Patent US4407971A successfully refreshed from Google Patents.
US4407971A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sintered body of silicon nitride-based ceramics
Assignee: Toshiba Corp
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Filing: 1982-08-26
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Granted: 1983-10-04
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Expires: 2002-08-26
Abstract
Abstract There are disclosed a sintered body of ceramics, comprising 0.1 to 10% by weight of yttrium oxide; 0.1 to 10% by weight of aluminum oxide; 0.1 to 10% by weight of aluminum nitride; 0.1 to 5% by weight of at least one silicide selected from the group consisting of magnesium silicide, calcium silicide, titanium silicide, vanadium silicide, chromium silicide, manganese silicide, zirconium silicide, niobium silicide, molybdenum silicide, tantalum silicide and tungsten silicide; and the balance being silicon nitride, and a process for producing a sintered body of ceramics, which comprises molding a powder mixture of the same composition, and sintering the resultant molded compact in a non-oxidative atmosphere. According to the present invention, it is possible to manufacture sintered body having high density and excellent impact resistance.
Inventors
- 👤 Michiyasu Komatsu
- 👤 Akihiko Tsuge
- 👤 Hiroyasu Ohta
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 13:11
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/58; C04B35/584; C04B35/593
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
132 words
A sintered body of ceramics having high density, high flexural strength, and high impact resistance, comprising 0.1 to 10% by weight of yttrium oxide (Y 2 O 3 ); 0.1 to 10% by weight of aluminum oxide (Al 2 O 3 ); 0.1 to 10% by weight of aluminum nitride (AlN); 0.1 to 5% by weight of at least one silicide selected from the group consisting of magnesium silicide (Mg 2 Si), calcium silicide (CaSi 2 ), titanium silicide (TiSi 2 ), vanadium silicide (VSi 2 ), chromium silicide (CrSi 2 ), manganese silicide (MnSi), zirconium silicide (ZrSi 2 ), niobium silicide (NbSi 2 ), molybdenum silicide (MoSi 2 ), tantalum silicide (TaSi 2 ), and tungsten silicide (WSi 2 ); and the balance being silicon nitride (Si 3 N 4 ).
Claim 2
Dependent Claim
132 words
A sintered body of ceramics having high density, high flexural strength, and high impact resistance, comprising 0.1 to 10% by weight of yttrium oxide (Y 2 O 3 ); 0.1 to 10% by weight of aluminum oxide (Al 2 O 3 ); 0.1 to 10% by weight of aluminum nitride (AlN); 0.1 to 5% by weight of at least one silicide selected from the group consisting of magnesium silicide (Mg 2 Si), calcium silicide (CaSi 2 ), titanium silicide (TiSi 2 ), vanadium silicide (VSi 2 ), chromium silicide (CrSi 2 ), manganese silicide (MnSi), zirconium silicide (ZrSi 2 ), niobium silicide (NbSi 2 ), molybdenum silicide (MoSi 2 ), tantalum silicide (TaSi 2 ), and tungsten silicide (WSi 2 ); and the balance being silicon nitride (Si 3 N 4 ).
Claim 3
Dependent Claim
83 words
A sintered body of ceramics according to claim 1, wherein said sintered body comprises 0.5 to 8% by weight of yttrium oxide; 0.5 to 8% by weight of aluminum oxide; 0.5 to 8% by weight of aluminum nitride; 0.25 to 3% by weight of at least one silicide selected from the group consisting of magnesium silicide, calcium silicide, titanium silicide, vanadium silicide, chromium silicide, manganese silicide, zirconium silicide, niobium silicide, molybdenum silicide, tantalum silicide and tungsten silicide; and the balance being silicon nitride.
Claim 4
Dependent Claim
162 words
A sintered body of ceramics according to claim 1, produced by the process comprising the steps of molding a powder mixture comprising 0.1 to 10% by weight of yttrium oxide (Y 2 O 3 ) powders; 0.1 to 10% by weight of aluminum oxide (Al 2 O 3 ) powders; 0.1 to 10% by weight of aluminum nitride (AlN) powders; 0.1 to 5% by weight of at least one powdery silicide selected from the group consisting of magnesium silicide (Mg 2 Si), calcium silicide (CaSi 2 ), titanium silicide (TiSi 2 ), vanadium silicide (VSi 2 ), chromium silicide (CrSi 2 ), manganese silicide (MnSi), zirconium silicide (ZrSi 2 ), niobium silicide (NbSi 2 ), molybdenum silicide (MoSi 2 ), tantalum silicide (TaSi 2 ), and tungsten silicide (WSi 2 ); and the balance being silicon nitride (Si 3 N 4 ) powders; and sintering the resultant compact in a non-oxidative atmosphere at a temperature between about 1500° C. and 1900° C.
Claim 5
Dependent Claim
115 words
A sintered body of ceramics according to claim 2, produced by the process comprising the steps of molding a powder mixture comprising 0.5 to 8% by weight of yttrium oxide powders; 0.5 to 8% by weight of aluminum oxide powders; 0.5 to 8% by weight of aluminum nitride powders; 0.25 to 3% by weight of at least one powdery silicide selected from the group consisting of magnesium silicide, calcium silicide, titanium silicide, vanadium silicide, chromium silicide, manganese silicide, zirconium silicide, niobium silicide, molybdenum silicide, tantalum silicide, and tungsten silicide; and the balance being silicon nitride powders; and sintering the resultant compact in a non-oxidative atmosphere at a temperature between about 1500° C. and 1900° C.
Claim 6
Dependent Claim
23 words
A sintered body of ceramics according to claim 1, wherein the silicon nitride comprises at least about 70% by weight of the ceramic.
Claim 7
Dependent Claim
24 words
A sintered body of ceramics according to claim 1, wherein the silicon nitride comprises between about 80 and 90% by weight of the ceramic.
Claim 8
Dependent Claim
21 words
A sintered body of ceramics according to claim 1, wherein the silicon nitride comprises a major proportion of alpha-phase silicon nitride.
Claim 9
Dependent Claim
28 words
A sintered body of ceramics according to claim 1, wherein the combined content of the yttrium oxide and aluminum oxide is between about 3 and 15% by weight.
Claim 10
Dependent Claim
28 words
A sintered body of ceramics according to claim 1, wherein the combined content of the yttrium oxide and aluminum oxide is between about 4 and 10% by weight.
Claim 11
Dependent Claim
46 words
A sintered body of ceramics according to claim 1, having a relative density of at least about 95% relative to the theoretical density, a flexural strength of at least about 85 kg/cm 2 and an impact resistance in terms of ΔT of at least 700° C.
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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) | 1986-10-03 | 1987-04-04 | 1987-10-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-10-03 | 1991-04-04 | 1991-10-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-10-03 | 1995-04-04 | 1995-10-04 | $7700.00 | Window Closed / Lapsed |