US4224073A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Active silicon carbide powder containing a boron component and process for producing the same
Assignee: Nippon Crucible Co Ltd
•
Filing: 1978-08-04
•
Granted: 1980-09-23
•
Expires: 1998-08-04
Abstract
Abstract An active silicon carbide powder containing a boron component, which contains the boron component as boron carbide or as a solid solution thereof in a uniformly dispersed state in an amount of about 0.2 to 10 wt %, calculated as boron carbide and a process for producing the same.
Inventors
- 👤 Tadao Sasaki
- 👤 Takasi Natori
- 👤 Isamu Komaru
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 23:37
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/56; C04B35/565; C01; C01B; C01B32/00; C01B32/90; C01B32/914; C01B32/956; C01B32/963; C01B32/984; C01B32/991; C01P; C01P2002/00; C01P2002/50; C01P2002/52; C01P2002/54; C01P2002/70; C01P2002/77; C01P2004/00; C01P2004/60; C01P2004/61; C01P2006/00; C01P2006/80
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
120 words
A process for producing an active silicon carbide powder containing a boron component, which comprises mixing carbon powder of a particle size of about 20 μm or less, metallic silicon powder and a boron oxide powder as starting materials, so that the molar % of each component in the ternary system of carbon (C), silicon (Si) and boron oxide (B 2 O 3 ) falls within the region defined by the area k, l, m and n in the FIGURE, heating the resulting mixture in an oxidizing atmosphere containing about 0.3 to about 35 volume % of oxygen to induce a spontaneous continuous reaction at a temperature of about 800° to about 1,450° C., said reaction being substantially instantaneously completed.
Claim 2
Dependent Claim
120 words
A process for producing an active silicon carbide powder containing a boron component, which comprises mixing carbon powder of a particle size of about 20 μm or less, metallic silicon powder and a boron oxide powder as starting materials, so that the molar % of each component in the ternary system of carbon (C), silicon (Si) and boron oxide (B 2 O 3 ) falls within the region defined by the area k, l, m and n in the FIGURE, heating the resulting mixture in an oxidizing atmosphere containing about 0.3 to about 35 volume % of oxygen to induce a spontaneous continuous reaction at a temperature of about 800° to about 1,450° C., said reaction being substantially instantaneously completed.
Claim 3
Dependent Claim
30 words
The process of claim 1, wherein the metallic silicon powder has a particle size of about 200 μm and the boron oxide has a particle size of about 500 μm.
Claim 4
Dependent Claim
19 words
The process of claim 1, wherein the active silicon carbide consists of said silicon carbide and said boron component.
References Cited (Backward Citations)
US3853566A
Cited
US3954483A
Cited
US3968194A
Cited
US4133689A
Cited
US4117096A
Cited
US4080415A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-09-23 | 1984-03-24 | 1984-09-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-09-23 | 1988-03-24 | 1988-09-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-09-23 | 1992-03-24 | 1992-09-23 | $7700.00 | Window Closed / Lapsed |