Influence of lanthanum ion implantation on the aqueous corrosion behavior of zirconium

In order to investigate the effect of lanthanum ion implantation on the aqueous corrosion behavior of zirconium, specimens were implanted with lanthanum ions at a dose ranging from 1×1016 to 1×1017 ions/cm2 at maximum 130 °C, using a metal vapor vacuum arc (MEVVA) source at an extracted voltage of 40 kV. The valence of the surface layer was analyzed by X-ray photoemission spectroscopy (XPS). Three-sweep potentiodynamic polarization measurement was employed to determine the aqueous corrosion resistance of zirconium in a 1 N H2SO4 solution. It was found that a significant improvement was achieved in the aqueous corrosion behavior of zirconium implanted with lanthanum ions compared with that of the as-received zirconium. Finally, the mechanism of improvement in the corrosion resistance of the lanthanum-implanted zirconium is discussed.