US4469802A
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Process for producing sintered body of boron nitride
Assignee: National Institute for Materials Science
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Filing: 1982-12-17
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Granted: 1984-09-04
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Expires: 2002-12-17
Abstract
Abstract A process for producing a sintered body of cubic system boron nitride comprises steps of: (a) mixing raw material boron nitride selected from the group consisting of hexagonal system boron nitride, cubic system boron nitride, and a mixture thereof with Me 3 B 2 N 4 (where: Me represents an alkaline earth metal) in an amount of from 0.15 to 3.0 mol %; and (b) treating said mixed material at a temperature of 1350° C. and above under a thermodynamically stabilized pressure condition of the cubic system boron nitride.
Inventors
- 👤 Tadashi Endo
- 👤 Osamu Fukunaga
- 👤 Tadao Sato
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 03:45
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/58; C04B35/583; C04B35/5831
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
90 words
A process for producing a sintered body of cubic system boron nitride which comprises steps of: (a) mixing raw material boron nitride selected from the group consisting of hexagonal system boron nitride, cubic system boron nitride, and a mixture thereof with Me 3 B 2 N 4 (where: Me represents an alkaline earth metal) in an amount of from 0.15 to 3.0 mol %; and (b) treating said mixed material at a temperature of 1350° C. and above under a thermodynamically stabilized pressure condition of the cubic system boron nitride.
Claim 2
Dependent Claim
90 words
A process for producing a sintered body of cubic system boron nitride which comprises steps of: (a) mixing raw material boron nitride selected from the group consisting of hexagonal system boron nitride, cubic system boron nitride, and a mixture thereof with Me 3 B 2 N 4 (where: Me represents an alkaline earth metal) in an amount of from 0.15 to 3.0 mol %; and (b) treating said mixed material at a temperature of 1350° C. and above under a thermodynamically stabilized pressure condition of the cubic system boron nitride.
Claim 3
Dependent Claim
34 words
The process according to claim 1, further comprising of treating the surface of the cubic system boron nitride to reversely transform the same into hexagonal system boron nitride at least in one part thereof.
Claim 4
Dependent Claim
27 words
The process according to claim 1, wherein said mixing ratio of Me 3 B 2 N 4 and boron nitride ranges from 0.15 to 1.8 mol %.
Claim 5
Dependent Claim
44 words
The process according to claim 1, wherein said Me 3 B 2 N 4 is one selected from the group consisting of Mg 3 B 2 N 4 , Ca 3 B 2 N 4 , and Sr 3 B 2 N 4 .
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) | 1987-09-04 | 1988-03-05 | 1988-09-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-09-04 | 1992-03-05 | 1992-09-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-09-04 | 1996-03-05 | 1996-09-04 | $7700.00 | Window Closed / Lapsed |