Accession Number : ADD017418

Title :   Germanate Glass Ceramic.

Descriptive Note : Patent Application, Filed 23 Dec 94,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : Jewell, John M ; Harbison, Barry B ; Aggarwal, Ishwar D

PDF Url : ADD017418

Report Date : 23 Dec 1994

Pagination or Media Count : 17

Abstract : A germanate glass ceramic article which has better thermal and physical properties than the competing materials of zinc sulfide, spinel, and sapphire is made by mixing germanate ceramic glass components; melting the components to form a molten mass; cooling the molten mass to form a solid glass article; nucleating the solid article by heating it in the range of about 630-790 deg C for about 1-16 hours to develop nuclei in the article; and crystallizing the nucleated article by heating it, after nucleation, in the range of about 1/2 minute to about 8 hours to grow the nuclei to crystallites having an average diameter of less then about 1000 nanometer (nm); and cooling to form the glass ceramic. (MM)

Descriptors :   *PATENT APPLICATIONS, *GLASS, *CERAMIC MATERIALS, *INFRARED SPECTRA, *GERMANATES, THERMAL PROPERTIES, TOUGHNESS, NUCLEATION, COOLING, FRACTURE(MECHANICS), MELTING, INFRARED DOMES, HARDNESS, EROSION RESISTANCE, INFRARED WINDOWS

Subject Categories : Ceramics, Refractories and Glass
      Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE