Titanium nitride (TiN) coatings were deposited on hot-work steel (DIN 1.2367) by plasma-assisted chemical vapor deposition (PACVD) and the influence of different N-2/H-2 gas flow ratio on the layer properties were investigated. Scanning electron microscopy studies shows that the growth rate increases with increasing N-2/H-2 gas flow ratio. It was learned the TiN layers are nearly stoichiometric, except for low N-2 gas flows. Grazing incidence X-ray diffraction (GIXRD), scanning electron microscopy (SEM) and pin-on-disk test were used to evaluate the microstructure as well as tribological properties such as friction, wear, and hardness. It was also revealed that by increasing the flow ratio, the grain size of the TiN coatings decreased. A hardness of 1710 HV0.05 was obtained when the layer was fabricated at the higher flow ratios.
Keywords: PACVD; TiN coating; Tribology; Gas mixture