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Title: Method of processing "BPS" glass ceramic and seals made therewith

Abstract

A glass ceramic composition, a glass ceramic-to-metal seal, and more specifically a hermetic glass ceramic-to-metal seal prepared by subjecting a glass composition comprising, by weight percent, SiO.sub.2 (65-80%), LiO.sub.2 (8-16%), Al.sub.2 O.sub.3 (2-8%), K.sub.2 O (1-8%), P.sub.2 O.sub.5 (1-5%), B.sub.2 O.sub.3 (0.5-7%), and ZnO (0-5%) to the following processing steps: 1) heating the glass composition in a belt furnace to a temperature sufficient to melt the glass and crystallize lithium phosphate, 2) holding at a temperature and for a time sufficient to create cristobalite nuclei, 3) cooling at a controlled rate and to a temperature to cause crystallization of lithium silicates and growth of cristobalite, and 4) still further cooling in stages to ambient temperature. This process produces a glass ceramic whose high coefficient of thermal expansion (up to 200.times.10.sup.-7 in/in/.degree.C.) permits the fabrication of glass ceramic-to-metal seals, and particularly hermetic glass ceramic seals to nickel-based and stainless steel alloys and copper.

Inventors:
 [1];  [1];  [1]
  1. Albuquerque, NM
Publication Date:
Research Org.:
AT&T
OSTI Identifier:
871891
Patent Number(s):
US 5820989
Assignee:
Sandia Corporation (Albuquerque, NM)
DOE Contract Number:  
AC04-76DP00789
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
method; processing; bps; glass; ceramic; seals; therewith; composition; ceramic-to-metal; seal; specifically; hermetic; prepared; subjecting; comprising; weight; percent; sio; 65-80; lio; 8-16; 2-8; 1-8; 1-5; 5-7; zno; 0-5; following; steps; heating; belt; furnace; temperature; sufficient; melt; crystallize; lithium; phosphate; holding; time; create; cristobalite; nuclei; cooling; controlled; rate; crystallization; silicates; growth; stages; ambient; process; produces; coefficient; thermal; expansion; 200; times; 10; -7; degree; permits; fabrication; particularly; nickel-based; stainless; steel; alloys; copper; steel alloy; ceramic seals; controlled rate; glass ceramic; ceramic composition; composition comprising; time sufficient; thermal expansion; weight percent; stainless steel; ambient temperature; temperature sufficient; glass composition; processing steps; process produces; steel alloys; metal seal; processing step; ceramic-to-metal seal; glass ceramic-to-metal; hermetic glass; metal seals; ceramic seal; /428/

Citation Formats

Reed, Scott T, Stone, Ronald G, McCollister, Howard L, and Wengert, deceased, Paul R. Method of processing "BPS" glass ceramic and seals made therewith. United States: N. p., 1998. Web.
Reed, Scott T, Stone, Ronald G, McCollister, Howard L, & Wengert, deceased, Paul R. Method of processing "BPS" glass ceramic and seals made therewith. United States.
Reed, Scott T, Stone, Ronald G, McCollister, Howard L, and Wengert, deceased, Paul R. 1998. "Method of processing "BPS" glass ceramic and seals made therewith". United States. https://www.osti.gov/servlets/purl/871891.
@article{osti_871891,
title = {Method of processing "BPS" glass ceramic and seals made therewith},
author = {Reed, Scott T and Stone, Ronald G and McCollister, Howard L and Wengert, deceased, Paul R.},
abstractNote = {A glass ceramic composition, a glass ceramic-to-metal seal, and more specifically a hermetic glass ceramic-to-metal seal prepared by subjecting a glass composition comprising, by weight percent, SiO.sub.2 (65-80%), LiO.sub.2 (8-16%), Al.sub.2 O.sub.3 (2-8%), K.sub.2 O (1-8%), P.sub.2 O.sub.5 (1-5%), B.sub.2 O.sub.3 (0.5-7%), and ZnO (0-5%) to the following processing steps: 1) heating the glass composition in a belt furnace to a temperature sufficient to melt the glass and crystallize lithium phosphate, 2) holding at a temperature and for a time sufficient to create cristobalite nuclei, 3) cooling at a controlled rate and to a temperature to cause crystallization of lithium silicates and growth of cristobalite, and 4) still further cooling in stages to ambient temperature. This process produces a glass ceramic whose high coefficient of thermal expansion (up to 200.times.10.sup.-7 in/in/.degree.C.) permits the fabrication of glass ceramic-to-metal seals, and particularly hermetic glass ceramic seals to nickel-based and stainless steel alloys and copper.},
doi = {},
url = {https://www.osti.gov/biblio/871891}, journal = {},
number = ,
volume = ,
place = {United States},
year = {Thu Jan 01 00:00:00 EST 1998},
month = {Thu Jan 01 00:00:00 EST 1998}
}