US4719187A
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US
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Dense sintered bodies of nitride materials
Assignee: Corning Glass Works
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Filing: 1986-12-03
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Granted: 1988-01-12
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Expires: 2006-12-03
Abstract
Abstract This invention is directed to the production of nitride-based ceramic bodies selected from the group of AlN and Si 3 N 4 which can be sintered to near theoretical densities at temperatures at least 200° C. lower than those required for the pure materials. Such bodies are densified through the addition of a metal fluoride selected from the group of aluminum, barium, calcium, srtrontium, yttrium, the lanthanide rare earth metals, and mixtures thereof. Up to 80% by weight of said metal fluoride may be included but, generally, such additions will be held between 5-30% by weight. AlN bodies exhibiting very high thermal conductivity can be prepared by sintering with a metal fluoride selected from the group of barium, calcium, strontium, yttrium, the lanthanide rare earth metals, and mixtures thereof.
Inventors
- 👤 Pronob Bardhan
- 👤 Gregory A. Merkel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 06:14
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/58; C04B35/584; C04B35/593; C04B35/581
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
91 words
A sintered nitride-based ceramic body of near theoretical density selected from the group consisting of AlN containing, as analyzed by weight, about 0.02-25% of a metal selected from the group consisting of Al, Ba, Ca, Sr, Y, a lanthanide rare earth metal, and mixtures of those metals, and about 0.005-10% fluorine, and Si 3 N 4 containing, as analyzed by weight, about 0.02-25% of a metal selected from the group consisting of Al, Ba, Ca, Sr, Y, a lanthanide rare earth metal, and mixtures of those metals, and about 0.005-10% fluorine.
Claim 2
Dependent Claim
91 words
A sintered nitride-based ceramic body of near theoretical density selected from the group consisting of AlN containing, as analyzed by weight, about 0.02-25% of a metal selected from the group consisting of Al, Ba, Ca, Sr, Y, a lanthanide rare earth metal, and mixtures of those metals, and about 0.005-10% fluorine, and Si 3 N 4 containing, as analyzed by weight, about 0.02-25% of a metal selected from the group consisting of Al, Ba, Ca, Sr, Y, a lanthanide rare earth metal, and mixtures of those metals, and about 0.005-10% fluorine.
Claim 3
Dependent Claim
27 words
A ceramic body according to claim 1 wherein said metal is present in about 0.1-10% by weight and said fluorine is present in about 0.005-7% by weight.
Claim 4
Independent Claim
83 words
A method for preparing an AlN-based ceramic body of near theoretical density comprising the steps of: (a) combining an AlN-based material with about 1-80% by weight of a metal fluoride selected from the group consisting of AlF 3 , BaF 3 , CaF 2 , SrF 2 , YF 3 , a fluoride of a lanthanide rare earth metal, and mixtures of those metal fluorides; and (b) sintering that combination of AlN-based material and metal fluoride at a temperature between about 1400°-2000° C.
Claim 5
Independent Claim
83 words
A method for preparing an AlN-based ceramic body of near theoretical density comprising the steps of: (a) combining an AlN-based material with about 1-80% by weight of a metal fluoride selected from the group consisting of AlF 3 , BaF 3 , CaF 2 , SrF 2 , YF 3 , a fluoride of a lanthanide rare earth metal, and mixtures of those metal fluorides; and (b) sintering that combination of AlN-based material and metal fluoride at a temperature between about 1400°-2000° C.
Claim 6
Dependent Claim
17 words
A method according to claim 3 wherein said metal fluoride is present in about 5-30% by weight.
Claim 7
Dependent Claim
15 words
A method according to claim 3 wherein said sintering temperature ranges between about 1400°-1900° C.
Claim 8
Dependent Claim
98 words
A sintered body of AlN-based material exhibiting near theoretical density and a thermal conductivity greater than 70 W/m.K consisting essentially of AlN and sufficient metal fluoride selected from the group consisting of BaF 2 , CaF 2 , SrF 2 , YF 3 , a fluoride of a lanthanide rare earth metal, and mixtures of those fluorides, to react essentially completely with the Al 2 O 3 content present in the starting AlN so as to leave essentially no separate phase selected from the group consisting of Al 2 O 3 , Al-O-N, and mixtures of those phases.
Claim 9
Dependent Claim
98 words
A sintered body of AlN-based material exhibiting near theoretical density and a thermal conductivity greater than 70 W/m.K consisting essentially of AlN and sufficient metal fluoride selected from the group consisting of BaF 2 , CaF 2 , SrF 2 , YF 3 , a fluoride of a lanthanide rare earth metal, and mixtures of those fluorides, to react essentially completely with the Al 2 O 3 content present in the starting AlN so as to leave essentially no separate phase selected from the group consisting of Al 2 O 3 , Al-O-N, and mixtures of those phases.
Claim 10
Dependent Claim
32 words
A sintered AlN body according to claim 6 wherein said metal is present, as analyzed by weight, in about 0.02-25% and said fluorine is present, as analyzed by weight, in about 0.005-10%.
Claim 11
Independent Claim
95 words
A method for preparing a Si 3 N 4 -based ceramic body of near theoretical density comprising the steps of: (a) combining a Si 3 N 4 -based material with about 1-80% by weight of a metal fluoride selected from the group consisting of AlF 3 , BaF 3 , CaF 2 , SrF 2 , YF 3 , a fluoride of a lanthanide rare earth metal, and mixtures of those metal fluorides; and (b) sintering the combination of Si 3 N 4 -based material and metal fluoride at a temperature between about 1400°-1800° C.
Claim 12
Independent Claim
95 words
A method for preparing a Si 3 N 4 -based ceramic body of near theoretical density comprising the steps of: (a) combining a Si 3 N 4 -based material with about 1-80% by weight of a metal fluoride selected from the group consisting of AlF 3 , BaF 3 , CaF 2 , SrF 2 , YF 3 , a fluoride of a lanthanide rare earth metal, and mixtures of those metal fluorides; and (b) sintering the combination of Si 3 N 4 -based material and metal fluoride at a temperature between about 1400°-1800° C.
Claim 13
Dependent Claim
17 words
A method according to claim 8 wherein said metal fluoride is present in about 5-30% by weight.
Claim 14
Dependent Claim
14 words
A method according to claim 8 wherein said sintering temperature ranges about 1400°-1700° C.
References Cited (Backward Citations)
US2618565A
Cited
US3108887A
Cited
GB949471A
Cited
US3238018A
Cited
GB978734A
Cited
SU571497A1
Cited
US4119475A
Cited
US4122140A
Cited
US4146379A
Cited
US4540673A
Cited
JPS5855375A
Cited
US4435513A
Cited
JPS5950077A
Cited
GB2129788A
Cited
US4591537A
Cited
EP0147101A2
Cited
JPS60195058A
Cited
EP0166073A2
Cited
US4636480A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-01-11 | 1991-07-13 | 1992-01-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-01-11 | 1995-07-13 | 1996-01-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-01-11 | 1999-07-13 | 2000-01-12 | $7700.00 | Window Closed / Lapsed |