Patent US4764492A successfully refreshed from Google Patents.
US4764492A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Lead calcium titanate piezoelectric ceramic element
Assignee: Philips North America LLC
•
Filing: 1986-06-10
•
Granted: 1988-08-16
•
Expires: 2006-06-10
Abstract
Abstract An improved lead calcium titanate piezoelectric sintered body is produced by sintering in air at 1000 DEG C.-1200 DEG C. a calcined mixture of oxides or oxide compounds in amounts adapted to form a composition of the formula Pb1-xCaxTi1-y(Co1/2W1/2)yO3+0.005-0.02(A) where A is at least one of MnO, MnO2, NiO and Nb2O3, wherein x=0.3-0.4 and 0.04<y</=0.06.
Inventors
- 👤 Kiyoshi Takeuchi
- 👤 Dragan Damjanovic
- 👤 Sei-Joo Jang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 07:10
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/46; C04B35/462; C04B35/472; H; H10; H10N; H10N30/00; H10N30/01; H10N30/09; H10N30/093; H10N30/097; H10N30/80; H10N30/85; H10N30/853; H10N30/8548
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
169 words
A method of producing a sintered piezoelectric body having a composition of the formula Pb 1-x Ca x Ti 1-y (Co 1/2 W 1/2 ) y O 3 +0.005-0.02(A) wherein A is a member selected from the group consisting of MnO, MnO 2 , NiO and Nb 2 O 3 and mixtures thereof, wherein x=0.3-0.4 and 0.04<y≦0.06 said piezoelectric body having a high thickness coupling factor k t , a low planar coupling factor k p , a high dielectric constant K, a high piezoelectric constant d 33 and a low dissipation factor D, said method comprising: (a) calcining a ground mixture of the oxides PbO, CaO, TiO, Co(OH) 2 , WO 3 and at least one of MnO or MnO 2 or of the precursors of said oxides in amounts adapted to form said composition and sintering the resultant calcined mixture in an atmosphere consisting essentially of 10-20% of oxygen and 90-80% of nitrogen at a temperature of 1000° C.-1200° C. for a period of 5 hours-30 hours.
Claim 2
Independent Claim
169 words
A method of producing a sintered piezoelectric body having a composition of the formula Pb 1-x Ca x Ti 1-y (Co 1/2 W 1/2 ) y O 3 +0.005-0.02(A) wherein A is a member selected from the group consisting of MnO, MnO 2 , NiO and Nb 2 O 3 and mixtures thereof, wherein x=0.3-0.4 and 0.04<y≦0.06 said piezoelectric body having a high thickness coupling factor k t , a low planar coupling factor k p , a high dielectric constant K, a high piezoelectric constant d 33 and a low dissipation factor D, said method comprising: (a) calcining a ground mixture of the oxides PbO, CaO, TiO, Co(OH) 2 , WO 3 and at least one of MnO or MnO 2 or of the precursors of said oxides in amounts adapted to form said composition and sintering the resultant calcined mixture in an atmosphere consisting essentially of 10-20% of oxygen and 90-80% of nitrogen at a temperature of 1000° C.-1200° C. for a period of 5 hours-30 hours.
Claim 3
Dependent Claim
26 words
The method of claim 1 wherein the sintering is carried out in air at a temperature of 1100°-1150° C. for a period of 5 hours-30 hours.
Claim 4
Dependent Claim
19 words
The method of claim 2 wherein the calcination is carried out at a temperature of about 925° C.-975° C.
Claim 5
Dependent Claim
11 words
A sintered piezoelectric body produced by the method of claim 1.
Claim 6
Dependent Claim
11 words
A sintered piezoelectric body produced by the method of claim 2.
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) | 1991-08-16 | 1992-02-15 | 1992-08-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-08-16 | 1996-02-15 | 1996-08-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-08-16 | 2000-02-15 | 2000-08-16 | $7700.00 | Window Closed / Lapsed |