US4609633A
Expired / Lapsed
US
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Silicon nitride sintered body and method for preparing the same
Assignee: Tungaloy Corp
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Filing: 1984-04-20
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Granted: 1986-09-02
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Expires: 2004-04-20
Abstract
Abstract There is disclosed a silicon nitride body consisting essentially of (A) 0.5 to 25% by weight of at least one of oxides, nitrides and oxynitrides of rare earth elements consisting of Sc, Y and lanthanide elements; (B) 0.5 to 25% by weight of at least one of the nitrides and oxynitrides of elements consisting of Be, Mg, Ca, Sr, Ba and Ra in group IIa and/or of nitrides and oxynitrides of elements consisting of B, Al, Ga, In and Tl in group IIIb of the periodic table; and (C) a remainder including Si 3 N 4 and inevitable impurities. The silicon nitride sintered body of this invention has excellent wear resistance and toughness, and is suitable for an industrial production of materials for heat resistant structures.
Inventors
- 👤 Mikio Fukuhara
- 👤 Yoshitaka Maekawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 19:26
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/58; C04B35/584; C04B35/593
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
95 words
A silicon nitride sintered body consisting essentially of: (A) 0.5 to 25% by weight of at least one from the group consisting of a nitride and an oxynitride of a rare earth element selected from the group consisting of scandium, yttrium and lanthanide elements; (B) 0.5 to 25% by weight of at least oen nitride of an element selected from the group consisting of beryllium, magnesium, calcium, strontium, barium and radium and/or at least one nitride of an element selected from the group consisting of boron, aluminum, gallium, indium and thallium; and (C) silicon nitride.
Claim 2
Dependent Claim
95 words
A silicon nitride sintered body consisting essentially of: (A) 0.5 to 25% by weight of at least one from the group consisting of a nitride and an oxynitride of a rare earth element selected from the group consisting of scandium, yttrium and lanthanide elements; (B) 0.5 to 25% by weight of at least oen nitride of an element selected from the group consisting of beryllium, magnesium, calcium, strontium, barium and radium and/or at least one nitride of an element selected from the group consisting of boron, aluminum, gallium, indium and thallium; and (C) silicon nitride.
Claim 3
Dependent Claim
32 words
The silicon nitride sintered body according to claim 1, wherein said component (B) is at least one nitride of an element from the group consisting of B, Al, Ga, In and Tl.
Claim 4
Dependent Claim
33 words
The silicon nitride sintered body according to claim 1, wherein said component (B) is at least one nitride of an element from the group consisting of Be, Mg, Ca, Sr, Ba and Ra.
Claim 5
Dependent Claim
40 words
A silicon nitride sintered body according to claim 1, consisting of said components (A) and (C) and 0.5 to 25% by weight of at least one nitride of an element from the group of B, Al, Ga, In and Tl.
Claim 6
Dependent Claim
41 words
A silicon nitride sintered body according to claim 1, consisting of said components (A) and (C) and 0.5 to 25% by weight of at least one nitride of an element from the group of Be, Mg, Ca, Sr, Ba and Ra.
Claim 7
Independent Claim
139 words
A method for preparing a silicon nitride sintered body, which comprises the steps of: (A) obtaining a powder compact or a molded product from a mixed powder consisting essentially (i) 0.5 to 25% by weight of at least one from the group consisting of a nitride and an oxynitride of a rare earth element selected from the group consisting of scandium, yttrium and lanthanide elements, (ii) 0.5 to 25% by weight of at least one nitride or an element selected from the group consisting of beryllium, magnesium, calcium, storntium, barium and radium and/or at least one nitride of an element selected from the group consisting of boron, aluminum, gallium, indium and thallium, and (iii) silicon nitride; and (B) thermally sintering said powder compact or said molded product at a temperature of 1500° or 1900° C. in a non-oxidizing atmosphere.
Claim 8
Independent Claim
139 words
A method for preparing a silicon nitride sintered body, which comprises the steps of: (A) obtaining a powder compact or a molded product from a mixed powder consisting essentially (i) 0.5 to 25% by weight of at least one from the group consisting of a nitride and an oxynitride of a rare earth element selected from the group consisting of scandium, yttrium and lanthanide elements, (ii) 0.5 to 25% by weight of at least one nitride or an element selected from the group consisting of beryllium, magnesium, calcium, storntium, barium and radium and/or at least one nitride of an element selected from the group consisting of boron, aluminum, gallium, indium and thallium, and (iii) silicon nitride; and (B) thermally sintering said powder compact or said molded product at a temperature of 1500° or 1900° C. in a non-oxidizing atmosphere.
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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) | 1989-09-01 | 1990-03-03 | 1990-09-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-09-01 | 1994-03-03 | 1994-09-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-09-01 | 1998-03-03 | 1998-09-02 | $7700.00 | Window Closed / Lapsed |