METHOD FOR MANUFACTURING OPTICALLY TRANSLUCENT POLYCRYSTALLINE MULLITE BODY AND OPTICALLY TRANSLUCENT MULLITE BODY

摘要

P THIS PROCESS CONSISTS OF MAKING AN INTENSIVE AMORPHOUS POWDER OF MIXED OXIDES CONSISTING OF ABOUT 74 BY WEIGHT AT ABOUT 76.5 BY WEIGHT OF ALO THE REST HAS TO COMPRESS THIS POWDER IN A COMPRESS HAVING A MINIMUM VOLUMIC MASS OF 1.0GCM, CALCINING THE TABLET AT A TEMPERATURE WHICH HAS NO SIGNIFICANT HARMFUL EFFECT ON THE TABLET IN THE OXYGEN OR UNDER A VACUUM FROM 6.66 TO 133.3PA (0.05 TORR AT 1, 0TORR) FOR PRODUCING A GAS-IMPROVABLE TABLET, AND SINKING THIS GAS-IMPROVABLE TABLET IN AN ATMOSPHERE SELECTED AMONG AIR, ARGON, HELIUM, NITROGEN AND THEIR MIXTURES, AT A TEMPERATURE BETWEEN 1700C AND 1850C . / P P APPLICATION TO SPEAKERS FOR ARC TUBES. / P