Investigation on corrosion behavior of sputter-deposited nanocrystalline (MoxCr1−x)5Si3 films by double cathode glow plasma

Five kinds of nanocrystalline (MoxCr1−x)5Si3 (x = 1.00, 0.82,0.75,0.65,0.56) films with the average grain size of 40 nm have been prepared on the surface of AISI 316L stainless steel by a novel duplex surface treatment, consisting of chromizing pretreatment and a subsequent Mo-Cr-Si multi-element surface alloying by double cathode glow plasma. Corrosion behavior of nanocrystalline (MoxCr1−x)5Si3 films was determined by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) in 3.5 wt.% NaCl solution. The nature of the reaction products formed on the sputter-deposited films surface was analyzed by X-ray photoelectron spectroscopy (XPS). The results revealed that corrosion resistance of nanocrystalline (MoxCr1−x)5Si3 films apparently increased with the increasing additions of Cr to Mo5Si3, and constituents of passive films relied on the Cr content in the (MoxCr1−x)5Si3 films.