9357463 Scully Factors controlling the passivity and corrosion of intermetallic compounds in aqueous solutions are examined using nickel aluminides and titanium aluminides as model systems. A parallel investigation is pursued on intergranular separation in polycrystalline metallic materials using bond percolation theory. Model materials are available from industry and also can be prepared by rapid solidification, co-sputter deposition, or ion implantation. Structure and composition are characterized by scanning electron microscopy and X-ray diffraction and electrochemical properties characterized by several techniques, including AC and DC electrochemistry and solution analysis. %%% Corrosion and passivity mechanisms are unclarified for emerging structural intermetallic materials proposed for structural applications as well as those formed in microelectronic processing. This research should clarify these mechanisms and lead to procedures for predicting electrochemical properties. ***
