Accession Number:

ADD014712

Title:

Low Temperature Synthesis of High Purity Monoclinic Celsian Using Topaz.

Descriptive Note:

Patent Application, Filed 7 Sep 90,

Corporate Author:

DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s):

• Talmy, Inna G.
• Haught, Deborah A.

Report Date:

1990-09-07

Pagination or Media Count:

10.0

Abstract:

This invention relates to ceramics and more particularly to aluminosilicate ceramics. Ceramics based on monoclinic celsian BaO-A12O3-2Si02 can be considered for applications requiring materials with a combination of high melting point, low thermal expansion, high thermal shock resistance, high-frequency working capabilities, low and thermally stable dielectric constant and low loss tangent. A process for preparing monoclinic celsian from topaz and BaCO3, powders by heating an intimate mixture of the powders at a temperature of from 900 degree C to less then 1590 degree C in an atmosphere of the gases generated by the monoclinic celsian formation reaction itself. ttl

Descriptors:

• *CERAMIC MATERIALS
• *ALUMINUM COMPOUNDS
• *SILICATES
• PATENT APPLICATIONS
• ATMOSPHERES
• GASES
• HEATING
• HIGH FREQUENCY
• HIGH RATE
• HIGH TEMPERATURE
• LOW LOSS
• LOW TEMPERATURE
• MELTING POINT
• MIXTURES
• POWDERS
• PURITY
• RESPONSE
• SHOCK RESISTANCE
• SYNTHESIS
• TANGENTS
• THERMAL EXPANSION
• THERMAL RESISTANCE

Subject Categories:

• Industrial Chemistry and Chemical Processing
• Ceramics, Refractories and Glass

Distribution Statement:

APPROVED FOR PUBLIC RELEASE