US4145224A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for enhancing the crystallization rate of high purity amorphous Si3 N4 powder, powders produced thereby and products therefrom
Assignee: GTE Sylvania Inc
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Filing: 1974-11-22
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Granted: 1979-03-20
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Expires: 1994-11-22
Abstract
Abstract High purity, fine Si 3 N 4 powder produced by the vapor phase reaction of SiCl 4 with NH 3 is amorphous. The crystallization rate of the amorphous powder is enhanced by heating the powder while in intimate contact with a titanium containing material, for example, TiN codeposited with the Si 3 N 4 by the simultaneous reaction of TiCl 4 with NH 3 .
Inventors
- 👤 Emil J. Mehalchick
- 👤 Richard N. Kleiner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 17:02
CPC Classifications
C; C01; C01B; C01B21/00; C01B21/06; C01B21/068; C01B21/0687; C04; C04B; C04B35/00; C04B35/515; C04B35/58; C04B35/584; C04B35/593; C01P; C01P2002/00; C01P2002/02; C01P2006/00; C01P2006/80
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
32 words
Si 3 N 4 powder having particles up to 1.0 microns in size, having a purity of at least 99.9 percent, and characterized by additionally containing at least 0.01 weight percent titanium.
Claim 2
Dependent Claim
32 words
Si 3 N 4 powder having particles up to 1.0 microns in size, having a purity of at least 99.9 percent, and characterized by additionally containing at least 0.01 weight percent titanium.
Claim 3
Dependent Claim
21 words
The powder of claim 1 wherein titanium is present in the amount of from about one half to five weight percent.
Claim 4
Dependent Claim
43 words
A polycrystalline body consisting essentially of Si 3 N 4 having a purity of at least 99.9 percent and a density of at least 60 percent of theoretical density, characterized in that said polycrystalline body additionally contains at least 0.01 weight percent titanium.
Claim 5
Dependent Claim
43 words
A polycrystalline body consisting essentially of Si 3 N 4 having a purity of at least 99.9 percent and a density of at least 60 percent of theoretical density, characterized in that said polycrystalline body additionally contains at least 0.01 weight percent titanium.
Claim 6
Dependent Claim
23 words
Polycrystalline body of claim 3 characterized by the presence of titanium in the amount of from about one half to five weight percent.
References Cited (Backward Citations)
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GB1028977A
Cited
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US3352637A
Cited
FR2003568A1
Cited
GB1199811A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-03-19 | 1982-09-18 | 1983-03-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-03-19 | 1986-09-18 | 1987-03-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-03-19 | 1990-09-18 | 1991-03-20 | $7700.00 | Window Closed / Lapsed |