US4766096A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Silicon nitride whisker reinforced glass matrix composites
Assignee: United States Department of the Air Force
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Filing: 1987-02-24
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Granted: 1988-08-23
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Expires: 2007-02-24
Abstract
Abstract An improved composite material consisting of silicon nitride whiskers uniformly dispersed through a glass matrix and a method for making the composite which comprises the step of dispersing the whiskers in a suitable liquid and separating off the fines and, optionally, the step of treating the dispersed whiskers with HF.
Inventors
- 👤 George K. Layden
- 👤 Karl M. Prewo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 21:18
CPC Classifications
C; C03; C03C; C03C14/00; C03C2214/00; C03C2214/06
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
139 words
A method for preparing a composite material which comprises the steps of: (a) dispersing silicon nitride whiskers in a suitable liquid at low shear and separating off the fines; (b) removing the liquid from the remaining silicon nitride whiskers; (c) blending a desired quantity of the whiskers from step (b) with a desired quantity of glass frit and a temporary binder in a suitable liquid to form a mixture; (d) coating a suitable carrier substrate with a layer of said mixture; (e) evaporating the liquid out of said layer; (f) separating the thus-dried layer from said carrier; and (g) stacking a plurality of dried layers in a jig and hot-pressing the layers together at a temperature and pressure sufficient to cause the glass particles to flow to form a void-free matrix throughout which are dispersed said silicon nitride whiskers.
Claim 2
Independent Claim
139 words
A method for preparing a composite material which comprises the steps of: (a) dispersing silicon nitride whiskers in a suitable liquid at low shear and separating off the fines; (b) removing the liquid from the remaining silicon nitride whiskers; (c) blending a desired quantity of the whiskers from step (b) with a desired quantity of glass frit and a temporary binder in a suitable liquid to form a mixture; (d) coating a suitable carrier substrate with a layer of said mixture; (e) evaporating the liquid out of said layer; (f) separating the thus-dried layer from said carrier; and (g) stacking a plurality of dried layers in a jig and hot-pressing the layers together at a temperature and pressure sufficient to cause the glass particles to flow to form a void-free matrix throughout which are dispersed said silicon nitride whiskers.
Claim 3
Dependent Claim
20 words
The method of claim 1 further comprising the step of treating said whiskers dispersed in said liquid with hydrofluoric acid.
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) | 1991-08-23 | 1992-02-22 | 1992-08-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-08-23 | 1996-02-22 | 1996-08-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-08-23 | 2000-02-22 | 2000-08-23 | $7700.00 | Window Closed / Lapsed |