Preparation of Uranium for Electroplating with Nickel

Abstract

SummaryA process was developed for reliably protecting unalloyed depleted uranium with an adherent, corrosion-resistant electroplated deposit. The key to the process was treatment of the uranium with a metal chloride/nitric acid solution before plating. Solutions containing stannous or nickel chloride yielded results superior to those of solutions containing other metal chlorides. For production purposes, however, the nickel chloride solution—because it could be operated at a lower temperature, removed less metal, and was more stable—was preferable to the stannous chloride solution. Plated parts that had been pretreated in any of the metal chloride solutions investigated were capable of withstanding exposure to a water-saturated atmosphere at 200°F for at least 90 h without showing signs of deterioration. Plated parts pretreated in the stannous chloride solution showed no signs of deterioration after five years of outdoor exposure at Livermore, Calif. A significant additional discovery was that the use of an alkaline immersion cleaning cycle before and after pretreatment noticeably improved the corrosion resistance of plated parts, not only when the metal chloride/nitric acid solution was used, but especially when other, inferior pretreating solutions were used.