLY TUBES, OF TRANSLUCENT ALUMINA

摘要

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 and 1970.degree.C at a constant translation speed between 3 and 50 millimetres 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.