US4298385A
Expired / Lapsed
US
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High-strength ceramic bodies
Assignee: Max-Planck-Gesellschaft zur Förderung der Wissenschaften eV
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Filing: 1980-07-14
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Granted: 1981-11-03
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Expires: 2000-07-14
Abstract
Abstract A sintered ceramic body of high toughness, consisting of an isotropic ceramic matrix (e.g. Al 2 O 3 ) and at least one therein-dispersed phase (ZrO 2 , HzO 2 ) of ceramic embedment material formed from a powder consisting of particles having an average diameter from 0.3 to 1.25 μm, wherein the ceramic embedment material is present in different enantiotropic solid modifications at the firing temperature of the ceramic body and below the firing temperature, whose densities are substantially different, and the ceramic body is shot through with extremely fine microfractures in high density.
Inventors
- 👤 Nils Claussen
- 👤 Jorg Steeb
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:24
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/515; C04B35/56; C04B35/565; C04B35/575; B; B32; B32B; B32B18/00; C04B35/01; C04B35/10; C04B35/111; C04B35/117; C04B35/119; C04B35/58; C04B35/584; C04B35/593; C04B35/622; C04B35/64; C04B35/645; F; F01; F01D; F01D5/00; F01D5/12; F01D5/28; F01D5/284; C04B2235/00; C04B2235/65; C04B2235/656; C04B2235/6567; C04B2237/00; C04B2237/30; C04B2237/32; C04B2237/34; C04B2237/343; C04B2237/345; C04B2237/348; C04B2237/50; C04B2237/70; C04B2237/704
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
83 words
A sintered ceramic body of high toughness, consisting of an isotropic ceramic matrix and at least one therein-dispersed phase of ceramic embedment material formed from a powder consisting of particles having an average diameter from 0.3 to 1.25 μm, wherein the ceramic embedment material is present in different enantiotropic solid modifications at the firing temperature of the ceramic body and below the firing temperature, whose densities are substantially different, and the ceramic body is shot through with extremely fine microfractures in high density.
Claim 2
Dependent Claim
83 words
A sintered ceramic body of high toughness, consisting of an isotropic ceramic matrix and at least one therein-dispersed phase of ceramic embedment material formed from a powder consisting of particles having an average diameter from 0.3 to 1.25 μm, wherein the ceramic embedment material is present in different enantiotropic solid modifications at the firing temperature of the ceramic body and below the firing temperature, whose densities are substantially different, and the ceramic body is shot through with extremely fine microfractures in high density.
Claim 3
Dependent Claim
20 words
Ceramic body of claim 1, wherein the ceramic embedment material has a smaller coefficient of expansion than the ceramic matrix.
Claim 4
Dependent Claim
15 words
Ceramic body of claim 1, wherein the embedment material consists of unstabilized zirconium dioxide particles.
Claim 5
Dependent Claim
16 words
Ceramic body of claim 1, wherein the ceramic matrix consists of Al 2 O 3 .
Claim 6
Dependent Claim
23 words
Ceramic body of claim 2, wherein the matrix consists of Al 2 O 3 and the embedment material of unstabilized ZrO 2 particles.
Claim 7
Dependent Claim
23 words
Ceramic body of claim 5, having a ZrO 2 content of 4 to 25 volume-percent, the balance being Al 2 O 3 .
Claim 8
Dependent Claim
55 words
Ceramic body of claim 1, wherein the ceramic matrix and ceramic embedment material constitute ground material and an additionally embedded phase which in turn consists of a ceramic matrix and at least one phase dispersed therein of ceramic embedment material, but has a ceramic embedment material content different from the content of the ground material.
Claim 9
Dependent Claim
25 words
Ceramic body of claim 7, wherein the additionally embedded phase consists of the same ceramic matrix and the same embedment material as the ground material.
Claim 10
Dependent Claim
33 words
Ceramic body of claim 8, wherein the difference of the contents of the additionally embedded phase and that of the ground material of unstabilized ZrO 2 particles amounts to at least 3 volume-percent.
Claim 11
Dependent Claim
30 words
Ceramic body of claim 9, wherein the content of unstabilized ZrO 2 particles in the additionally embedded phase is at least 3 volume-percent higher than that of the ground material.
Claim 12
Dependent Claim
27 words
Ceramic body of claim 10, wherein the additionally embedded phase contains 12 to 20 volume-percent and the ground material 9 to 17 volume-percent of ZrO 2 .
Claim 13
Dependent Claim
13 words
High-temperature gas turbine element comprising a ceramic body as claimed in claim 1.
Claim 14
Dependent Claim
15 words
Ceramic body as claimed in claim 1, wherein the embedment material is HfO 2 .
Claim 15
Dependent Claim
138 words
Sintered ceramic body of high toughness consisting essentially of a ceramic matrix of Al 2 O 3 and at least one phase of ceramic embedment material formed from unstabilized ZrO 2 particles having an average diameter of from 0.3 to 1.25 μm and having a different coefficient of expansion from that of the Al 2 O 3 and present in from 4 to 25 volume percent and in different solid modifications having different densities at and below the firing temperature, wherein the ceramic embedment is dispersed into the ceramic matrix and is thereafter shaped, fired and cooled to effect stresses due to the different densities of the modifications and the different coefficients of expansion of the matrix and embedment whereby high toughness results and wherein the ceramic body is shot through with extremely fine microfractures in high density.
Claim 16
Dependent Claim
138 words
Sintered ceramic body of high toughness consisting essentially of a ceramic matrix of Al 2 O 3 and at least one phase of ceramic embedment material formed from unstabilized ZrO 2 particles having an average diameter of from 0.3 to 1.25 μm and having a different coefficient of expansion from that of the Al 2 O 3 and present in from 4 to 25 volume percent and in different solid modifications having different densities at and below the firing temperature, wherein the ceramic embedment is dispersed into the ceramic matrix and is thereafter shaped, fired and cooled to effect stresses due to the different densities of the modifications and the different coefficients of expansion of the matrix and embedment whereby high toughness results and wherein the ceramic body is shot through with extremely fine microfractures in high density.
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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) | 1984-11-02 | 1985-05-04 | 1985-11-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-11-02 | 1989-05-04 | 1989-11-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-11-02 | 1993-05-04 | 1993-11-03 | $7700.00 | Window Closed / Lapsed |