Improved corrosion behavior of nanocrystalline Cu-20Zr films in HCl solution

Nanocrystalline Cu-20Zr (wt.%) films were obtained from the cast master alloy by magnetron sputtering. Potentiodynamic polarization, electrochemical impedance spectroscopy, and scanning electron microscopy were employed to characterize the Corrosion behavior of the sputtered nanocrystalline Cu-20Zr films and the corresponding cast Cu-20Zr alloy in HCl aqueous solutions with various concentrations (0.1, 0.5 and 1.0 mol L-1). Results showed that the corrosion resistance of the sputtered nanocrystalline Cu-20Zr films is superior to that of the cast Cu-20Zr alloy. The improvement of the corrosion resistance through nanocrystallization is explained by (i) the formation of a continuous Cu-rich layer at the corrosion potential, and (ii) the formation of a copper-chloride complex layer in the potential range for simultaneous dissolution of Cu and Zr. (c) 2006 Elsevier B.V. All rights reserved.