US4101616A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing Si3 N4 article
Assignee: GTE Sylvania Inc
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Filing: 1977-03-23
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Granted: 1978-07-18
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Expires: 1997-03-23
Abstract
Abstract Si 3 N 4 fibrous articles are produced by forming a low density compact of amorphous Si 3 N 4 powder and heat treating the compact to promote in-situ formation of fibrous crystalline alpha Si 3 N 4 . Such articles are useful as thermal insulants, packing materials, resilient seals, etc.
Inventors
- 👤 Sergei-Tomislav Buljan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:45
CPC Classifications
C; C04; C04B; C04B30/00; C04B30/02; C04B35/00; C04B35/515; C04B35/58; C04B35/584; Y; Y10; Y10S; Y10S264/00; Y10S264/19
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
95 words
Process for producing self-supporting fibrous articles consisting essentially of alpha Si 3 N 4 comprising: (a) forming a green body of low bulk density within the range of about 0.1 g/cm 3 to 0.8 g/cm 3 of substantially amorphous Si 3 N 4 powder, and (b) heat treating the body at a temperature within the range of about 1550° C to 1750° C for from about 0.25 to 5 hours in a non-oxidizing atmosphere to promote in situ formation of fibrous crystalline alpha Si 3 N 4 from the amorphous Si 3 N 4 particles.
Claim 2
Dependent Claim
95 words
Process for producing self-supporting fibrous articles consisting essentially of alpha Si 3 N 4 comprising: (a) forming a green body of low bulk density within the range of about 0.1 g/cm 3 to 0.8 g/cm 3 of substantially amorphous Si 3 N 4 powder, and (b) heat treating the body at a temperature within the range of about 1550° C to 1750° C for from about 0.25 to 5 hours in a non-oxidizing atmosphere to promote in situ formation of fibrous crystalline alpha Si 3 N 4 from the amorphous Si 3 N 4 particles.
Claim 3
Dependent Claim
19 words
Process of claim 1 in which the green body is formed by pressing the powder to a green compact.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-07-17 | 1982-01-16 | 1982-07-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-07-17 | 1986-01-16 | 1986-07-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-07-17 | 1990-01-16 | 1990-07-18 | $7700.00 | Window Closed / Lapsed |