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US4383957A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of sintering a ceramic composition

Assignee: Sumitomo Electric Industries Ltd
•
Filing: 1981-05-20
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Granted: 1983-05-17
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Expires: 2001-05-20
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Abstract

Abstract A ceramic sintered body with a high density and high surface smoothness is obtained by sintering a ceramic composition comprising oxides as a substantial or partial component in an atmosphere of CO gas or in a mixture of CO gas and an inert gas.

Inventors

  • 👤 Akira Yamakawa
  • 👤 Akira Doi
  • 👤 Yoshihiko Doi

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-27 06:16
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/10; C04B35/111; C04B35/117; C04B35/119; C04B35/622; C04B35/64

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 78 words
A method of sintering a ceramic material which comprises sintering at a temperature of 1200° to 2000° C., a ceramic composition comprising oxides selected from the group consisting of Al 2 O 3 , ZrO 2 and mixtures thereof as a substantial or partial component in an atmosphere of CO gas or mixed gases of CO gas and an inert gas, wherein the partial pressure of the CO gas ranges from 5 mm Hg to 760 mm Hg.
Claim 2
Independent Claim 78 words
A method of sintering a ceramic material which comprises sintering at a temperature of 1200° to 2000° C., a ceramic composition comprising oxides selected from the group consisting of Al 2 O 3 , ZrO 2 and mixtures thereof as a substantial or partial component in an atmosphere of CO gas or mixed gases of CO gas and an inert gas, wherein the partial pressure of the CO gas ranges from 5 mm Hg to 760 mm Hg.
Claim 3
Dependent Claim 20 words
The method of claim 1, wherein the inert gas is selected from the group consisting of argon, helium and nitrogen.
Claim 4
Dependent Claim 68 words
The method of claim 1, wherein the ceramic composition comprising oxides as a partial component is composed of predominant phases of aluminum oxide and a B1 type solid solution represented by M(C 1 N m O n ) in which M is a metal of Group IVa, Va or VIa and 1, m and n are molar ratios of carbon, nitrogen and oxygen with the relationship of 1+m+n=1.
Claim 5
Dependent Claim 19 words
The method of claim 1, wherein the sintering is carried out after removing adsorbed gases from the ceramic composition.
Claim 6
Dependent Claim 44 words
A method according to claim 1 in which a gas non-permeable sintered body is produced from said sintering method in which the said sintered body has a relative density of at least 95% and said sintered body is subjected to a hot isostatic press.

References Cited (Backward Citations)

GB665373A Cited
US3455682A Cited
US3469976A Cited
US3562371A Cited
US3574645A Cited
US3792142A Cited
US4041123A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1986-05-16 1986-11-15 1987-05-17 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1990-05-16 1990-11-15 1991-05-17 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1994-05-16 1994-11-15 1995-05-17 $7700.00 Window Closed / Lapsed

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