Electroless deposition process for zirconium and zirconium alloys
AssigneeGeneral Electric Company
InventorsRobert E. Donaghy, Anna H. Sherman
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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.
Claims15
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.
Dependencies are inferred from the claim text.