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US4440707A Expired / Lapsed US ⏱️ 0.0 years remaining

Process for producing silicon nitride sintered products having high toughness

Assignee: Niterra Co Ltd
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Filing: 1982-09-29
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Granted: 1984-04-03
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Expires: 2002-09-29
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Abstract

Abstract A process for producing a silicon nitride sintered product having high toughness is described, comprising blending from 97 to 57% by weight of metallic silicon powder having a maximum particle size of 25 μm or less with from 1 to 15% by weight, calculated as TiN, of a TiN powder having a maximum particle size of 20 μm or less or a powder of titanium component capable of changing into TiN during reaction sintering, and from 2 to 28% by weight of one or more components selected from the group consisting of AlN, Al 2 O 3 , SiO 2 and oxides of rare earth elements, molding the resulting mixture, carrying out reaction sintering in a nonoxidizing atmosphere of a nitrogen gas or a nitrogen-containing mixed gas, and thereafter resintering in the same atmosphere at a temperature of from 1,600° C. to 2,200° C.

Inventors

  • 👤 Toru Shimamori
  • 👤 Yoshinori Hattori
  • 👤 Yasushi Matsuo

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-25 00:16
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/58; C04B35/584; C04B35/593

Claims Analysis

Total Claims: 3
Claim 1
Independent Claim 141 words
A process for producing a silicon nitride sintered product having high toughness comprising blending from 97 to 57% by weight of metallic silicon powder having a maximum particle size of 25 μm or less with from 1 to 15% by weight, calculated as TiN, of a TiN powder having a maximum particle size of 20 μm or less or a powder of titanium component capable of changing into TiN during reaction sintering, and from 2 to 28% by weight of one or more components selected from the group consisting of AlN, Al 2 O 3 , SiO 2 and oxides of rare earth elements, molding the resulting mixture, carrying out reaction sintering in a nonoxidizing atmosphere of a nitrogen gas or a nitrogen-containing mixed gas, and thereafter resintering in the same atmosphere at a temperature of from 1,600° to 2,200° C.
Claim 2
Dependent Claim 141 words
A process for producing a silicon nitride sintered product having high toughness comprising blending from 97 to 57% by weight of metallic silicon powder having a maximum particle size of 25 μm or less with from 1 to 15% by weight, calculated as TiN, of a TiN powder having a maximum particle size of 20 μm or less or a powder of titanium component capable of changing into TiN during reaction sintering, and from 2 to 28% by weight of one or more components selected from the group consisting of AlN, Al 2 O 3 , SiO 2 and oxides of rare earth elements, molding the resulting mixture, carrying out reaction sintering in a nonoxidizing atmosphere of a nitrogen gas or a nitrogen-containing mixed gas, and thereafter resintering in the same atmosphere at a temperature of from 1,600° to 2,200° C.
Claim 3
Dependent Claim 30 words
A process for producing a silicon nitride sintered product having high toughness according to claim 1, wherein resintering is carried out under a pressure of from 1 to 3,000 atm.

References Cited (Backward Citations)

US4127630A Cited
US4351787A Cited
JPS5622678A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1987-04-03 1987-10-03 1988-04-03 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1991-04-03 1991-10-03 1992-04-03 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1995-04-03 1995-10-03 1996-04-03 $7700.00 Window Closed / Lapsed

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