Patent US4283228A successfully refreshed from Google Patents.
US4283228A
Expired / Lapsed
US
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Low temperature densification of PZT ceramics
Assignee: University of Illinois Foundation
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Filing: 1979-12-05
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Granted: 1981-08-11
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Expires: 1999-12-05
Abstract
Abstract Addition of from about 0.1 to about 6.0% by weight of V2O5 to (PZT)lead zirconate-lead titanate powder promotes rapid densification at temperatures below 1000 DEG C. and eliminates the need for PbO atmosphere control. Densification to greater than 98% of theoretical density is achieved with firing times as short as 1-5 minutes. Dielectric properties depend upon the amount of V2O5 added and upon the microstructure developed, but in general are equivalent to those reported for conventional PZT compositions.
Inventors
- 👤 Relva C. Buchanan
- 👤 Dale E. Wittmer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 06:53
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/48; C04B35/49; C04B35/491
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
60 words
A fired PZT ceramic composition characterized by a density of at least 98% of theoretical density which composition consists essentially of a major amount of lead zirconate-lead titanate having the formula Pb(ZrTi)O 3 wherein the Zr:Ti molar ratio ranges from about 65:35 to about 35:65, and from about 0.1 to about 6.0% by weight of V 2 O 5 .
Claim 2
Dependent Claim
60 words
A fired PZT ceramic composition characterized by a density of at least 98% of theoretical density which composition consists essentially of a major amount of lead zirconate-lead titanate having the formula Pb(ZrTi)O 3 wherein the Zr:Ti molar ratio ranges from about 65:35 to about 35:65, and from about 0.1 to about 6.0% by weight of V 2 O 5 .
Claim 3
Dependent Claim
34 words
The composition of claim 1 wherein the lead zirconate-lead titanate is Pb(Zr 0 .53 Ti 0 .47)O 3 and the V 2 O 5 content ranges from about 0.1 to about 1.5% by weight.
Claim 4
Dependent Claim
89 words
The composition of claim 1 prepared by the process of milling and blending a lead zirconate-lead titanate having the formula Pb(ZrTi)O 3 , wherein the Zr:Ti molar ratio ranges from about 65:35 to about 35:65, with from about 0.1 to about 6.0% by weight of a V 2 O 5 -affording promoter, pressing, and firing the blended powder in air at a temperature in the range of from about 860° to about 975° C. for a time sufficient to reach a density of at least 98% of theoretical density.
Claim 5
Dependent Claim
43 words
The composition of claim 3 wherein the lead zirconate-lead titanate is Pb(Zr 0 .53 Ti 0 .47)O 3 and the V 2 O 5 -affording promoter is V 2 O 5 utilized in amounts ranging from about 0.1 to about 1.5% by weight.
Claim 6
Dependent Claim
92 words
A process for preparing PZT ceramic compositions characterized by a density of at least 98% of theoretical density comprising the steps of milling and blending a lead zirconate-lead titanate powder having the formula Pb(ZrTi)O 3 , wherein the Zr:Ti molar ratio ranges from about 65:35 to about 35:65, with from about 0.1 to about 6.0% by weight of a V 2 O 5 -affording promoter, pressing, and firing the blended powder in air at a temperature of from about 860° to about 975° C. for from about 1 to about 120 minutes.
Claim 7
Dependent Claim
92 words
A process for preparing PZT ceramic compositions characterized by a density of at least 98% of theoretical density comprising the steps of milling and blending a lead zirconate-lead titanate powder having the formula Pb(ZrTi)O 3 , wherein the Zr:Ti molar ratio ranges from about 65:35 to about 35:65, with from about 0.1 to about 6.0% by weight of a V 2 O 5 -affording promoter, pressing, and firing the blended powder in air at a temperature of from about 860° to about 975° C. for from about 1 to about 120 minutes.
Claim 8
Dependent Claim
43 words
The process of claim 5 wherein the lead zirconate-lead titanate is Pb(Zr 0 .53 Ti 0 .47)O 3 and the V 2 O 5 -affording promoter is V 2 O 5 utilized in amounts ranging from about 0.1 to about 1.5% by weight.
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) | 1984-08-10 | 1985-02-09 | 1985-08-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-08-10 | 1989-02-09 | 1989-08-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-08-10 | 1993-02-09 | 1993-08-11 | $7700.00 | Window Closed / Lapsed |