Patent US4008052A successfully refreshed from Google Patents.
US4008052A
Expired / Lapsed
US
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Method for improving metallurgical bond in bimetallic castings
Assignee: Northrop Grumman Space and Mission Systems Corp
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Filing: 1975-04-30
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Granted: 1977-02-15
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Expires: 1995-04-30
Abstract
Abstract Method for making a bicast article in which a solid metal preform is positioned in a mold and a molten metal is cast around portions of the preform which are exposed in the mold. In accordance with the present invention, the exposed portions are coated prior to the casting step with a boron containing alloy which is compatible with the preform and with the metal to be cast about it, the boron containing alloy having a melting range below the melting range of either the preform or the cast metal. The alloy also has a major ingredient which is the same as the major ingredient of at least one of the metals to be joined. After solidification of the molten metal in the casting cavity, the resulting bicast article is heat treated at a temperature below the melting range of either the preform or the solidified metal to cause diffusion of boron into the preform and into the solidified metal thereby providing an improved metallurgical bond.
Inventors
- 👤 Constantine Vishnevsky
- 👤 Lawrence D. Graham
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 09:40
CPC Classifications
B; B23; B23K; B23K37/00; B23K37/06; B22; B22D; B22D19/00; B22D19/04; Y; Y10; Y10S; Y10S428/00; Y10S428/922; Y10S428/9335; Y10S428/941; Y10T; Y10T428/00; Y10T428/12; Y10T428/12458; Y10T428/12472; Y10T428/12493; Y10T428/12771; Y10T428/12861; Y10T428/12944
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
145 words
In the method of making a bicast article in which a solid metal preform is positioned in a mold and a molten metal is cast about the portions of said preform exposed in said mold, the improvement which comprises coating said exposed portions prior to the casting step with a boron containing alloy having a melting range below the melting range of either said preform or said cast metal, fusing said alloy into said preform without significant interalloying with the metal preform, said alloy having a major ingredient the same as the major ingredient of at least one of the metals to be joined, and heat treating the resulting bicast article after solidification of the molten metal at a temperature below the melting range of either said preform or the solidified metal to cause diffusion of boron into the preform and into the solidified metal.
Claim 2
Dependent Claim
145 words
In the method of making a bicast article in which a solid metal preform is positioned in a mold and a molten metal is cast about the portions of said preform exposed in said mold, the improvement which comprises coating said exposed portions prior to the casting step with a boron containing alloy having a melting range below the melting range of either said preform or said cast metal, fusing said alloy into said preform without significant interalloying with the metal preform, said alloy having a major ingredient the same as the major ingredient of at least one of the metals to be joined, and heat treating the resulting bicast article after solidification of the molten metal at a temperature below the melting range of either said preform or the solidified metal to cause diffusion of boron into the preform and into the solidified metal.
Claim 3
Dependent Claim
13 words
The method of claim 1 in which said preform has anisotropic metallurgical properties.
Claim 4
Dependent Claim
14 words
The method of claim 1 in which said preform has an elongated grain structure.
Claim 5
Dependent Claim
20 words
The method of claim 1 in which said preform consists of a directionally solidified casting having a columnar grained structure.
Claim 6
Dependent Claim
18 words
The method of claim 1 in which said preform is a directionally solidified casting of substantially eutectic composition.
Claim 7
Dependent Claim
19 words
The method of claim 1 in which said preform consists of a composite having a fiber reinforced metal matrix.
Claim 8
Dependent Claim
15 words
The method of claim 1 in which said preform is substantially of an airfoil geometry.
Claim 9
Dependent Claim
16 words
The method of claim 1 in which said preform is composed of a nickel base superalloy.
Claim 10
Dependent Claim
16 words
The method of claim 1 in which said preform is composed of a cobalt base superalloy.
Claim 11
Dependent Claim
16 words
The method of claim 1 in which said boron containing alloy is a nickel base alloy.
Claim 12
Dependent Claim
24 words
The method of claim 1 in which said heat treatment is carried out at a temperature in the range from 1850° to 2250° F.
Claim 13
Dependent Claim
19 words
The method of claim 1 in which said boron containing alloy contains between 1 and 4% by weight boron.
Claim 14
Dependent Claim
30 words
The method of claim 1 in which said boron containing alloy contains from 5 to 25% chromium, 1 to 4% boron, 0.05 to 0.2% carbon, and the balance substantially nickel.
Claim 15
Dependent Claim
69 words
A composite metallic article comprising a first nickel base superalloy bonded to a second nickel base superalloy through an intermediate bonding zone of a nickel base alloy containing boron, both said first and second nickel base superalloys having boron diffused therein from said bonding zone, and the interface between said first and second superalloys with said bonding zone being characterized by small columnar grains extending perpendicular to said interface.
Claim 16
Dependent Claim
69 words
A composite metallic article comprising a first nickel base superalloy bonded to a second nickel base superalloy through an intermediate bonding zone of a nickel base alloy containing boron, both said first and second nickel base superalloys having boron diffused therein from said bonding zone, and the interface between said first and second superalloys with said bonding zone being characterized by small columnar grains extending perpendicular to said interface.
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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) | 1980-02-15 | 1980-08-16 | 1981-02-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-02-15 | 1984-08-16 | 1985-02-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-02-15 | 1988-08-16 | 1989-02-15 | $7700.00 | Window Closed / Lapsed |