Studies on the corrosion behavior of cerium-implanted zircaloy-4 with GAXRD

In order to study the influence of cerium ion implantation on the aqueous corrosion behavior of zircaloy-4, specimens were implanted by cerium ions with a fluence range from 1×10¹⁶ to 1×10¹⁷ ions/cm² at maximum 150°C, using MEVVA source at an extracted voltage of 40 kV. The valence and elements penetration distribution of the surface layer were analyzed by X-ray photoelectron spectroscopy (XPS) and auger electron spectroscopy (AES) respectively. Glancing angle X-ray diffraction (GAXRD) was employed to examine the phase transformation due to the cerium ion implantation in the oxide films. Three-sweep potentiodynamic polarization measurement was employed to value the aqueous corrosion resistance of zircaloy-4 in a 1 N H₂SO₄ solution. It was found that a significant improvement in the aqueous corrosion behavior of zircaloy-4 implanted with cerium ions compared with that of the as-received zircaloy-4. The improvement effect will declined with raising the implantation fluence. The bigger is the fluence, the less is the improvement. Finally, the mechanism of the corrosion behavior of the cerium-implanted zircaloy-4 is discussed.