US5015440A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Refractory aluminides
Assignee: McDonnell Douglas Corp
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Filing: 1989-09-01
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Granted: 1991-05-14
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Expires: 2009-09-01
Abstract
Abstract Light weight refractory aluminides, such as Al 3 Nb and related aluminides may be produced from metallic powders by a high temperature exothermic reaction of refractory metals with molten aluminum. Mixtures of refractory metals and aluminum may be prepared and densified by powder metalurgy techniques. Applicant's process permits near net formations of stock shapes and parts by conducting the reaction in situ in a die.
Inventors
- 👤 David M. Bowden
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 01:15
CPC Classifications
C; C22; C22C; C22C1/00; C22C1/04; C22C1/047
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
100 words
A method of producing refractory aluminides comprising combining a powdered refractory metal and powdered aluminum in reactive proportions, confining the combined metal powders and heating the combined metal powders to remove entrained gases and moisture, exposing the combined metal powders to a vacuum and sealing the combined metal powders under the vacuum, applying pressure to the sealed confined metal powders and heating the confined metal powders to a temperature above the melting point of aluminum, the temperature being effective to initiate and sustain a reaction between the refractory metal and the aluminum substantially to completion, and recovering the refractorY aluminide.
Claim 2
Independent Claim
100 words
A method of producing refractory aluminides comprising combining a powdered refractory metal and powdered aluminum in reactive proportions, confining the combined metal powders and heating the combined metal powders to remove entrained gases and moisture, exposing the combined metal powders to a vacuum and sealing the combined metal powders under the vacuum, applying pressure to the sealed confined metal powders and heating the confined metal powders to a temperature above the melting point of aluminum, the temperature being effective to initiate and sustain a reaction between the refractory metal and the aluminum substantially to completion, and recovering the refractorY aluminide.
Claim 3
Dependent Claim
24 words
The method of claim 1 including heating the recovered refractory aluminide under temperatures and at pressures effective to substantially fully densify the refractory aluminide.
Claim 4
Dependent Claim
20 words
The method of claim 1 wherein the refractory metal is selected from the group consisting of niobium, tungsten and tantalum.
Claim 5
Dependent Claim
11 words
The method of claim 1 wherein the refractory metal is niobium.
Claim 6
Dependent Claim
17 words
The method of claim 4 wherein the mixed metal powders are heated to between about 800°-1200° C.
Claim 7
Dependent Claim
24 words
The method of claim 4 wherein the refractory aluminide is densified at about 1400° C., under about 200 MPa pressure for about 4 hours.
Claim 8
Dependent Claim
16 words
The method of claim 4 wherein the mixed metal powders are confined in a niobium container.
Claim 9
Dependent Claim
15 words
The method of claim 1 wherein the refractory aluminide is formed as a shaped part.
Claim 10
Dependent Claim
15 words
The method of claim 1 wherein the refractory aluminide is formed as a stock shape.
Claim 11
Dependent Claim
15 words
The process of claim 1 wherein the composition of the mixture contains other metallic elements.
References Cited (Backward Citations)
US4762558A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-05-13 | 1994-11-12 | 1995-05-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-05-13 | 1998-11-12 | 1999-05-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-05-13 | 2002-11-12 | 2003-05-14 | $7700.00 | Window Closed / Lapsed |