The Influence of the Elemental Composition on the Mechanical and Tribological Properties of TiAlN Coatings

This work investigates the dependence of the mechanical and tribological properties of TiAlN coatings on the Al/Ti ratio. The coatings were obtained by dual high power impulse magnetron sputtering of metallic Ti and Al targets. It is shown that the hardness of TiAlN coatings with an Al/Ti ratio ranging from 0.04 to 0.77 is 30 ± 1 GPa. As the Al content increases, the modulus of elasticity decreases from 400 to 330 GPa, while the resistance to plastic deformation H³/E² and the plasticity index H/E increase (from 0.19 to 0.28 GPa and from 0.08 to 0.09, respectively). The best wear resistance of the coating (wear rate of 8.4 × 10^‒8 mm³ N^‒1 m^‒1) is observed for the coating with an Al/Ti ratio equal to 0.58.