Chemically polished polycrystalline alumina material

摘要

Increased optical transmission is provided for a body of light transmissive polycrystalline alumina body treated at elevated temperatures with a molten flux composition. A tube of the flux polished material which can be used as the light transmissive envelope for high intensity discharge lamps especially sodium vapor lamps, improves light output from the lamp as the result of increased in-line transmission for the treated envelope member. A method of chemically polishing polycrystalline alumina material in this manner is also disclosed.