US4284660A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electroless deposition process for zirconium and zirconium alloys
Assignee: General Electric Co
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Filing: 1978-05-11
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Granted: 1981-08-18
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Expires: 1998-05-11
Abstract
Abstract A method is disclosed for preventing stress corrosion cracking or metal embrittlement of a zirconium or zirconium alloy container that is to be coated on the inside surface with a layer of a metal such as copper, a copper alloy, nickel, or iron and used for holding nuclear fuel material as a nuclear fuel element. The zirconium material is etched in an etchant solution, desmutted mechanically or ultrasonically, oxidized to form an oxide coating on the zirconium, cleaned in an aqueous alkaline cleaning solution, activated for electroless deposition of a metal layer and contacted with an electroless metal plating solution. This method provides a boundary layer of zirconium oxide between the zirconium container and the metal layer.
Inventors
- 👤 Robert E. Donaghy
- 👤 Anna H. Sherman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 08:18
CPC Classifications
C; C23; C23C; C23C18/00; C23C18/16; C23C18/18; C23C18/1803; C23C18/1806; C23C18/1824; C23C18/1837; C23C18/1844
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
132 words
A method for producing a zirconium or a zirconium alloy container for fissionable nuclear reactor fuel, which container is resistant to stress corrosion cracking and embrittlement when subjected to fission reactions in nuclear reactor use, which method comprises the steps of: (a) etching the inside surface of said container, (b) desmutting the etched surface of said container to remove only loosely adhering material, (c) oxidizing the inside surface of said container with steam to produce a zirconium oxide coating thereon, (d) cleaning the oxidized surface of said container to remove substantially all foreign matter therefrom, (e) activating the oxidized surface of said container for electroless deposition of a metal layer thereon, and (f) contacting the activated surface of said container with an electroless metal plating solution to deposit a metal layer thereon.
Claim 2
Independent Claim
132 words
A method for producing a zirconium or a zirconium alloy container for fissionable nuclear reactor fuel, which container is resistant to stress corrosion cracking and embrittlement when subjected to fission reactions in nuclear reactor use, which method comprises the steps of: (a) etching the inside surface of said container, (b) desmutting the etched surface of said container to remove only loosely adhering material, (c) oxidizing the inside surface of said container with steam to produce a zirconium oxide coating thereon, (d) cleaning the oxidized surface of said container to remove substantially all foreign matter therefrom, (e) activating the oxidized surface of said container for electroless deposition of a metal layer thereon, and (f) contacting the activated surface of said container with an electroless metal plating solution to deposit a metal layer thereon.
Claim 3
Dependent Claim
27 words
A method according to claim 1 in which the zirconium oxide is electroless plated with a metal selected from the group consisting of copper, nickel and iron.
Claim 4
Dependent Claim
16 words
A method according to claim 2 in which the zirconium oxide is electroless plated with copper.
Claim 5
Dependent Claim
16 words
A method according to claim 2 in which the zirconium oxide is electroless plated with nickel.
Claim 6
Dependent Claim
15 words
A method according to claim 2 in which the zirconium is electroless plated with iron.
Claim 7
Dependent Claim
24 words
A method according to claim 1 where the inside surface of the container is etched by treating it with an ammonium bifluoridesulfuric acid solution.
Claim 8
Dependent Claim
28 words
A method according to claim 1 in which the oxidizing step is achieved by heating said container at elevated temperatures while the inside surface is contacted by steam.
Claim 9
Dependent Claim
26 words
A method according to claim 1 in which the desmutting step is achieved mechanically by contacting the inner surface of the container with a cotton swab.
Claim 10
Dependent Claim
29 words
A method according to claim 1 in which the desmutting step is achieved ultrasonically by immersing the container in a liquid followed by applying ultrasonic energy to the container.
Claim 11
Dependent Claim
13 words
A method according to claim 9 in which the liquid is deionized water.
Claim 12
Dependent Claim
28 words
A method according to claim 1 in which the cleaning step is achieved by contacting the inner surface of the container with an agitated aqueous alkaline cleaning solution.
Claim 13
Dependent Claim
19 words
A method according to claim 11 in which the agitation is achieved by impinging ultrasonic energy on the container.
Claim 14
Dependent Claim
28 words
A method according to claim 1 in which the activation step is achieved by contacting the inside surface of said container with an aqueous solution containing palladium chloride.
Claim 15
Dependent Claim
31 words
A method according to claim 1 in which the activation step is followed by contacting the inside surface of said container with an aqueous solution of fluoboric acid and oxalic acid.
Claim 16
Dependent Claim
28 words
A method according to claim 1 in which the activation step is achieved by contacting the inside surface of said container with an aqueous solution of stannous chloride.
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) | 1984-08-17 | 1985-02-16 | 1985-08-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-08-17 | 1989-02-16 | 1989-08-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-08-17 | 1993-02-16 | 1993-08-18 | $7700.00 | Window Closed / Lapsed |