Effect of Helium ion irradiation on the structure, the phase stability, and the microhardness of TiN, TiAlN, and TiAlYN nanostructured coatings

The radiation resistance of nanostructured TiN, TiAlN, and TiAlYN coatings is studied after 500-keV He$^+$ ion irradiation in the fluence range 5 $\times$ 10$^{16}$–3 $\times$ 10$^{17}$ ions/cm$^2$. The radiation-induced changes in the phase composition, the structure, the lattice parameters, the morphology, and the mechanical properties of coatings are investigated. Blistering is found to be absent, and the radiation fluence is shown to affect the strength properties of the thin coatings nonlinearly. A significant decrease in the grain sizes is detected upon ion irradiation, which causes an increase in the microhardness and the radiation resistance of the coatings. The TiN, TiAlN, and TiAlYN coatings are found to be radiation-resistant coatings, which do not undergo serious degradation during high-fluence ion irradiation.