Method for making polycrystalline alumina arc tubes

摘要

For making tubular polycrystalline alumina arc tubes, the magnesium compound grain-growth inhibitor is added to very finely divided alumina as magnesium aluminate spinel consisting of irregular shaped particles of average diameter less than about 100 nm. The spinel and alumina are thoroughly mixed to achieve a uniform distribution, thereafter isostatically pressed to form a pressed or green tube, with the pressed tube initially being presintered and then final sintered to achieve a density which approximates theoretical.