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AssigneeThe United States of America as represented by the United States Department of Energy
InventorsForrest B. Waldrop, Charles A. Washington
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Uranium articles are provided with anodized oxide coatings in an aqueous solution of an electrolyte selected from the group consisting of potassium phosphate, potassium hydroxide, ammonium hydroxide, and a mixture of potassium tetraborate and boric acid. The uranium articles are anodized at a temperature greater than about 75.degree. C. with a current flow of less than about 0.036 A/cm.sup.2 of surface area while the pH of the solution is maintained in a range of about 2 to 11.5. The pH values of the aqueous solution and the low current density utilized during the electrolysis prevent excessive dissolution of the uranium and porosity in the film or watering. The relatively high temperature of the electrolyte bath inhibits hydration and the attendant deleterious pitting so as to enhance corrosion resistance of the anodized coating.
A method for providing a uranium article with a corrosion-resistant anodized oxide coating comprising the steps of providing an aqueous solution of electrolytes selected from the group consisting of potassium phosphate, potassium hydroxide, ammonium hydroxide, and a mixture of potassium tetraborate and boric acid, maintaining the solution at a pH value in the range of about 2 to 11.5 and at a temperature of at least 75.degree. C., immersing the uranium article into the electrolyte and maintaining a current density of less than about 0.036 A/cm.sup.2 between electrodes for a duration sufficient to provide an equilibrium in the thickness of the oxide coating.
Dependencies are inferred from the claim text.