Characterization and corrosion stability of SiC coatings using ion beam analysis techniques

Thin SiC films (thickness ca. 200-300 nm) were prepared by ion sputtering on the surface of Ti-Al-V alloy (TA6V) at room temperature and at 750 degrees C. Part of the films was additionally subjected to dynamic ion mixing (DIM) during the deposition procedure. The coated samples were electrochemically treated to 0.9% NaCl (37 degrees C) in order to investigate their pitting corrosion resistance. The determination of the silicon, carbon and oxygen depth distribution before and after the corrosion attack was performed by proton Rutherford backscattering spectrometry (p-RBS) and by using the resonances at 4.265 and 3.035 MeV of the C-12(alpha, alpha)C-12 and O-16(alpha, alpha)O-16 interactions, respectively. The ratio of Si:C was found to be close to the stoichiometric one. The coatings prepared at room temperature exhibited remarkable resistance to pitting corrosion. The surface morphology of the samples was also investigated by scanning electron microscopy (SEM/EDS). (c) 2005 Elsevier B.V. All rights reserved.