Process for manufacturing high density press-formed articles
Abstract
Abstract HIGH DENSITY PRESS-FORMED ARTICLES MAY BE FORMED FROM A POWDER MIXTURE, CONSISTING PREDOMINANTLY OF HIGH ALLOY METALS, WHICH CAN BE FORGED ONLY WITH DIFFICULTY, IF AT ALL. A PREPRESSED WORKPIECE IS FORMED FROM THE POWDER MIXTURE AT A PRESSURE OF ABOUT 6 T./CM.2, AND IS THEN HEATED TO BETWEEN 800 AND 1100*C. THE HEATED WORKPIECE IS THEN COMPACTED OR DEFORMED AT A PRESSURE OF ABOUT 8 T./CM.2 IN A PRESS TOOL WHICH HAS BEEN PREHEATED TO A TEMPERATURE BETWEEN 150 AND 350*C. AND WHICH IS HELD CONSTANT AT THIS TEMPERATURE DURING THE COMPACTING OPERATION. THERE IS NO SINTERING OF THE WORKPIECE IN THE PRESS TOOL. THE RESULTANT PRESS-FORMED ARTICLE MAY THEN BE ANNEALED IN A VACUUM FOR 4 TO 5 HOURS AT 1250*C.
Inventors
- 👤 Gerhard Zapf
Bibliographic Details
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-09-19 | 1975-03-21 | 1975-09-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-19 | 1979-03-21 | 1979-09-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-19 | 1983-03-21 | 1983-09-20 | $7700.00 | Window Closed / Lapsed |