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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 {minus}7} in/in/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. 5 figs.

Inventors:
; ; ;
Issue Date:
Research Org.:
AT&T
Sponsoring Org.:
USDOE, Washington, DC (United States)
OSTI Identifier:
675866
Patent Number(s):
5820989
Application Number:
PAN: 8-706,852
Assignee:
Sandia Corp., Albuquerque, NM (United States)
DOE Contract Number:  
AC04-76DP00789
Resource Type:
Patent
Resource Relation:
Other Information: PBD: 13 Oct 1998
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; GLASS; CERAMICS; SEALS; CHEMICAL COMPOSITION; THERMAL EXPANSION; NICKEL BASE ALLOYS; STAINLESS STEELS; COPPER

Citation Formats

Reed, S T, Stone, R G, McCollister, H L, and Wengert, P R. Method of processing ``BPS`` glass ceramic and seals made therewith. United States: N. p., 1998. Web.
Reed, S T, Stone, R G, McCollister, H L, & Wengert, P R. Method of processing ``BPS`` glass ceramic and seals made therewith. United States.
Reed, S T, Stone, R G, McCollister, H L, and Wengert, P R. Tue . "Method of processing ``BPS`` glass ceramic and seals made therewith". United States.
@article{osti_675866,
title = {Method of processing ``BPS`` glass ceramic and seals made therewith},
author = {Reed, S T and Stone, R G and McCollister, H L and Wengert, P 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 {minus}7} in/in/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. 5 figs.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1998},
month = {10}
}