Patent US4590090A successfully refreshed from Google Patents.
US4590090A
Expired / Lapsed
US
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Method for making interdiffused, substantially spherical ceramic powders
Assignee: General Electric Co
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Filing: 1982-07-28
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Granted: 1986-05-20
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Expires: 2002-07-28
Abstract
Abstract Substantially homogeneous, substantially spherical interdiffused metallic oxide particles, especially useful in plasma spraying applications, are readily and economically prepared from constituent metal oxide powders by the method of this invention which includes the step of heating a mass of discrete agglomerated particles under conditions of temperature and time sufficient to interdiffuse the constituent metallic oxides within the agglomerates, but insufficient to sinter the agglomerates together.
Inventors
- 👤 Paul A. Siemers
- 👤 Casimir W. Krystyniak
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 06:34
CPC Classifications
C; C01; C01G; C01G25/00; C01G25/02; C23; C23C; C23C4/00; C23C4/04; C23C4/10; C23C4/11; C01P; C01P2002/00; C01P2002/70; C01P2002/77; C01P2004/00; C01P2004/30; C01P2004/32; C01P2004/50
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
159 words
A method of forming an interdiffused oxide coating of zirconia and yttria which comprises providing a finely divided zirconia powder of monoclinic crystal structure, providing a finely divided yttria powder of body centered cubic crystal structure, dispersing the oxides in water containing less than 5% non-volatile organic binder to form a sprayable slurry, milling the slurry to intimately intermix the oxides, spray drying the milled slurry to form usable binder bearing particles in the desired size range of about 44 to about 74 μm, separating the oversize and undersize particles from the usable particles, heating the usable particles at a temperature which drives off the binder, heating the particles at a temperature above 1400° C. for a time to form a friable mass of cubic solid solution of Y 2 O 3 in ZrO 2 , pulverizing the friable mass into free flowing particles, and plasma spraying the particles onto a receiving surface to form an interdiffused oxide coating.
Claim 2
Independent Claim
159 words
A method of forming an interdiffused oxide coating of zirconia and yttria which comprises providing a finely divided zirconia powder of monoclinic crystal structure, providing a finely divided yttria powder of body centered cubic crystal structure, dispersing the oxides in water containing less than 5% non-volatile organic binder to form a sprayable slurry, milling the slurry to intimately intermix the oxides, spray drying the milled slurry to form usable binder bearing particles in the desired size range of about 44 to about 74 μm, separating the oversize and undersize particles from the usable particles, heating the usable particles at a temperature which drives off the binder, heating the particles at a temperature above 1400° C. for a time to form a friable mass of cubic solid solution of Y 2 O 3 in ZrO 2 , pulverizing the friable mass into free flowing particles, and plasma spraying the particles onto a receiving surface to form an interdiffused oxide coating.
Claim 3
Independent Claim
159 words
A method of forming an interdiffused oxide coating of zirconia and ceria which comprises providing a finely divided zirconia powder of monoclinic crystal structure, providing a finely divided ceria powder of face centered cubic crystal structure, dispersing the oxides in water containing less than 5% non-volatile organic binder to form a sprayable slurry, milling the slurry to intimately intermix the oxides, spray drying the milled slurry to form usable binder bearing particles in the desired size range of about 44 to about 74 μm, separating the oversize and undersize particles from the usable particles, heating the usable particles at a temperature which drives off the binder, heating the particles at a temperature above 1400° C. for a time to form a friable mass of substantially homogeneous interdiffusion of ceria and zirconia comprising tetragonal and cubic phases, pulverizing the friable mass into free flowing particles, and plasma spraying the particles onto a receiving surface to form an interdiffused oxide coating.
Claim 4
Independent Claim
159 words
A method of forming an interdiffused oxide coating of zirconia and ceria which comprises providing a finely divided zirconia powder of monoclinic crystal structure, providing a finely divided ceria powder of face centered cubic crystal structure, dispersing the oxides in water containing less than 5% non-volatile organic binder to form a sprayable slurry, milling the slurry to intimately intermix the oxides, spray drying the milled slurry to form usable binder bearing particles in the desired size range of about 44 to about 74 μm, separating the oversize and undersize particles from the usable particles, heating the usable particles at a temperature which drives off the binder, heating the particles at a temperature above 1400° C. for a time to form a friable mass of substantially homogeneous interdiffusion of ceria and zirconia comprising tetragonal and cubic phases, pulverizing the friable mass into free flowing particles, and plasma spraying the particles onto a receiving surface to form an interdiffused oxide coating.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-05-19 | 1989-11-18 | 1990-05-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-05-19 | 1993-11-18 | 1994-05-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-05-19 | 1997-11-18 | 1998-05-20 | $7700.00 | Window Closed / Lapsed |