US3723109A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Extrusion of canned metal powders using graphite follower block
Assignee: Huntington Alloys Corp
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Filing: 1971-07-16
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Granted: 1973-03-27
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Expires: 1991-07-16
Abstract
Abstract In hot extruding a batch of dispersion-strengthened metal powder confined in a metal can through an extrusion die in which a uniformly high extrusion strain rate must be obtained, a graphite follower block of substantially the same diameter as the can is inserted between the end face of the extrusion ram and an end face of the heated can, the temperature of the block being at least substantially that of the canned powder, such that during extrusion, friction is markedly reduced by substantially inhibiting metal flashback from the can and the necessary high strain rate is obtained.
Inventors
- 👤 R Lacock
- 👤 J Benjamin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 10:29
CPC Classifications
B; B22; B22F; B22F3/00; B22F3/20; B21; B21C; B21C35/00; B21C35/04
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
238 words
In a powder metallurgy method of producing a wrought metal shape by hot extruding a batch of dispersion-strengthened metallic powder confined in a can made of metal which tends to become relatively soft at the extrusion temperature such that during extrusion metal flash-back from the can tends to occur between the extrusion ram and the extrusion cylinder which interferes with the extrusion efficiency by increasing extrusion friction, the improvement which comprises, providing a canned batch of mechanically alloyed composite metal powder of substantially saturated hardness formed of constituents which, when alloyed together, provide a dispersion-strengthened heat resistant alloy, inserting a hot graphite block of substantially the same diametral dimension as the canned powder between the end face of the ram and the end face of the canned powder at a temperature at least substantially that of the canned powder, and then hot extruding said canned batch of powder at a temperature of over about 1, 690*F. and at a reduction ratio of at least about 6.3 by force applied by the ram against the hot graphite block, whereby metal flash-back of the can is substantially inhibited and the friction of extrusion markedly reduced, said hot extrusion being carried out at a strain rate such that when the resulting hot extruded alloy is subsequently heated to an elevated germinative grain growth temperature, coarse grains are formed with a major axis disposed in the extrusion direction of the alloy shape.
Claim 2
Dependent Claim
119 words
The method of claim 2, wherein the hot extrusion is carried out at an extrusion ram speed at least as great as that determined by the formuLa: V/D K exp (-Q/RT)/1n phi - Etm ; where V ram speed in inches per second D billet diameter in inches phi extrusion ratio Q 65,000 calories per mole R gas constant T temperature in *K. K a constant ranging from 0.64 to 1010/sec. to 6.40 X 1010/sec. Etm a value ranging from 1.793 to 2.250 such that when the resulting hot worked alloy is subsequently heated to an elevated germinative grain growth temperature, coarse grains are formed with a major axis disposed in a principal working direction of the alloy shape.
Claim 3
Dependent Claim
32 words
The method of claim 2, wherein the hot extrusion is carried out at a temperature selected from the range of 1,775* to 2, 100*F. and a reduction ratio between 8.5 and 25.
Claim 4
Dependent Claim
151 words
The method of claim 2, wherein the dispersion-strengthened heat resistant alloy has a composition ranging by weight from about 5 to 60 percent chromium, about 0.5 to 6.5 percent aluminum, about 0.5 to 6.5 percent titanium, up to about 15 percent molybdenum, up to about 20 percent tungsten, up to about 10 percent columbium, up to about 10 percent tantalum, up to about 3 percent vanadium, up to about 2 percent manganese, up to about 2 percent silicon, up to about 0.75 percent carbon, up to about 0.1 percent boron, up to about 1 percent zirconium, up to about 0.2 percent magnesium, up to about 6 percent hafnium, up to about 35 percent iron, about 0.5 to 10 percent by volume of a refractory dispersoid, and the balance essentially a metal from the group consisting of nickel and cobalt in an amount at least about 40 percent of the total composition.
Claim 5
Dependent Claim
124 words
The method of claim 5, wherein the composition ranges from about 15 to 35 percent chromium, about 0.5 to 2.5 percent aluminum, about 1 to 5 percent titanium, up to about 5 percent molybdenum, up to about 5 percent tungsten, up to about 2 percent columbium, up to about 4 percent tantalum, up to about 1 percent vanadium, up to about 2 percent manganese, up to about 1 percent silicon, up to about 0.2 percent carbon, up to about 0.1 percent boron, up to about 0.5 percent zirconium, up to 0.2 percent magnesium, up to 2 percent hafnium, up to about 10 percent iron, about 0.5 volume percent to 5 volume percent of a dispersoid, the balance essentially at least about 40 percent nickel.
Claim 6
Dependent Claim
18 words
The method of claim 6, wherein the chromium content of the alloy does not exceed about 25 percent.
Claim 7
Dependent Claim
32 words
The method of claim 7, wherein the alloy following hot working is heated to its germinative grain growth temperature to form coarse elongated grains disposed in the working direction of the alloy.
Claim 8
Dependent Claim
25 words
The method of claim 1 in which the metal of the can is selected from the group consisting of mild steel, stainless steel and nickel.
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) | 1976-03-26 | 1976-09-25 | 1977-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-26 | 1980-09-25 | 1981-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-26 | 1984-09-25 | 1985-03-27 | $7700.00 | Window Closed / Lapsed |