US3678145A
Expired / Lapsed
US
⏱️ 0.0 years remaining
A method for preparing metal matrix composites containing modified polytetrafluoroethylene
Assignee: United States Department of the Air Force
•
Filing: 1969-12-23
•
Granted: 1972-07-18
•
Expires: 1989-12-23
Abstract
Abstract Polytetrafluoroethylene, sold under the trademark Teflon, is modified before being blended with metal powder and formed into a composite. Modification is accomplished by heating the Teflon for 1 to 2 hours at 1,000*-1,100*F and then for 3 to 3.5 hours at 650* to 750*F. Metal matrix composites containing modified Teflon as a filler are useful as retainer materials for bearings which are subjected to high temperature operating conditions.
Inventors
- 👤 David J Boes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 11:31
CPC Classifications
F; F16; F16D; F16D69/00; F16D69/02; C; C08; C08K; C08K3/00; C08K3/02; C08K3/08; C08K3/30; C22; C22C; C22C32/00; C22C32/0094
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
123 words
The method of manufacturing a self-lubricating composite article comprising the steps of: a. modifying polytetrafluoroethylene by heating it for about 1 to 2 hours at about 1,000* to 1,100*F and thereafter for about 3 to 3.5 hours at about 650* to 750*F; b. allowing the modified polytetrafluoroethylene to cool and thereafter grinding it into a powder; c. blending a mixture consisting of 20 volume percent of the modified polytetrafluoroethylene powder and 10 volume percent molybdenum diselenide powder with 70 volume percent of silver-mercury amalgam powder; and d. forming the blended powder mixture into said composite article by heating said mixture to a temperature of from 500* to 520*F for about 15 minutes while compressing said mixture under a pressure of about 50,000 psi.
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) | 1975-07-18 | 1976-01-17 | 1976-07-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-18 | 1980-01-17 | 1980-07-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-18 | 1984-01-17 | 1984-07-18 | $7700.00 | Window Closed / Lapsed |