US4142879A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for producing low expansion ceramics
Assignee: GTE Sylvania Inc
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Filing: 1976-12-15
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Granted: 1979-03-06
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Expires: 1996-12-15
Abstract
Abstract Low thermal expansion ceramics of essentially 100 percent cordierite solid solution are prepared by the devitrification of a glass frit compact having the nominal composition in weight percent 16 percent MgO, 30 percent Al 2 O 3 , 54 percent SiO 2 . These ceramics exhibit adequate density and strength and are useful for example in the fabrication of gas turbine engine components such as rotor vanes and heat exchangers.
Inventors
- 👤 Carl W. Fritsch, Jr.
- 👤 Robert W. Wolfe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 21:46
CPC Classifications
C; C03; C03C; C03C10/00; C03C10/0036; C03C10/0045; C04; C04B; C04B35/00; C04B35/01; C04B35/16; C04B35/18; C04B35/195; F; F01; F01D; F01D5/00; F01D5/12; F01D5/28; F01D5/284
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
120 words
Process for producing a ceramic body consisting essentially of cordierite solid solution and having a linear thermal expansion of 600 to 900 ppm over the temperature range 25° C. to 800° C., the process consisting essentially of: (a) forming a glass having a composition consisting essentially of 14 to 18 weight percent MgO, 28 to 32 weight percent Al 2 O 3 , and 52 to 56 weight percent SiO 2 , (b) reducing the glass to finely divided particles, (c) forming the particles into a green compact, and (d) heating the compact at a temperature within the range of 1350° C. to 1425° C. to promote devitrification and sintering of the compact to form a structurally integrated ceramic body.
Claim 2
Dependent Claim
120 words
Process for producing a ceramic body consisting essentially of cordierite solid solution and having a linear thermal expansion of 600 to 900 ppm over the temperature range 25° C. to 800° C., the process consisting essentially of: (a) forming a glass having a composition consisting essentially of 14 to 18 weight percent MgO, 28 to 32 weight percent Al 2 O 3 , and 52 to 56 weight percent SiO 2 , (b) reducing the glass to finely divided particles, (c) forming the particles into a green compact, and (d) heating the compact at a temperature within the range of 1350° C. to 1425° C. to promote devitrification and sintering of the compact to form a structurally integrated ceramic body.
Claim 3
Dependent Claim
41 words
The process of claim 1 wherein a glass is formed having the composition consisting essentially of 15 to 17 weight percent MgO, 29 to 31 weight percent Al 2 O 3 , and 53 to 55 weight percent SiO 2 .
Claim 4
Dependent Claim
76 words
The process of claim 1 in which the glass is formed by mixing oxides or materials which upon heating convert to oxides of Mg, Al, and Si, prereacting the mixture by heating at a temperature of from 800° to 1000° C. for 1 to 4 hours, and melting the prereacted mixture at a temperature within the range of 1490° C. to 1600° C. for from 4 to 24 hours, the longer times corresponding to lower temperatures.
References Cited (Backward Citations)
US3365314A
Cited
US3450546A
Cited
US3490888A
Cited
US3480452A
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US3531307A
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US3940255A
Cited
US4015048A
Cited
US3979216A
Cited
US4042403A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-03-05 | 1982-09-04 | 1983-03-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-03-05 | 1986-09-04 | 1987-03-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-03-05 | 1990-09-04 | 1991-03-06 | $7700.00 | Window Closed / Lapsed |