Size-dependent radiation tolerance and corrosion resistance in ion irradiated CrN/AlTiN nanofilms

This paper demonstrates a substantial enhancement in radiation tolerance and corrosion resistance for the CrN/AlTiN multilayered nanofilms with the decreasing of period-thickness. After irradiation by 190 keV Ar+ ions to the dose of 81 dpa, the amorphization region in the CrN/AlTiN 3 nm multilayered nanofilm is much smaller than that in the CrN/AlTiN 7 nm multilayered nanofilm and the CrN film based on glancing-incidence X-ray diffraction measurements. Potentiodynamic polarization and impedance measurements show that the CrN/AlTiN multilayered nanofilms have good corrosion resistance to irradiation. With increasing the irradiation fluence, the irradiated samples are more susceptible to corrosive electrolyte. However, the CrN/AlTiN multilayered nanofilm with smaller period-thickness shows significant enhancement of the corrosion resistance under both irradiation and un-irradiation conditions. Under the same irradiation fluence of 5 × 1016 ions/cm2, the corrosion current density increased 9.47 times for the CrN film, while it only increased 2.08 times for the CrN/AlTiN 3 nm multilayered nanofilm. The interfaces of multilayered nanofilms act as effective sinks for irradiation-induced defects and are responsible for the enhanced radiation tolerance and corrosion resistance properties.