The effect of argon ion implantation on the corrosion resistance of zirconium

The corrosion resistance of a Zr+1%Nb alloy bombarded with 25 keV argon ions has been investigated. Corrosion tests were performed in air at a temperature of +60/spl deg/C and a humidity of 98%. The duration of tests was 3500 hours. Improvement in alloy corrosion resistance is found to occur throughout the entire range of radiation doses under study (5/spl middot/10/sup 15/... 5/spl middot/10/sup 17/ ion/cm/sup 2/). However, the greatest reduction in the corrosion rate (by a factor of two) is observed for a dose of 4.10/sup 16/ ion/cm/sup 2/. The behavior of corrosion rate with variations in the radiation dose as well as the Rutherford backscattering data on argon content in irradiated specimens indicate that the observed decrease in the corrosion rate is due to the formation of barrier layers from inert gas atoms in the surface of irradiated materials.