Patent US3841870A successfully refreshed from Google Patents.
US3841870A
Expired / Lapsed
US
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Method of making articles from powdered material requiring forming at high temperature
Assignee: Carpenter Technology Corp
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Filing: 1973-03-07
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Granted: 1974-10-15
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Expires: 1993-03-07
Abstract
Abstract A pattern is made up of rigid and elastic material with the space between them forming a cavity in which powdered material is compacted by applying hydrostatic pressure to form a mold or part of a mold. The pattern is shaped so that the surface of the rigid material, which is dimensionally stable, forms a working surface of the mold formed in the cavity. Wood, plaster of paris, low melting metals, resins or wax is disclosed for use in forming the rigid portion of the pattern. The elastic material, which can be shaped from rubber or any suitable rubber-like material, facilitates forming the mold with a complex shape. The mold is then filled with powdered material and hot pressed to provide an object having a complex shape with a minimum of waste or expensive machining. Elemental nickel or iron or prealloyed powders are among the preferred powdered materials for making molds for hot pressing objects made of alloys that are difficult to form at high temperatures such as the superalloys. Molds formed from powdered aluminum are disclosed for hot pressing aluminum alloys. Molds made of powdered refractory metals, such as tungsten or molybdenum, are disclosed for hot pressing powdered refractory metals, carbides or ceramics.
Inventors
- 👤 H Hamjian
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 15:22
CPC Classifications
B; B22; B22F; B22F3/00; B22F3/12; B22F3/14; B22F3/1208; B22F3/1258; B22F3/1275
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
197 words
THE METHOD OF MAKING A DENSIFIED OBJECT FROM ETALLIC AND INORGANIC NONMETALLIC POWDERS AND COMBINATIONS THEREOF, SURFACE THEREOF HAVING A PREDETERMINED SHAPE, FORMING AT LEAST COMPRISING FORMING AT LEAST ONE RIGID PATTERN PORTION WITH A ONE READILY DEFORMABLE PATTERN PORTION HAVING A SURFACE COMPLEMENTARY TO BUT LARGER THAN SAID PREDETERMINED SHAPE, JOINING SAID RIGID AND DEFORMABLE PATTERN PORTIONS TO FORM A PATTERN DEFINING A MOLD-FORMING CAVITY BETWEEN THEM, FILLING SAID MOLD-FORMING CAVITY WITH MOLD-FORMING POWDERED METAL SELECTED FROM THE GROUP CONSISTING OF ELEMENTAL POWDERS, PREALLOYED METAL POWDERS AND COMBINATIONS THEREOF, COMPACTING SAID MOLD-FORMING POWDERED METAL BY APPLYING PRESSURE SUBSTANTIALLY INIFORMLY OVER SUBSTANTIALLY THE ENTIRE OUTER SURFACE OF SAID PATTERN TO FORM A GREEN COMPACT, STRENGTHERING SAID GREEN COMPACT TO FORM A MOLD, FILLING SAID MOLD WITH POWDERED MATERIAL SUITABLE FOR DENSIFICATION BY PRESSING AT A TEMPERATURE ABOVE THE SOFTENING TEMPERATURE OF SAID MOLD, HEATING SAID MOLD AND ITS CONTENTS TO A TEMPERATURE ABOVE THE SOFTENING POINT OF SAID MOLD, ISOSTATICALLY PRESSING SAID MOLD AT A PRESSURE HIGH ENOUGH TO EXCEED THE DEFORMATION STRENGTH OF SAID CONTENTS WHILE THUS HEATED TO DENSITY SAID CONTENTS AND FORM A DENSIFIED OBJECT, AND THEN REMOVING SAID MOLD FROM THE DENSIFIED OBJECT.
Claim 2
Independent Claim
197 words
THE METHOD OF MAKING A DENSIFIED OBJECT FROM ETALLIC AND INORGANIC NONMETALLIC POWDERS AND COMBINATIONS THEREOF, SURFACE THEREOF HAVING A PREDETERMINED SHAPE, FORMING AT LEAST COMPRISING FORMING AT LEAST ONE RIGID PATTERN PORTION WITH A ONE READILY DEFORMABLE PATTERN PORTION HAVING A SURFACE COMPLEMENTARY TO BUT LARGER THAN SAID PREDETERMINED SHAPE, JOINING SAID RIGID AND DEFORMABLE PATTERN PORTIONS TO FORM A PATTERN DEFINING A MOLD-FORMING CAVITY BETWEEN THEM, FILLING SAID MOLD-FORMING CAVITY WITH MOLD-FORMING POWDERED METAL SELECTED FROM THE GROUP CONSISTING OF ELEMENTAL POWDERS, PREALLOYED METAL POWDERS AND COMBINATIONS THEREOF, COMPACTING SAID MOLD-FORMING POWDERED METAL BY APPLYING PRESSURE SUBSTANTIALLY INIFORMLY OVER SUBSTANTIALLY THE ENTIRE OUTER SURFACE OF SAID PATTERN TO FORM A GREEN COMPACT, STRENGTHERING SAID GREEN COMPACT TO FORM A MOLD, FILLING SAID MOLD WITH POWDERED MATERIAL SUITABLE FOR DENSIFICATION BY PRESSING AT A TEMPERATURE ABOVE THE SOFTENING TEMPERATURE OF SAID MOLD, HEATING SAID MOLD AND ITS CONTENTS TO A TEMPERATURE ABOVE THE SOFTENING POINT OF SAID MOLD, ISOSTATICALLY PRESSING SAID MOLD AT A PRESSURE HIGH ENOUGH TO EXCEED THE DEFORMATION STRENGTH OF SAID CONTENTS WHILE THUS HEATED TO DENSITY SAID CONTENTS AND FORM A DENSIFIED OBJECT, AND THEN REMOVING SAID MOLD FROM THE DENSIFIED OBJECT.
Claim 3
Dependent Claim
17 words
The method as set forth in claim 1 wherein said rigid pattern portion is formed of wood.
Claim 4
Dependent Claim
19 words
The method as set forth in claim 1 wherein said rigid pattern portion is formed of plaster of paris.
Claim 5
Dependent Claim
20 words
The method as set forth in claim 1 wherein said rigid pattern portion is formed of a low melting material.
Claim 6
Dependent Claim
32 words
The method as set forth in claim 4 in which said low melting material is selected from the group consisting of metal and resin having a melting point below about 1,000* F.
Claim 7
Dependent Claim
21 words
The method as set forth in claim 1 wherein hydrostatic pressure is applied to said pattern to form the green compact.
Claim 8
Dependent Claim
32 words
The method as set forth in claim 6 wherein the powdered material used to fill said mold-forming cavity is selected from the group consisting of elemental metal powders, and prealloyed metal powders.
Claim 9
Dependent Claim
32 words
The method as set forth in claim 6 wherein the powdered material used to fill said mold-forming cavity is selected from the group consisting of powdered iron, nickel, aluminum, tungsten and molybdenum.
Claim 10
Dependent Claim
30 words
The method as set forth in claim 7 wherein said powdered material selected from the group consisting of elemental and prealloyed metal powders is slip cast in said mold-forming cavity.
Claim 11
Dependent Claim
18 words
The method as set forth in claim 1 wherein said green compact is sintered to form said mold.
Claim 12
Dependent Claim
48 words
The method as set forth in claim 1 wherein said mold is formed from powdered iron, the powdered material suitable for densification is a superalloy, and said isostatic pressing is carried out while said mold and its contents is at a temperature of about 2,000* to 2,200*F. F.
Claim 13
Dependent Claim
26 words
The method as set forth in claim 11 wherein said isostatic pressing is carried out at a pressure ranging from about 1,000 psi to 30,000 psi.
Claim 14
Dependent Claim
22 words
The method as set forth in claim 11 wherein said isostatic pressing is carried out at a pressure of about 15,000 psi.
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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) | 1977-10-14 | 1978-04-15 | 1978-10-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-14 | 1982-04-15 | 1982-10-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-14 | 1986-04-15 | 1986-10-15 | $7700.00 | Window Closed / Lapsed |