Superhard TiAlCN coatings prepared by radio frequency magnetron sputtering

• Superhard TiAlCN coatings were prepared by magnetron sputtering.
• The phase compositions of the TiAlCN are sensitive to the N2 flow rate.
• Nanocomposite structure contributes to the high hardness of 41 GPa.

In this work, we report on the formation of super-hard TiAlCN coatings developed through radio frequency magnetron sputtering. The phases and the mechanical properties of the TiAlCN coatings can be tailored by adjusting the carbon and nitrogen contents. Moreover, the TiAlCN coating with an optimized carbon and nitrogen content exhibits a hardness exceeding 40 GPa. The refined nanocomposite structure was composed of face-centered cubic (Ti,Al)(C,N), hexagonal close-packed AlN crystals and amorphous carbon that may contribute to the superior hardness.