US4412008A
Expired / Lapsed
US
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Composite sinter of silicon nitride/boron nitride and method for manufacturing thereof
Assignee: SHINAGAWA SHIROENGA KK
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Filing: 1981-02-11
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Granted: 1983-10-25
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Expires: 2001-02-11
Abstract
Abstract A composite sinter of silicon nitride/boron nitride, which consists essentially of, in weight percentage, silicon nitride within the range of from 60 to 97% and boron nitride within the range of from 3 to 40%, and wherein said boron nitride is present as a dispersed phase in the network of said silicon nitride; said composite sinter of silicon nitride/boron nitride being manufactured by the steps of: kneading a silicon powder within the range of from 47.3 to 95.1 wt.% and a boron nitride powder within the range of from 4.9 to 52.7 wt. %, as raw materials, with the use of an organic solvent solution containing a dispersant and a binder; press-forming the resultant kneaded mixture to prepare a green compact; sintering said green compact in a non-oxidizing atmosphere at a temperature within the range of from 1,100 DEG to 1,300 DEG C. to prepare a sinter having a strength permitting machining; machining said sinter into prescribed dimensions; and sintering again the resultant machined sinter in a nitrogen atmosphere at a temperature within the range of from 1,250 DEG to 1,450 DEG C. to nitrify the same, thereby improving strength and thermal shock resistance of said sinter.
Inventors
- 👤 Akira Miyamoto
- 👤 Masaru Ishikawa
- 👤 Masaaki Nishi
- 👤 Kenki Ishizawa
- 👤 Akira Shiranita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 11:56
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/58; C04B35/584; C04B35/591
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
175 words
A method for manufacturing a composite sinter of silicon nitride/boron nitride which consists essentially of a network of silicon nitride within the range of from 60 to 97 wt. % and boron nitride within the range of from 3 to 40 wt. % as a dispersed phase in said network of said silicon nitride which comprises: kneading silicon powder within the range of from 47.3 to 95.1 wt. % and boron nitride powder within the range of from 4.9 to 52.7 wt. %, as raw materials, with an organic solvent solution containing a dispersant and a binder; press-forming the resultant kneaded mixture to prepare a green compact; sintering said green compact in a non-oxidizing atmosphere at a temperature within the range of from 1,100° to 1,300° C. to prepare a sinter having a strength permitting machining; machining said sinter; and, sintering said machined sinter in a nitrogen atmosphere at a temperature within the range of from 1,250° to 1,450° C. to nitrify the same, thereby improving the strength and thermal shock resistance of said sinter.
Claim 2
Independent Claim
175 words
A method for manufacturing a composite sinter of silicon nitride/boron nitride which consists essentially of a network of silicon nitride within the range of from 60 to 97 wt. % and boron nitride within the range of from 3 to 40 wt. % as a dispersed phase in said network of said silicon nitride which comprises: kneading silicon powder within the range of from 47.3 to 95.1 wt. % and boron nitride powder within the range of from 4.9 to 52.7 wt. %, as raw materials, with an organic solvent solution containing a dispersant and a binder; press-forming the resultant kneaded mixture to prepare a green compact; sintering said green compact in a non-oxidizing atmosphere at a temperature within the range of from 1,100° to 1,300° C. to prepare a sinter having a strength permitting machining; machining said sinter; and, sintering said machined sinter in a nitrogen atmosphere at a temperature within the range of from 1,250° to 1,450° C. to nitrify the same, thereby improving the strength and thermal shock resistance of said sinter.
Claim 3
Dependent Claim
22 words
The method of claim 1, wherein: said silicon powder and said boron nitride powder are of a purity of at least 97%.
Claim 4
Dependent Claim
46 words
The method of claim 1 or 2, wherein: a silicon nitride powder is added, as an additional raw material, to said raw materials, at a ratio of up to 40 wt. % relative to the total quantity of said silicon nitride powder and said silicon powder.
Claim 5
Dependent Claim
72 words
The method of claim 2 or 3, wherein: at least one oxide selected from the group consisting of magnesia (MgO), yttria (Y 2 O 3 ), aluminum (Al 2 O 3 ) and lanthanium oxide (La 2 O 3 ) is added, as a sintering assistant, to said raw materials, at a ratio of up to 10 wt. % relative to the total quantity of said sintering assistant and said raw materials.
Claim 6
Dependent Claim
79 words
The method of claim 4, wherein: at least one oxide selected from the group consisting of magnesia (MgO), yttria (Y 2 O 3 ), alumina (Al 2 O 3 ) and lanthanium oxide (La 2 O 3 ) is added, as a sintering assistant, to said raw materials and said additional raw material, at a ratio of up to 10 wt. % relative to the total quantity of said sintering assistant, said raw materials and said additional raw material.
Claim 7
Dependent Claim
158 words
A composite sinter manufacture of silicon nitride/boron nitride, which consists essentially of a network of silicon nitride within the range of from 60 to 90 wt. % and boron nitride within the range of from 3 to 40 wt. % as a dispersed phase in said network of said silicon nitride; said composite sinter manufacture being manufactured by the reaction sintering method comprising mixing silicon powder within the range of from 47.3 to 95.1 wt. % and boron nitride powder within the range of from 4.9 to 52.7 wt. % as raw materials with an organic solvent solution containing a dispersant and a binder; press-forming the mixture to form a green compact; sintering said green compact in a non-oxidizing atmosphere; and then sintering and nitrifying in a nitrogen atmosphere at a temperature within the range of from 1,250° to 1,450° C. to nitrify the silicon and form said composite sinter manufacture having improved strength and thermal shock resistance.
Claim 8
Dependent Claim
158 words
A composite sinter manufacture of silicon nitride/boron nitride, which consists essentially of a network of silicon nitride within the range of from 60 to 90 wt. % and boron nitride within the range of from 3 to 40 wt. % as a dispersed phase in said network of said silicon nitride; said composite sinter manufacture being manufactured by the reaction sintering method comprising mixing silicon powder within the range of from 47.3 to 95.1 wt. % and boron nitride powder within the range of from 4.9 to 52.7 wt. % as raw materials with an organic solvent solution containing a dispersant and a binder; press-forming the mixture to form a green compact; sintering said green compact in a non-oxidizing atmosphere; and then sintering and nitrifying in a nitrogen atmosphere at a temperature within the range of from 1,250° to 1,450° C. to nitrify the silicon and form said composite sinter manufacture having improved strength and thermal shock resistance.
Claim 9
Dependent Claim
24 words
The composite sinter manufacture of claim 6, wherein: said silicon powder and said boron nitride powder are of a purity of at least 97%.
Claim 10
Dependent Claim
47 words
The composite sinter manufacture of claim 6 or 7, wherein: silicon nitride powder is added, as an additional raw material, to said raw materials, at a ratio of up to 40 wt. % relative to the total quantity of said silicon nitride powder and said silicon powder.
Claim 11
Dependent Claim
74 words
The composite sinter manufacture of claim 6 or 7, wherein: at least one oxide selected from the group consisting of magnesia (MgO), yttria (Y 2 O 3 ), alumina (Al 2 O 3 ) and lanthanium oxide (La 2 O 3 ) is added, as a sintering assistant, to said raw materials, at a ratio of up to 10 wt. % relative to the total quantity of said sintering assistant and said raw materials.
Claim 12
Dependent Claim
81 words
The composite sinter manufacture of claim 8, wherein: at least one oxide selected from the group consisting of magnesia (MgO, yttria (Y 2 O 3 ), alumina (Al 2 O 3 ) and lanthanium oxide (La 2 O 3 ) is added, as a sintering assistant, to said raw materials and said additional raw material, at a ratio of up to 10 wt. % relative to the total quantity of said sintering assistant, said raw materials and said additional raw material.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1986-10-24 | 1987-04-25 | 1987-10-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-10-24 | 1991-04-25 | 1991-10-25 | $3760.00 | Window Closed / Lapsed |
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