Marlene Grace Wartenberg¹, Junsoo Han¹, Peter Hosemann², Nan Li³, John Scully¹; ¹University of Virginia, ²University of California, Berkeley, ³Los Alamos National Laboratory

This research seeks to develop a better understanding of the effects of various “harsh” environments on the passive preformed-oxide developed on model structural materials. Systematic studies were conducted on a range of model Fe-Cr and Ni-Cr alloy systems after passivation in aqueous solutions or by thermal “pre-oxidation in air”. The samples were subsequently exposed to various aqueous solutions and room temperature ionic liquids with various salt species in isolation. These may alter or dissolve the preformed-oxide film and ultimately govern the corrosion behavior. The sample was also tested in classes of ionic liquids and molten salts, with and without radiation. EIS was used to first characterize the preformed-oxide. Capacitance and Mott-Schottky plots were utilized in order to quantify film thickness, oxide dissolution rates versus time, semiconductor dopant type, electronic defect type, and densities. Altered oxides and intact oxides were compared and contrasted after investigation by XPS, SIMS and FIB-TEM.