Accession Number : ADD018025

Title :   Germanate Glass Ceramic.

Descriptive Note : Patent, Filed 23 Dec 94, patented 23 Jan 96,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

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

Report Date : 23 Jan 1996

Pagination or Media Count : 5

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 deg-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.

Descriptors :   *GLASS, *CERAMIC MATERIALS, *PATENTS, *GERMANATES, THERMAL PROPERTIES, PHYSICAL PROPERTIES, COMPOSITE MATERIALS, MELTS, ZINC SULFIDES, CRYSTALS, NUCLEATION, SOLIDS, COOLING, SAPPHIRE, HEATING, NUCLEI, SPINEL

Subject Categories : Ceramics, Refractories and Glass
      Inorganic Chemistry
      Crystallography
      Atomic and Molecular Physics and Spectroscopy
      Thermodynamics

Distribution Statement : APPROVED FOR PUBLIC RELEASE