Patent US4694238A successfully refreshed from Google Patents.
US4595663A
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Sintered ceramic shaped article wholly or predominantly of eutectic microstructure constituents
Assignee: Sandvik AB
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Filing: 1984-01-09
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Granted: 1986-06-17
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Expires: 2004-01-09
Abstract
Abstract Ceramic shaped articles are disclosed which are formed of dense, non-metallic, mechanically resistant materials and contain eutectic constituents consisting of zirconium oxide, hafnium oxide and at least one other high-melting oxide and mixtures thereof. The composition exhibits excellent hardness, wear properties and bending strength. A method for preparing the articles is also disclosed wherein the appropriate mixture in a hypoeutectic, eutectic, or hypereutectic ratio is heated to its melting point, poured into a preheated mold and cooled.
Inventors
- 👤 Ulrich Krohn
- 👤 Hans Olapinski
- 👤 Ulf Dworak
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 07:33
CPC Classifications
F; F16; F16D; F16D65/00; F16D65/02; F16D65/12; F16D65/125; C; C04; C04B; C04B35/00; C04B35/01; C04B35/10; C04B35/111; C04B35/117; C04B35/119; C04B35/48; C04B35/486; C04B35/488; C04B35/4885; C04B35/622; C04B35/653; C04B35/657; Y; Y10; Y10T; Y10T407/00; Y10T407/27; Y10T82/00; Y10T82/10
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
127 words
In a sintered ceramic shaped article in the form of cutting tools, turbine blades, and similar articles which exhibit excellent hardness wear properties and bending strength, formed by sintering or hot pressing a mixture of dense, non-metallic, mechanically resistant ceramic powders, the improvement which comprise said mixture consisting wholly or predominantly of eutectic microstructures selected from the group consisting of aluminum oxide/zirconium oxide, beryllium oxide/zirconium oxide, aluminum oxide/hafnium oxide, aluminum oxide/zirconium oxide/ytterbium oxide, aluminum oxide/hafnium oxide/yttrium oxide, aluminum oxide/hagnium oxide/ytterbium oxide, aluminum oxide/zirconium oxide/yttrium oxide, aluminum oxide/magnesium oxide/zirconium oxide, and aluminum oxide/magnesium oxide/hafnium oxide and wherein particles of zirconium oxide and hafnium oxide within the eutectic microstructures are in an extremely fine and homogenous distribution and are present to a substantial extent in a metastable tetragonal modification.
Claim 2
Dependent Claim
127 words
In a sintered ceramic shaped article in the form of cutting tools, turbine blades, and similar articles which exhibit excellent hardness wear properties and bending strength, formed by sintering or hot pressing a mixture of dense, non-metallic, mechanically resistant ceramic powders, the improvement which comprise said mixture consisting wholly or predominantly of eutectic microstructures selected from the group consisting of aluminum oxide/zirconium oxide, beryllium oxide/zirconium oxide, aluminum oxide/hafnium oxide, aluminum oxide/zirconium oxide/ytterbium oxide, aluminum oxide/hafnium oxide/yttrium oxide, aluminum oxide/hagnium oxide/ytterbium oxide, aluminum oxide/zirconium oxide/yttrium oxide, aluminum oxide/magnesium oxide/zirconium oxide, and aluminum oxide/magnesium oxide/hafnium oxide and wherein particles of zirconium oxide and hafnium oxide within the eutectic microstructures are in an extremely fine and homogenous distribution and are present to a substantial extent in a metastable tetragonal modification.
Claim 3
Dependent Claim
36 words
The ceramic shaped article of claim 1, wherein the variation in size between the crystallites of zirconium oxide, hafnium oxide and metal oxides within the eutectic microstructures differs less than three times from their mean value.
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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) | 1989-06-16 | 1989-12-16 | 1990-06-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-06-16 | 1993-12-16 | 1994-06-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-06-16 | 1997-12-16 | 1998-06-17 | $7700.00 | Window Closed / Lapsed |