The investigation of effect of Ta on adhesion and tribological properties of TiCN coatings

TiCN coatings are applied to the surfaces of tool steels to increase tool life due to their favorable 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. Therefore, in this study, to increase the life of AISI H13 tool steel; TiCN and Ta added TiCN coatings were deposited with closed area unbalanced magnetron sputtering (CFUBMS) system and the effects of Ta on the structural, mechanical and tribological properties of TiCN coatings were investigated. One Ta and one Ti target were used in the coating system. Ar, N2 and C2H2 gas ratios were maintained at 20 sccm, 5 sccm and 5 sccm, respectively. Before TiCN and Ta-TiCN coatings were grown; Ti: TiN interlayer was deposited on H13 tool steel to increase adhesion. In the process, the Ta target current has been changed to 0A, 3A and 6A. Structural properties of coatings were determined by SEM, XRD and XPS. Mechanical properties of coatings were obtained by nanoindentation and adhesion tests. Pin-on-disc tribotest device was used to determine 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 H13 steel.