US4740238A
Expired / Lapsed
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Platelet-containing tantalum powders
Assignee: Taniobis Co Ltd
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Filing: 1987-03-26
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Granted: 1988-04-26
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Expires: 2007-03-26
Abstract
Abstract An ingot-derived unagglomerated (or preagglomerated) tantalum powder composition includes a platelet tantalum powder having an average FSSS of less than two micrometers, preferably in the range of 0.6 to 1.1 micrometers, a Scott density not greater than about 30 g/in 3 , and a BET surface area of at least 0.7 m 2 /g. In one embodiment of the invention, such powder is agglomerated and milled to form a tantalum powder product having a particle size of about 2 to 3 micrometers, a BET surface area of about 0.43 m 2 /g, a Scott density in the range of 18 to 27 g/in 3 .
Inventors
- 👤 Edward K. Schiele
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 07:08
CPC Classifications
H; H01; H01G; H01G9/00; H01G9/004; H01G9/04; H01G9/048; H01G9/052; H01G9/0525; B; B22; B22F; B22F1/00; B22F1/05
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
46 words
An ingot-derived unagglomerated tantalum powder composition comprising a platelet tantalum powder having an average Fisher sub-sieve particle size of less than two micrometers, a Scott density not greater than about 30 g/in 3 and a BET surface area of at least about 0.7 m 2 /g.
Claim 2
Dependent Claim
46 words
An ingot-derived unagglomerated tantalum powder composition comprising a platelet tantalum powder having an average Fisher sub-sieve particle size of less than two micrometers, a Scott density not greater than about 30 g/in 3 and a BET surface area of at least about 0.7 m 2 /g.
Claim 3
Dependent Claim
39 words
The powder set forth in claim 1 wherein said Fisher sub-sieve size is in the range of about 0.6 to 1.1 micrometers, and said BET surface area is in the range of about 0.76 to 1.44 m 2 /g.
Claim 4
Dependent Claim
42 words
An ingot-derived agglomerated tantalum powder composition comprising a platelet tantalum powder having a Fisher sub-sieve size of about two micrometers, a Scott density of about 13.5 g/in 3 , and a BET surface area on the order of 0.44 m 2 /g.
Claim 5
Dependent Claim
42 words
An ingot-derived agglomerated tantalum powder composition comprising a platelet tantalum powder having a Fisher sub-sieve size of about two micrometers, a Scott density of about 13.5 g/in 3 , and a BET surface area on the order of 0.44 m 2 /g.
Claim 6
Dependent Claim
23 words
The powder set forth in claim 3 wherein said Scott density is in the range of about 18 to 27 g/in 3 .
Claim 7
Dependent Claim
82 words
An ingot-derived agglomerated tantalum powder composition comprising a granular tantalum powder of tetrahedral morphology and at least 25 w/o platelet tantalum powder having a Fisher sub-sieve particle size of not more than 2.0 micrometers and a BET surface area of at least 0.43 m 2 /g, said composition having a Scott density of at least about 25 g/in 3 , a composite Fisher sub-sieve size of at least about 2.0 micrometers and an oxygen content of not more than about 2000 ppm.
Claim 8
Dependent Claim
82 words
An ingot-derived agglomerated tantalum powder composition comprising a granular tantalum powder of tetrahedral morphology and at least 25 w/o platelet tantalum powder having a Fisher sub-sieve particle size of not more than 2.0 micrometers and a BET surface area of at least 0.43 m 2 /g, said composition having a Scott density of at least about 25 g/in 3 , a composite Fisher sub-sieve size of at least about 2.0 micrometers and an oxygen content of not more than about 2000 ppm.
Claim 9
Independent Claim
66 words
A method of forming platelet tantalum powders comprising the steps of: (a) providing an ingot-derived precursor tantalum powder, and (b) ball-milling said precursor powder for a time sufficient to form a platelet power having an average FSSS of less than about 2 micrometers, a Scott density not greater than about 30 g/in 3 and a BET surface area of at least about 0.7 in 2 /g.
Claim 10
Independent Claim
66 words
A method of forming platelet tantalum powders comprising the steps of: (a) providing an ingot-derived precursor tantalum powder, and (b) ball-milling said precursor powder for a time sufficient to form a platelet power having an average FSSS of less than about 2 micrometers, a Scott density not greater than about 30 g/in 3 and a BET surface area of at least about 0.7 in 2 /g.
Claim 11
Dependent Claim
27 words
The method set forth in claim 6 comprising the additional step, prior to said step (b), of milling said precursor in a slurry which includes 1-1-1 trichloroethane.
Claim 12
Dependent Claim
20 words
The method set forth in claim 7 wherein said precursor powder has an FSSS of about 1.7 to 3.1 micrometers.
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) | 1991-04-26 | 1991-10-26 | 1992-04-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-04-26 | 1995-10-26 | 1996-04-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-04-26 | 1999-10-26 | 2000-04-26 | $7700.00 | Window Closed / Lapsed |