US4826791A
Expired / Lapsed
US
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Silicon carbide-alpha prime sialon beta prime sialon
Assignee: Kennametal PC Inc
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Filing: 1987-05-29
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Granted: 1989-05-02
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Expires: 2007-05-29
Abstract
Abstract A ceramic composite is provided possessing a combination of high fracture toughness, high hardness and high wear resistance. The composite contains SiC particles dispersed in a ceramic matrix of mainly sialon. The sialon is composed of about 10 to 67 weight percent alpha prime sialon, with the remainder, being beta prime sialon.
Inventors
- 👤 Pankaj K. Mehrotra
- 👤 Klaus-Markus Peters
- 👤 Joyce L. Swiokla
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 02:53
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/58; C04B35/597
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
74 words
A ceramic composite consisting essentially of: 5 to 50 v/o substantially equiaxed SiC particles dispersed in a ceramic matrix; said ceramic matrix consists essentially of sialon; said sialon composed of about 10 to about 67 w/o alpha prime sialon, with beta prime sialon forming the remainder of said sialon; said SiC particles have a median size of about 1.5 to 15 microns; and said ceramic composite having a density of at least 3.1 g/cc.
Claim 2
Dependent Claim
74 words
A ceramic composite consisting essentially of: 5 to 50 v/o substantially equiaxed SiC particles dispersed in a ceramic matrix; said ceramic matrix consists essentially of sialon; said sialon composed of about 10 to about 67 w/o alpha prime sialon, with beta prime sialon forming the remainder of said sialon; said SiC particles have a median size of about 1.5 to 15 microns; and said ceramic composite having a density of at least 3.1 g/cc.
Claim 3
Dependent Claim
21 words
The ceramic composite according to claim 1 wherein said SiC particles are present at a level of 15 to 30 v/o.
Claim 4
Dependent Claim
20 words
The ceramic composite according to claim 1 wherein said sialon is composed of at least 50 w/o alpha prime sialon.
Claim 5
Dependent Claim
20 words
The ceramic composite according to claim 2 wherein said sialon is composed of at least 50 w/o alpha prime sialon.
Claim 6
Dependent Claim
20 words
The ceramic composite according to claim 1 wherein said sialon is composed of at least 60 w/o alpha prime sialon.
Claim 7
Dependent Claim
20 words
The ceramic composite according to claim 2 wherein said sialon is composed of at least 60 w/o alpha prime sialon.
Claim 8
Dependent Claim
20 words
The ceramic composite according to claim 1 wherein said SiC particles have a median size between 2 to 9 microns.
Claim 9
Dependent Claim
31 words
The ceramic composite according to claim 1 having a hardness of at least 94.5 Rockwell A and a fracture toughness, K IC (E&C) of about 6 MPa m 1/2 or more.
Claim 10
Dependent Claim
16 words
The ceramic composite according to claim 8 wherein said hardness is at least 95.0 Rockwell A.
Claim 11
Dependent Claim
19 words
The ceramic composite according to claim 8 wherein said fracture toughness is at least 6.5 MPa m 1/2 .
Claim 12
Dependent Claim
19 words
The ceramic composite according to claim 9 wherein said fracture toughness is at least 6.5 MPa m 1/2 .
Claim 13
Dependent Claim
21 words
The ceramic composite according to claim 1 wherein said SiC particles are present at a level of 15 to 50 v/o.
Claim 14
Dependent Claim
21 words
The ceramic composite according to claim 1 wherein said SiC particles are present at a level of 5 to 30 v/o.
Claim 15
Dependent Claim
80 words
An article of manufacture composed of a ceramic composite consisting essentially of 5 to 50 v/o substantially equiaxed SiC particles dispersed in a ceramic matrix; said ceramic matrix consists essentially of sialon; said sialon composed of about 10 to about 67 w/o alpha prime sialon, with beta prime sialon forming the remainder of said sialon; said SiC particles have an average size of about 1.5 to 15 microns; and said ceramic composite having a density of at least 3.1 g/cc.
Claim 16
Dependent Claim
80 words
An article of manufacture composed of a ceramic composite consisting essentially of 5 to 50 v/o substantially equiaxed SiC particles dispersed in a ceramic matrix; said ceramic matrix consists essentially of sialon; said sialon composed of about 10 to about 67 w/o alpha prime sialon, with beta prime sialon forming the remainder of said sialon; said SiC particles have an average size of about 1.5 to 15 microns; and said ceramic composite having a density of at least 3.1 g/cc.
Claim 17
Dependent Claim
15 words
The article of manufacture according to claim 14 wherein said article is a seal ring.
Claim 18
Dependent Claim
14 words
The article of manufacture according to claim 14 wherein said article is a nozzle.
Claim 19
Dependent Claim
21 words
The article of manufacture according to claim 15 wherein said sialon is composed of 10 to 50 w/o alpha prime sialon.
Claim 20
Dependent Claim
60 words
The ceramic composite according to claim 1 wherein said ceramic matrix further consists essentially of a sintering aid residue in an amount sufficient to at least substantially encircle said SiC particles and thereby at least substantially separate said SiC particles from said sialon and wherein said sintering aid residue forms between about 0.1 and 15.0 w/o of said ceramic matrix.
Claim 21
Dependent Claim
60 words
The ceramic composite according to claim 4 wherein said ceramic matrix further consists essentially of a sintering aid residue in an amount sufficient to at least substantially encircle said SiC particles and thereby at least substantially separate said SiC particles from said sialon and wherein said sintering aid residue forms between about 0.1 and 15.0 w/o of said ceramic matrix.
Claim 22
Dependent Claim
60 words
The ceramic composite according to claim 14 wherein said ceramic matrix further consists essentially of a sintering aid residue in an amount sufficient to at least substantially encircle said SiC particles and thereby at least substantially separate said SiC particles from said sialon and wherein said sintering aid residue forms between about 0.1 and 15.0 w/o of said ceramic matrix.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-05-01 | 1992-10-31 | 1993-05-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-05-01 | 1996-10-31 | 1997-05-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-05-01 | 2000-10-31 | 2001-05-02 | $7700.00 | Window Closed / Lapsed |