Aqueous Corrosion Behavior of Ce Alloys and an Assessment of Their Adequacy as Surrogates for Pu Alloys

Abstract

The corrosion behavior of Ce metal and a Ga alloy in aqueous deaerated solutions has been investigated through potentiodynamic and electrochemical impedance experiments. The solutions consist of concentrations of HCl, NaCl, , , , and . It was found that the addition of Ga is generally detrimental to the corrosion resistance of Ce, resulting in the loss of passivity and a decrease in polarization resistance. Ce metal was found to be susceptible to pitting in chloride environments. Increasing acidity was found to promote the passivity of Ce in chloride and sulfate solutions. The opposite was true in nitrate solutions. Dissolution of the Ce–Ga alloy was ohmically limited in certain solutions. The ohmic limitation was not attributable to the solution resistance. Although the addition of Ga was found to be detrimental to the corrosion resistance of Ce and Pu, Ce and Ce–Ga were found to be poor electrochemical surrogates for Pu and Pu–Ga.