Patent US4142023A successfully refreshed from Google Patents.
US4142023A
Expired / Lapsed
US
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Method for forming a single-phase nickel aluminide coating on a nickel-base superalloy substrate
Assignee: RTX Corp
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Filing: 1977-08-24
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Granted: 1979-02-27
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Expires: 1997-08-24
Abstract
Abstract A method for coating a nickel-base superalloy substrate with a nickel-aluminide coating, saturated with chromium and containing no precipitated phases is disclosed which comprises enriching the superalloy substrate with chromium by diffusion of chromium into the substrate at a rate below that at which a pure or alloyed chromium layer forms and then growing a nickel aluminide coating on the chromium enriched substrate surface by the outward diffusion of nickel from the substrate into an aluminum-containing pack in which the source of aluminum is the stoichiometric intermetallic compound NiAl, or a metal powder mixture having the overall aluminum activity of NiAl.
Inventors
- 👤 Norman S. Bornstein
- 👤 Michael A. DeCrescente
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 02:39
CPC Classifications
C; C23; C23C; C23C10/00; C23C10/28; C23C10/34; C23C10/58; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12771; Y10T428/12861; Y10T428/12944
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
148 words
A process for forming on a nickel-base superalloy substrate, a single-phase nickel aluminide coating containing chromium which comprises: (a) enriching the surface of said nickel-base superalloy substrate with a face centered cubic solution of chromium in nickel, said substrate remaining substantially free from a body-centered cubic coating of chromium or a chromium-base alloy; by diffusing chromium into said substrate from a source of chromium comprising a mixture of nickel and chromium in which the amount of chromium does not exceed the amount of chromium which would be soluble in the nickel; and (b) forming a nickel-aluminide coating on the chromium enriched substrate by causing nickel to diffuse outwardly from said substrate into an aluminum-containing pack in which the source of aluminum is a material selected from the group consisting of the intermetallic compound NiAl and a metal powder pack having the overall activity of aluminum associated with NiAl.
Claim 2
Dependent Claim
148 words
A process for forming on a nickel-base superalloy substrate, a single-phase nickel aluminide coating containing chromium which comprises: (a) enriching the surface of said nickel-base superalloy substrate with a face centered cubic solution of chromium in nickel, said substrate remaining substantially free from a body-centered cubic coating of chromium or a chromium-base alloy; by diffusing chromium into said substrate from a source of chromium comprising a mixture of nickel and chromium in which the amount of chromium does not exceed the amount of chromium which would be soluble in the nickel; and (b) forming a nickel-aluminide coating on the chromium enriched substrate by causing nickel to diffuse outwardly from said substrate into an aluminum-containing pack in which the source of aluminum is a material selected from the group consisting of the intermetallic compound NiAl and a metal powder pack having the overall activity of aluminum associated with NiAl.
Claim 3
Dependent Claim
28 words
The process of claim 1 in which the amount of chromium in the nickel-chromium source of chromium is less than about 40% by weight of the nickel-chromium source.
Claim 4
Dependent Claim
12 words
The process of claim 1 wherein the source of aluminum is NiAl.
Claim 5
Dependent Claim
19 words
The process of claim 1 wherein the source of aluminum is a uniform mixture of nickel and aluminum powders.
Claim 6
Dependent Claim
27 words
The process of claim 1 wherein the source of aluminum is in the form of a core of aluminum powder surrounded by a jacket of nickel powder.
Claim 7
Dependent Claim
28 words
The process of claim 3 in which the amount of chromium in the nickel-chromium source of chromium is less than about 40% by weight of the nickel-chromium source.
Claim 8
Dependent Claim
28 words
The process of claim 4 in which the amount of chromium in the nickel-chromium source of chromium is less than about 40% by weight of the nickel-chromium source.
Claim 9
Dependent Claim
28 words
The process of claim 5 in which the amount of chromium in the nickel-chromium source of chromium is less than about 40% by weight of the nickel-chromium source.
Claim 10
Dependent Claim
22 words
The nickel based superalloy having a single phase chromium containing nickel aluminide coating product produced according to the process of claim 1.
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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) | 1982-02-26 | 1982-08-28 | 1983-02-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-02-26 | 1986-08-28 | 1987-02-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-02-26 | 1990-08-28 | 1991-02-27 | $7700.00 | Window Closed / Lapsed |