Determining the critical loads of V and Nb doped ternary TiN-based coatings deposited using CFUBMS on steels

Transition metal nitride coatings are very attractive materials due to their hardness and toughness. On the other hand, adhesion properties of these coatings are generally low because of their brittleness. To overcome this disadvantage, these coatings are produced with different deposition techniques. In this work, V and Nb doped ternary TiN-based coatings were deposited on M2 and H13 steel substrates with closed field unbalanced magnetron sputtering (CFUBMS) system. The microstructure and thickness properties were determined using Scanning Electron Microscope (SEM). The chemical composition of the coatings was examined by Energy Dispersive Spectroscopy (EDS) and X-Ray Diffraction (XRD). The mechanical properties of the coatings were carried out by nanohardness test. The critical load values (Lc) of the coatings were pointed out using a scratch tester. The thickness values of the coatings were 400 mu and 360 nm for TiNbN and TiVN, respectively. The highest thickness, nanohardness and Lc values were obtained from TiNbN coating. The maximum nanohardness and Lc values were measured as 35 +/- 1.8 GPa and 63 N from TiNbN coating on M2 steel, respectively. On the other hand, TiVN coating on both steels showed lower nanohardness and adhesion behavior. It was clearly seen that different substrates had an important effect on microstructure and mechanical properties of coatings.