US4978645A
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Silicon nitride sintered body
Assignee: Toyota Central R&D Labs Inc
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Filing: 1989-04-07
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Granted: 1990-12-18
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Expires: 2009-04-07
Abstract
Abstract A silicon nitride sintered body composed of α'-silicon nitride and β'-silicon nitride, which are present in the ratio of 0.05-0.50 to 0.50-0.95 in terms of the peak strength ratio of X-ray diffraction, and have very small crystal grain size and specific compositions. The sintered body has high strength and high toughness and is superior in oxidation resistance.
Inventors
- 👤 Yoshio Ukyo
- 👤 Shigetaka Wada
- 👤 Kazumasa Takatori
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 12:33
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/58; C04B35/584; C04B35/593; C04B35/5935
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
80 words
A sialon sintered body consisting essentially of α'-silicon nitride and β'-silicon nitride, the ratio of said α'-silicon nitride and said β'-silicon nitride in terms of the peak strength ratio of X-ray diffraction being 0.05-0.50 to 0.95-0.50, and said α'-silicon nitride having an average grain size of crystal not more than 2.0 μm and said β'-silicon nitride having an average grain size of crystal not more than 5.0 μm in major axis and not more than 1.0 μm in minor axis.
Claim 2
Dependent Claim
80 words
A sialon sintered body consisting essentially of α'-silicon nitride and β'-silicon nitride, the ratio of said α'-silicon nitride and said β'-silicon nitride in terms of the peak strength ratio of X-ray diffraction being 0.05-0.50 to 0.95-0.50, and said α'-silicon nitride having an average grain size of crystal not more than 2.0 μm and said β'-silicon nitride having an average grain size of crystal not more than 5.0 μm in major axis and not more than 1.0 μm in minor axis.
Claim 3
Dependent Claim
68 words
A sialon nitride sintered body as claimed in claim 1, wherein said α'-silicon nitride is one which is represented by the general formula of M x (Si,Al) 12 (O,N) 16 where 0<x2, and M denotes at least one of Li, Mg, Ca, and Y, and said β'-silicon nitride is one which is represented by the general formula of Si 6-y Al y O y N 8-y where 0<y<4.2.
Claim 4
Dependent Claim
35 words
A sialon nitride sintered body as claimed in claim 1, wherein the ratio of said α'-silicon nitride and said β'-silicon nitride in terms of the peak strength ratio of X-ray diffraction is 0.07-0.35 to 0.93-0.65.
Claim 5
Dependent Claim
33 words
A sialon nitride sintered body as claimed in claim 1, wherein said β'-silicon nitride has such an average grain size of crystal that the major axis is greater than twice the minor axis.
Claim 6
Dependent Claim
45 words
A sialon nitride sintered body as claimed in claim 1, wherein said α'-silicon nitride has an average grain size of crystal not more than 1.0 μm and said β'-silicon nitride has an average grain size of crystal not more than 2.5 μm in minor axis.
Claim 7
Dependent Claim
66 words
A sialon sintered body as claimed in claim 1, wherein said α'-silicon nitride is one which is represented by the general formula M x (Si,Al) 12 (O,N) 16 where 0<x≦0.3, and M is at least one of Li, Mg, Ca, and y, and said β'-silicon nitride is one which is represented by the general formula of Si 6-y Al y O y N 8-y where 0<y≦1.0.
Claim 8
Dependent Claim
32 words
A sialon sintered body as claimed in claim 6, wherein said β'-silicon nitride has such an average grain size of crystal that the major axis is greater than twice the minor axis.
Claim 9
Dependent Claim
53 words
A sialon sintered body as claimed in claim 6, wherein said α'-silicon nitride has an average grain size of crystal not more than 1.0 μm and said β'-silicon nitride has an average grain size of crystal not more than 2.5 μm in major axis and not more than 0.5 μm in minor axis.
References Cited (Backward Citations)
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