Ta Effect on Structural, Mechanical and Tribological Properties of TiCN Coatings

TiCN coatings are applied to tool steels surfaces to increase tool life because of attractive properties such as high hardness and toughness. The addition of different alloy elements to the structure of TiCN leads to significant improvements in their mechanical and tribological properties. In this study, to increase the life of AISI H13 tool steel, TiCN and Ta-doped TiCN coatings were deposited by Closed Field Unbalanced Magnetron Sputtering system and the effects of Ta on the structural, mechanical and tribological properties of TiCN coatings were investigated. The effect of the Ta target current has been studied by varying its value from 0 to 3 and to 6A. Structural properties were determined by SEM, XRD and XPS. Mechanical properties were obtained by nanoindentation and adhesion tests. A pin-on-disk tribotest device was used to determine the tribological properties (friction coefficient and wear rate). With the addition of Ta to TiCN, an increase in the thickness of the coatings and a decrease in grain size were observed. The amount of C-C (sp3) increased in TiCN coatings with increasing Ta target current. Increased sp3 amount increased the hardness of the coatings. The results show that the increasing amount of Ta improves the mechanical and tribological properties of TiCN coatings. In addition, TiCN and Ta-TiCN coatings significantly improved the mechanical and tribological properties of substrate. © 2022, ASM International.