Corrosion behavior in 1 N H2SO4 of zirconium ion implanted with nickel

In order to study the effect of nickel ion implantation on the aqueous corrosion behavior, specimens of zirconium were implanted by nickel ions with doses ranging from 1×1016 to 5×1017 ions/cm2, using a MEVVA source at an extraction voltage of 40 kV. The valence states and depth distribution of elements in the surface layer of the samples were analyzed by X-ray photoelectron spectroscopy (XPS) and auger electron spectroscopy (AES), respectively. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to examine the micro-morphology and microstructure of the nickel-implanted samples. Potentiodynamic polarization measurements were employed to evaluate the aqueous corrosion resistance of the zirconium in a 1 N H2SO4 solution. In the first sweep polarization, the passive current densities at dose of 1×1016 and 5×1016 ions/cm2 are lower than that of as received zirconium. While in the third sweep polarization, the passive current densities of all the implanted samples are higher than that of as received zirconium. Finally, the mechanism of the corrosion behavior of the nickel-implanted zirconium is discussed.