US4379719A
Expired / Lapsed
US
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Aluminum powder alloy product for high temperature application
Assignee: Alcoa Corp
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Filing: 1981-11-20
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Granted: 1983-04-12
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Expires: 2001-11-20
Abstract
Abstract Aluminum alloy atomized powder containing 4 to 12% iron and 1 to 7% cerium or other rare earth metal, when properly compacted and shaped into a useful article, exhibits very high strength at relatively high temperatures. The iron content exceeds the cerium or rare earth metal content, and the powder may contain refractory elements such as W, Mo and others. The powder is produced by atomizing alloyed molten aluminum, preferably in a nonoxidizing atmosphere, and is compacted to a density approaching 100% under controlled conditions including controlled temperature conditions. The alloy may be subsequently shaped by conventional forging, extruding or rolling processes.
Inventors
- 👤 Gregory J. Hildeman
- 👤 Robert E. Sanders, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 05:45
CPC Classifications
B; B22; B22F; B22F3/00; B22F3/12; B22F3/16
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
97 words
A method of producing an improved aluminum article having high strength at elevated temperatures, comprising the steps: (a) providing aluminum alloy particulate consisting essentially of 4 to 12% iron, 1 to 7% rare earth metal, balance aluminum and impurities and incidental elements, the weight ratio of iron to rare earth metal falling within the range of 1.2 to 4.4:1; and (b) compacting said powder under vacuum at a pressure of one torr or less and elevated temperature conditions wherein said powders are compacted to at least 95% of full density at a temperature greater than 650° F.
Claim 2
Independent Claim
97 words
A method of producing an improved aluminum article having high strength at elevated temperatures, comprising the steps: (a) providing aluminum alloy particulate consisting essentially of 4 to 12% iron, 1 to 7% rare earth metal, balance aluminum and impurities and incidental elements, the weight ratio of iron to rare earth metal falling within the range of 1.2 to 4.4:1; and (b) compacting said powder under vacuum at a pressure of one torr or less and elevated temperature conditions wherein said powders are compacted to at least 95% of full density at a temperature greater than 650° F.
Claim 3
Dependent Claim
22 words
The improvement according to claim 1 wherein the rare earth metal is selected from the group consisting of cerium and misch metal.
Claim 4
Dependent Claim
23 words
The improvement according to claim 1 wherein the aluminum alloy contains from 6 to 10% iron and 2 to 6% rare earth elements.
Claim 5
Dependent Claim
22 words
The improvement according to claim 3 wherein the rare earth metal is selected from the group consisting of cerium and misch metal.
Claim 6
Dependent Claim
32 words
The improvement according to claim 1 wherein said particulate additionally contains one or more of up to 2.5% tungsten, up to 2.5% tantalum, up to 1.5% molybdenum and up to 1.5% niobium.
Claim 7
Dependent Claim
32 words
The improvement according to claim 4 wherein said particulate additionally contains one or more of up to 2.5% tungsten, up to 2.5% tantalum, up to 1.5% molybdenum and up to 1.5% niobium.
Claim 8
Dependent Claim
17 words
The improvement according to claim 6 wherein the total of said additional elements does not exceed 5%.
Claim 9
Dependent Claim
20 words
The improvement according to claim 1 wherein said particulate is produced by atomizing a superheated melt in a nonoxidizing atmosphere.
Claim 10
Dependent Claim
13 words
The improvement according to claim 8 wherein said nonoxidizing atmosphere is flue gas.
Claim 11
Dependent Claim
34 words
The improvement according to claim 1 wherein, prior to said vacuum compaction at elevated temperature, said particulate is isostatically compacted at room temperature to a cohesive shape exhibiting at least 65% of full density.
Claim 12
Dependent Claim
20 words
The improvement according to claim 1 wherein said vacuum compaction is effected at a temperature of at least 700° F.
Claim 13
Dependent Claim
22 words
The improvement according to claim 1 wherein said compaction is effected at a temperature in the range of 700° to 850° F.
Claim 14
Dependent Claim
22 words
The improvement according to claim 4 wherein said compaction is effected at a temperature in the range of 700° to 800° F.
Claim 15
Dependent Claim
16 words
The improvement according to claim 4 wherein said aluminum particulate contains less than 0.6% aluminum oxide.
Claim 16
Dependent Claim
13 words
The improvement according to claim 1 wherein said aluminum particulate is atomized powder.
Claim 17
Dependent Claim
25 words
The improvement according to claim 1 wherein substantially concurrently with said vacuum compaction the compact is upset equivalent to a reduction of at least 25%.
Claim 18
Dependent Claim
35 words
The method according to claim 1 wherein subsequent to said vacuum compaction the compact is worked equivalent to a reduction of at least 25% at a temperature within the range of 550° to 850° F.
Claim 19
Dependent Claim
42 words
The improvement according to claim 1 wherein said improved article exhibits high strength at elevated temperatures characterized by a yield strength of at least 30,000 psi and elongation of at least 5% at 450° F. after 1000 hours exposure to said temperature.
Claim 20
Dependent Claim
42 words
The improvement according to claim 1 wherein said improved article exhibits high strength at elevated temperatures characterized by a yield strength of at least 35,000 psi and elongation of at least 51/2% at 450° F. after 1000 hours exposure to said temperature.
Claim 21
Independent Claim
150 words
A method of producing an improved aluminum article having high strength at elevated temperatures, comprising the steps: (a) providing atomized aluminum alloy powder consisting essentially of 4 to 12% iron, 1 to 7% of at least one metal from the group consisting of cerium and misch metal, balance aluminum and impurities and incidental elements, the weight ratio of iron to cerium plus misch metal ranging between 1.2 and 4.4:1; (b) vacuum compacting said powder at a pressure not exceeding 0.1 torr and a temperature of 700° to 850° F. under sufficient compaction to produce a compact at least 98% of full density; and (c) working said compact at a temperature of 550° to 850° F. equivalent to a cross-sectional reduction of at least 25% to produce said article characterized by a yield strength of at least 35,000 psi and elongation of at least 51/2% at a temperature of 450° F.
Claim 22
Independent Claim
150 words
A method of producing an improved aluminum article having high strength at elevated temperatures, comprising the steps: (a) providing atomized aluminum alloy powder consisting essentially of 4 to 12% iron, 1 to 7% of at least one metal from the group consisting of cerium and misch metal, balance aluminum and impurities and incidental elements, the weight ratio of iron to cerium plus misch metal ranging between 1.2 and 4.4:1; (b) vacuum compacting said powder at a pressure not exceeding 0.1 torr and a temperature of 700° to 850° F. under sufficient compaction to produce a compact at least 98% of full density; and (c) working said compact at a temperature of 550° to 850° F. equivalent to a cross-sectional reduction of at least 25% to produce said article characterized by a yield strength of at least 35,000 psi and elongation of at least 51/2% at a temperature of 450° F.
Claim 23
Dependent Claim
47 words
The improvement according to claim 20 wherein said aluminum alloy powder additionally contains one or more of the group of up to 2.5% tungsten, up to 2.5% tantalum, up to 1.5% molybdenum and up to 1.5% niobium, the combined total of said additional elements not exceeding 5%.
Claim 24
Dependent Claim
54 words
The improvement according to claim 20 wherein, prior to said compaction, said powder is isostatically compacted at room temperature to a cohesive shape exhibiting at least 65% of full density which said isostatically compacted cohesive shape is then compacted at said elevated temperature and vacuum condition according to said step (b) of claim 20.
Claim 25
Dependent Claim
25 words
The improvement according to claim 20 wherein said working of said step (c) is equivalent to a reduction of at least 50% in cross section.
Claim 26
Dependent Claim
10 words
The aluminum article produced by the method of claim 1.
Claim 27
Dependent Claim
10 words
The aluminum article produced by the method of claim 5.
Claim 28
Dependent Claim
10 words
The aluminum article produced by the method of claim 6.
Claim 29
Dependent Claim
10 words
The aluminum article produced by the method of claim 12.
Claim 30
Dependent Claim
10 words
The aluminum article produced by the method of claim 17.
Claim 31
Dependent Claim
10 words
The aluminum article produced by the method of claim 20.
Claim 32
Dependent Claim
10 words
The aluminum article produced by the method of claim 21.
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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) | 1986-04-11 | 1986-10-11 | 1987-04-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-04-11 | 1990-10-11 | 1991-04-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-04-11 | 1994-10-11 | 1995-04-12 | $7700.00 | Window Closed / Lapsed |