MANUFACTURING METHOD OF TRANSPARENT ALUMINA TUBE FOR HIGH PRESSURE DISCHARGE LAMP

• Main Authors: NAITOU TAKESHI, OSANAWA HITOSHI
• Format: Patent
• Language: English
• Published: 01.08.1983
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS; ELECTRICITY

PURPOSE:To simplify manufacturing process and improve quality by molding the raw material powder whose primary component is high purity alumina fine powder into tube form, smoothly abrading both ends at a specified velocity speed by means of a diamond grindstone, and baking them. CONSTITUTION:For example, a tube-shaped molding body is obtained by using the alumina fine powder with 0.8mu particle diameter as the primary raw material, adding magnesium oxide and water to it, mixing them by means of a ball milling machine or the like, adding polyvinylalcohol or the like as a binding agent, drying and granulating them, obtaining the powder with the average particle diameter of 70mu, and molding it. Then both ends of this molding body are abraded by selecting the kind of grindstone and setting its peripheral speed to 720-2,400m per minute in accordance with the abrasion conditions and this tube-shaped molding body is baked in hydrogen atmosphere. As a result, in the baking process, an alumina tube without any defects in which a mu crack is fully extinct can be obtained, that is, a high quality alumina tube can be obtained by simplifying the process.