POLYCRYSTALLINE ALUMINA MATERIAL

摘要

LD 7426 Increased optical transmission is provided for a body of light-transmissive polycrystalline alumina. The body of alumina has relatively uniform size equiaxed grains of alumina, and is essentially free of porosity and secondary phase material. A tube of the improved optical material can be used as the light-transmissive envelope for high-intensity discharge lamps, especially sodium vapor lamps and other metal-vapor lamps. Such lamps exhibit increased light output as a result of the increased optical transmission. A method of producing the imnproved optical material is also disclosed.