Wear-resistant PACVD coatings of the system Ti–B–N

The nitrides and borides of titanium are well known for their high hardness and excellent corrosion and wear resistance in many tribological systems. Titanium boronitrides are expected to combine the advantages of both binary layers and allow optimization for the demands of each specific application. This study focuses on the influence of the process gas composition as well as the plasma parameters on the properties of PACVD coatings within the system Ti–B–N. The stoichiometry can be controlled by the process-gas composition. The layer growth rate increases with increasing N 2 flow. For a fixed gas composition, it can be related to the supply of active layer-forming species. A high layer hardness is obtained at high ion energies and increases with decreasing N 2 flow. At a constant N 2 flow, layers with low boron contents reach a hardness of up to 4000 HK0.005, whereas Ti(B,N) with B concentrations above 20 at.% exhibits a lower hardness than that of TiN.