Accession Number : AD0910282

Title :   High-Quality Sapphire Envelopes for Alkali-Metal Vapor Lamps.

Descriptive Note : Final technical rept. May 72-Jan 73,

Corporate Author : UNION CARBIDE CORP SAN DIEGO CA CRYSTAL PRODUCTS DEPT

Personal Author(s) : King, G. B. ; Otten, P. E.

Report Date : MAY 1973

Pagination or Media Count : 47

Abstract : The surface finish of single crystal sapphire tube envelopes for use with alkali metal vapor lamps was improved by optimizing fabrication and annealing procedures. The Fabrication technique developed consists essentially of using large diameter Czochralski white or clear sapphire so oriented that its optic axis is inclined at 90 deg to the growth axis and core drilling tube blanks such that the optic axis (c-axis) is coincident with the tube axis. Core drilling of the bore of the tube is followed by a series of reaming, high-temperature vacuum annealing, and lapping process steps to achieve final surface finish of approximately 0.6 microinch CLA on the bore surface. The outside surface is finished with generally standard O.D. polishing techniques including O.D. grinding and roll polishing. Tubes produced in this contract were 5mm I.D. by 7mm O.D. by 50mm length. (Author)

Descriptors :   (*LIGHTING EQUIPMENT, ALKALI METALS), (*SAPPHIRE, MANUFACTURING), VAPORS, SYNTHETIC STONES, CRYSTAL GROWTH, PACKAGING, ANNEALING, DRILLING, DRILLS, SURFACE PROPERTIES, FINISHES, REAMERS, DIAMONDS, BRUSHES, CHEMICAL MILLING, ETCHING, PILOT PLANTS.

Subject Categories : Fabrication Metallurgy
      Air Condition, Heating, Lighting & Ventilating

Distribution Statement : APPROVED FOR PUBLIC RELEASE