US4005235A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dense sintered boron carbide containing beryllium carbide
Assignee: General Electric Co
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Filing: 1975-11-17
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Granted: 1977-01-25
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Expires: 1995-11-17
Abstract
Abstract A polycrystalline boron carbide sintered body containing beryllium carbide with a density ranging from 85% to 96% of the theoretical density of boron carbide and having a uniform microstructure of equiaxed grains.
Inventors
- 👤 Svante Prochazka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 10:41
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/56; C04B35/563; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12014; Y10T428/12389; Y10T428/12396; Y10T428/1241; Y10T428/13; Y10T428/131
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
107 words
A polycrystalline sintered body comprised of boron carbide wherein the boron/carbon molar ratio ranges from 3.5 to 4.5 and beryllium carbide in an amount ranging from 0.5% by weight to 3% by weight of said boron carbide, said sintered body having a substantially uniform microstructure composed of substantially equiaxed grains of said boron carbide having a grain size ranging from about 30 microns to about 300 microns with said beryllium carbide distributed substantially uniformly throughout said boron carbide and having a grain size less than 10 microns, said sintered body having a density ranging from 85% to about 96% of the theoretical density for said boron carbide.
Claim 2
Dependent Claim
107 words
A polycrystalline sintered body comprised of boron carbide wherein the boron/carbon molar ratio ranges from 3.5 to 4.5 and beryllium carbide in an amount ranging from 0.5% by weight to 3% by weight of said boron carbide, said sintered body having a substantially uniform microstructure composed of substantially equiaxed grains of said boron carbide having a grain size ranging from about 30 microns to about 300 microns with said beryllium carbide distributed substantially uniformly throughout said boron carbide and having a grain size less than 10 microns, said sintered body having a density ranging from 85% to about 96% of the theoretical density for said boron carbide.
Claim 3
Dependent Claim
25 words
The polycrystalline sintered body of claim 1 wherein the density is at least 90% and wherein substantially all of the residual pores are closed pores.
Claim 4
Dependent Claim
18 words
The polycrystalline sintered body of claim 1 wherein said boron carbide is of stoichiometric B 4 C composition.
Claim 5
Dependent Claim
13 words
The polycrystalline sintered body of claim 1 in the form of a tube.
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) | 1980-01-25 | 1980-07-26 | 1981-01-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-01-25 | 1984-07-26 | 1985-01-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-01-25 | 1988-07-26 | 1989-01-25 | $7700.00 | Window Closed / Lapsed |