US4365022A
Expired / Lapsed
US
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Method for manufacture of high-strength sintered article of substances having β-silicon nitride type crystal structure
Assignee: National Institute of Advanced Industrial Science and Technology
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Filing: 1981-11-02
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Granted: 1982-12-21
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Expires: 2001-11-02
Abstract
Abstract A high-strength sintered article of chemical substances having the beta -silicon nitride type crystal structure is produced by blending 50 to 99.9 weight percent of a beta -silicon nitride and/or beta '-Sialon and 50 to 0.1 weight percent of a mixture, as a sintering aid, consisting of BeO, Ga2O3, and Al2O3 in respective amounts such as to have a Ga2O3/BeO ratio in the range of from 2.8 to 9.4, an Al2O3/BeO ratio in the range of from 0.0 to 2.6, and an Al2O3/Ga2O3 ratio in the range of from 0.0 to 1.1, all ratios being ratios by weight and sintering the resultant blend.
Inventors
- 👤 Hideyo Tabata
- 👤 Yoshitaka Kuwahara
- 👤 Michihide Machida
- 👤 Shyoichi Kume
- 👤 Takeo Iga
- 👤 Kazuo Saitoh
- 👤 Shinji Tomura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 18:41
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/58; C04B35/584; C04B35/593; C04B35/597
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
145 words
A method for the manufacture of a high-strength sintered article of β-silicon nitride composition, which comprises blending 50 to 99.9 wt. % of a composition which, on being burned, acquires the structure of β-silicon nitride composition with 50 to 0.1 wt % of a mixture, as a sintering aid, consisting of BeO, Ga 2 O 3 , and Al 2 O 3 of respective amounts such as to have a Ga 2 O 3 /BeO ratio in the range of from 2.8 to 9.4, an Al 2 O 3 /BeO ratio in the range of from 0.0 to 2.6, and an Al 2 O 3 /Ga 2 O 3 ratio in the range of from 0.0 to 1.1, all ratios being ratios by weight, molding the resultant blend, and sintering the molded blend at a temperature in the range of from 1300° to 1850° C.
Claim 2
Independent Claim
145 words
A method for the manufacture of a high-strength sintered article of β-silicon nitride composition, which comprises blending 50 to 99.9 wt. % of a composition which, on being burned, acquires the structure of β-silicon nitride composition with 50 to 0.1 wt % of a mixture, as a sintering aid, consisting of BeO, Ga 2 O 3 , and Al 2 O 3 of respective amounts such as to have a Ga 2 O 3 /BeO ratio in the range of from 2.8 to 9.4, an Al 2 O 3 /BeO ratio in the range of from 0.0 to 2.6, and an Al 2 O 3 /Ga 2 O 3 ratio in the range of from 0.0 to 1.1, all ratios being ratios by weight, molding the resultant blend, and sintering the molded blend at a temperature in the range of from 1300° to 1850° C.
Claim 3
Dependent Claim
25 words
The method according to claim 1, wherein the composition which, on being burned, acquires the structure of β-silicon nitride is Si 3 N 4 .
Claim 4
Dependent Claim
30 words
The method according to claim 2, wherein the sintering is carried out in one atmosphere selected from the group consisting of air, a weakly oxidative atmosphere, and a non-oxidative atmosphere.
Claim 5
Dependent Claim
83 words
The method according to claim 2, wherein Si 3 N 4 contains as impurity at least one oxide selected from the group consisting of Al 2 O 3 and Fe 2 O 3 and/or at least one compound selected from the group consisting of the compounds which, on being burned, produce Al 2 O 3 and Fe 2 O 3 and the sintering aid contains the corresponding components in amounts less the amounts of said oxides contained in Si 3 N 4 .
Claim 6
Dependent Claim
40 words
The method according to claim 1, wherein the composition which, on being burned, acquires the structure of β-silicon nitride is β'-Sialon represented by the general formula, Si 6-Z Al Z O Z N 8-Z , wherein 0.0 ≦Z≦4.2 is satisfied.
Claim 7
Dependent Claim
76 words
The method according to claim 5, wherein β'-Sialon contains as impurity at least one oxide selected from the group consisting of Al 2 O 3 and Fe 2 O 3 and/or at least one compound selected from the group consisting of the compounds which, on being burned, produce Al 2 O 3 and Fe 2 O 3 and the sintering aid contains the corresponding components in amounts less the amounts of said oxides contained in β'-Sialon.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-12-20 | 1986-06-21 | 1986-12-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-12-20 | 1990-06-21 | 1990-12-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-12-20 | 1994-06-21 | 1994-12-21 | $7700.00 | Window Closed / Lapsed |