Glass-ceramic hermetic seals to high thermal expansion metals
Abstract
A process for forming glass-ceramic materials from an alkaline silica-lithia glass composition comprising 60-72 mole-% SiO/sub 2/, 18-27 mole-% Li/sub 2/O, 0-5 mole-% Al/sub 2/O/sub 3/, 0-6 mole-% K/sub 2/O, 0-3 mole-% B/sub 2/O/sub 3/, and 0.5-2.5 mole-% P/sub 2/O/sub 5/, which comprises heating said glass composition at a first temperature within the 950-1050/degree/C range for 5-60 minutes, and then at a devitrification temperature within the 700-900/degree/C range for about 5-300 minutes to obtain a glass-ceramic having a thermal expansion coefficient of up to 210 x 10/sup /minus/7///degree/C. These ceramics form strong, hermetic seals with high expansion metals such as stainless steel alloys. An intermediate nucleation heating step conducted at a temperature within the range of 675-750/degree/C for 10-120 minutes may be employed between the first stage and the devitrification stage. 1 fig., 2 tabs.
- Inventors:
- Issue Date:
- Research Org.:
- EG and G Mound Applied Technologies, Miamisburg, OH (USA)
- OSTI Identifier:
- 6749151
- Patent Number(s):
- -US-A6043526
- Assignee:
- TIC; ERA-14-001157; EDB-88-184938
- DOE Contract Number:
- AC04-76DP00053
- Resource Type:
- Patent
- Resource Relation:
- Other Information: Portions of this document are illegible in microfiche products
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 36 MATERIALS SCIENCE; LITHIUM OXIDES; SEALS; SILICA; CERAMICS; CHEMICAL COMPOSITION; DESIGN; GLASS; HEAT TREATMENTS; THERMAL EXPANSION; ALKALI METAL COMPOUNDS; CHALCOGENIDES; EXPANSION; LITHIUM COMPOUNDS; MINERALS; OXIDE MINERALS; OXIDES; OXYGEN COMPOUNDS; SILICON COMPOUNDS; SILICON OXIDES 360601* -- Other Materials-- Preparation & Manufacture; 360603 -- Materials-- Properties
Citation Formats
Kramer, D.P., and Massey, R.T. Glass-ceramic hermetic seals to high thermal expansion metals. United States: N. p., 1987.
Web.
Kramer, D.P., & Massey, R.T. Glass-ceramic hermetic seals to high thermal expansion metals. United States.
Kramer, D.P., and Massey, R.T. Tue .
"Glass-ceramic hermetic seals to high thermal expansion metals". United States.
@article{osti_6749151,
title = {Glass-ceramic hermetic seals to high thermal expansion metals},
author = {Kramer, D.P. and Massey, R.T.},
abstractNote = {A process for forming glass-ceramic materials from an alkaline silica-lithia glass composition comprising 60-72 mole-% SiO/sub 2/, 18-27 mole-% Li/sub 2/O, 0-5 mole-% Al/sub 2/O/sub 3/, 0-6 mole-% K/sub 2/O, 0-3 mole-% B/sub 2/O/sub 3/, and 0.5-2.5 mole-% P/sub 2/O/sub 5/, which comprises heating said glass composition at a first temperature within the 950-1050/degree/C range for 5-60 minutes, and then at a devitrification temperature within the 700-900/degree/C range for about 5-300 minutes to obtain a glass-ceramic having a thermal expansion coefficient of up to 210 x 10/sup /minus/7///degree/C. These ceramics form strong, hermetic seals with high expansion metals such as stainless steel alloys. An intermediate nucleation heating step conducted at a temperature within the range of 675-750/degree/C for 10-120 minutes may be employed between the first stage and the devitrification stage. 1 fig., 2 tabs.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1987},
month = {4}
}