Effect of Titanium ion implantation on the oxidation behaviour of zircalloy-4 at 500 °C

The beneficial effect of titanium ion implantation on the oxidation behaviour of zircalloy-4 at 500 °C was investigated. Titanium ions were implanted by a MEVVA source at an energy of 40 keV with dose 5×1016, 1×1017, and 2×1017 ion/cm2 at the maximum temperature 130 °C. Weight gain curves of the as-received and implanted zircalloy-4 were measured after oxidation in air at 500 °C for 100 min. It was found that improvement was achieved in the oxidation behaviour of titanium ion implanted samples compared with that of the as-received one. The valence of the oxides in the scale was analyzed by X-ray photoemission spectroscopy. Glancing angle X-ray diffraction was used to examine the phase transformation in the oxide films and is showed that the addition of titanium transformed the phase from monoclinic zirconia to hexagonal zirconia. Finally, the mechanism of improvements oxidation behaviour is discussed.