Structural and mechanical properties of cubic chromium nitride films modulated by nitrogen flow rate and assisting ions

Metal nitrides are promising and widely used coating materials for their excellent hardness, wear resistance, corrosion resistance, and good chemical stability. In this work, chromium nitride (CrNx[jls-end-space/]) films were prepared by dual ion beam deposition. The structure and mechanical properties including hardness, elastic modulus, and film–substrate adhesion strength of the films were characterized. The influence of N₂ flow rate Qn and assisting ion energy Ea and current Ia on the microstructure and mechanical properties of the films were systematically investigated. The results revealed that as one of these parameters increases, all the hardness, elastic modulus, and critical load initially increase and then decrease. At optimal parameters, the CrNx film achieved a hardness of 23.9 GPa and a critical load of 212 mN, which demonstrates an optimal combination of high hardness and strong film–substrate adhesion. The findings confirm that assisting ion beam technology enables the fabrication of high-performance CrNx films.