Patent US2014416A successfully refreshed from Google Patents.
Patent US4716133A successfully refreshed from Google Patents.
US4716133A
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US
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Method for production of silicon nitride sintered body
Assignee: Kyocera Corp
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Filing: 1986-03-31
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Granted: 1987-12-29
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Expires: 2006-03-31
Abstract
Abstract When a composite nitride obtained by nitriding a fine powder of an alloy comprising metallic silicon and a metal of the group IIIa of the Periodic Table is sintered, a highly homogeneous silicon nitride sintered body having a high strength can be obtained. This fine powder of the alloy and this composite nitride exert a function of promoting sintering of Si3N4.
Inventors
- 👤 Akito Horiuchi
- 👤 Kiyoshi Yokoyama
- 👤 Makoto Yoshida
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 23:22
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/58; C04B35/584; C04B35/591
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
63 words
A method for the production of a silicon nitride sintered body, which comprises molding a fine powder of an alloy comprising metallic silicon and a metal of the group IIIa of the Periodic Table, subjecting the molded body to a nitriding treatment by calcination in a nitrogen-containing atmosphere and sintering the nitrided molded body at a temperature higher than the nitriding treatment temperature.
Claim 2
Independent Claim
63 words
A method for the production of a silicon nitride sintered body, which comprises molding a fine powder of an alloy comprising metallic silicon and a metal of the group IIIa of the Periodic Table, subjecting the molded body to a nitriding treatment by calcination in a nitrogen-containing atmosphere and sintering the nitrided molded body at a temperature higher than the nitriding treatment temperature.
Claim 3
Dependent Claim
39 words
A method according to claim 1, wherein the fine powder of the alloy contains 70 to 99.9% by weight of metallic silicon and 0.1 to 30% by weight of the metal of the group IIIa of the Periodic Table.
Claim 4
Dependent Claim
23 words
A method according to claim 1, wherein the fine powder of the alloy has an average particle size of 0.5 to 10 μm.
Claim 5
Dependent Claim
21 words
A method according to claim 1, wherein the nitriding treatment is carried out at a temperature of 1300° to 1400° C.
Claim 6
Dependent Claim
18 words
A method according to claim 1, wherein sintering is carried out at a temperature higher than 1650° C.
Claim 7
Dependent Claim
31 words
A method according to claim 1, wherein the temperature is elevated subsequently to the nitriding treatment of the molded body and sintering of the molded body is carried out in situ.
Claim 8
Dependent Claim
39 words
A method according to claim 1, wherein a sintering aid is added to the fine powder of the alloy in an amount of up to 15% by weight based on the total composition, and the obtained composition is molded.
Claim 9
Independent Claim
72 words
A method for the production of a silicon nitride sintered body, which comprises calcining a fine powder of an alloy comprising metallic silicon and a metal of the group IIIa of the Periodic Table in a nitrogen-containing atmosphere to effect a nitriding treatment, molding the obtained nitride or a mixture of the obtained nitride and a sintering aid, and sintering the molded body at a temperature higher than the nitriding treatment temperature.
Claim 10
Independent Claim
72 words
A method for the production of a silicon nitride sintered body, which comprises calcining a fine powder of an alloy comprising metallic silicon and a metal of the group IIIa of the Periodic Table in a nitrogen-containing atmosphere to effect a nitriding treatment, molding the obtained nitride or a mixture of the obtained nitride and a sintering aid, and sintering the molded body at a temperature higher than the nitriding treatment temperature.
Claim 11
Dependent Claim
39 words
A method according to claim 8, wherein the fine powder of the alloy contains 70 to 99.9% by weight of metallic silicon and 0.1 to 30% by weight of a metal of the group IIIa of the Periodic Table.
Claim 12
Independent Claim
77 words
A method for the production of a silicon nitride sintered body, which comprises molding a composition comprising (a) 1 to 30% by weight of a fine powder of an alloy comprising metallic silicon and a metal of the group IIIa of the Periodic Table, (b) 70 to 99% by weight of a fine powder of silicon nitride and (c) up to 15% by weight of a sintering aid, and sintering the molded body in a nitrogen-containing atmosphere.
Claim 13
Independent Claim
77 words
A method for the production of a silicon nitride sintered body, which comprises molding a composition comprising (a) 1 to 30% by weight of a fine powder of an alloy comprising metallic silicon and a metal of the group IIIa of the Periodic Table, (b) 70 to 99% by weight of a fine powder of silicon nitride and (c) up to 15% by weight of a sintering aid, and sintering the molded body in a nitrogen-containing atmosphere.
Claim 14
Dependent Claim
36 words
A method according to claim 10, wherein the fine powder of the alloy contains metallic silicon and the metal of the group IIIa of the Periodic Table at a weight ratio of from 1/10 to 10/1.
Claim 15
Dependent Claim
18 words
A method according to claim 10, wherein sintering is carried out at a temperature higher than 1700° C.
Claim 16
Dependent Claim
28 words
A method according to claim 10, wherein sintering is carried out at a temperature of 1300° to 1400° C. and then at a temperature higher than 1700° C.
Claim 17
Independent Claim
77 words
A method for the production of a silicon nitride sintered body, which comprises sintering a composition comprising (i) 1 to 30% by weight of a composite nitride obtained by calcining a powder of an alloy comprising metallic silicon and a metal of the group IIIa of the Periodic Table, (ii) 70 to 99% by weight of a fine powder of silicon nitride and (iii) up to 15% by weight of a sintering aid in a nitrogen-containing atmosphere.
Claim 18
Independent Claim
77 words
A method for the production of a silicon nitride sintered body, which comprises sintering a composition comprising (i) 1 to 30% by weight of a composite nitride obtained by calcining a powder of an alloy comprising metallic silicon and a metal of the group IIIa of the Periodic Table, (ii) 70 to 99% by weight of a fine powder of silicon nitride and (iii) up to 15% by weight of a sintering aid in a nitrogen-containing atmosphere.
Claim 19
Dependent Claim
36 words
A method according to claim 14, wherein the fine powder of the alloy contains metallic silicon and the metal of the group IIIa of the Periodic Table at a weight ratio of from 1/10 to 10/1.
Claim 20
Dependent Claim
18 words
A method according to claim 14, wherein sintering is carried out at a temperature higher than 1700° C.
Claim 21
Dependent Claim
73 words
A composite nitride which is composed mainly of α-Si 3 N 4 and in which Si and a metal of the group IIIa of the Periodic Table are present at a weight ratio of from 99.9/0.1 to 70/30, said composite nitride being obtained by nitriding a fine powder of an alloy containing metallic silicon and the metal of the group IIIa of the Periodic Table at said weight ratio in a nitrogen atmosphere.
Claim 22
Dependent Claim
73 words
A composite nitride which is composed mainly of α-Si 3 N 4 and in which Si and a metal of the group IIIa of the Periodic Table are present at a weight ratio of from 99.9/0.1 to 70/30, said composite nitride being obtained by nitriding a fine powder of an alloy containing metallic silicon and the metal of the group IIIa of the Periodic Table at said weight ratio in a nitrogen atmosphere.
Claim 23
Dependent Claim
33 words
A composite nitride as set forth in claim 17, wherein Si and the metal of the group IIIa of the Periodic Table are present at a weight ratio of from 99.5/0.5 to 90/10.
References Cited (Backward Citations)
US4322257A
Cited
US4401617A
Cited
US4434238A
Cited
US4240831A
Cited
US4350529A
Cited
US4365022A
Cited
US4568516A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-12-28 | 1991-06-29 | 1991-12-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-12-28 | 1995-06-29 | 1995-12-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-12-28 | 1999-06-29 | 1999-12-29 | $7700.00 | Window Closed / Lapsed |