Adhesion and wear of ZrN films sputtered on tungsten carbide substrates

The improvement of the adhesion of a coating film to the coated material and of its wear resistance is a fundamental aspect for protective hard coatings. As a consequence, the optimization of the deposition techniques is required to properly tune the film properties.Among the numerous materials for hard coatings, zirconium nitride (ZrN) is extensively studied for use in tribological applications, thanks to its high hardness, strong wear resistance, chemical stability and high corrosion resistance. In this work ZrN films were RF-sputtered on silicon and tungsten carbide substrates, with different assistance bias voltages applied to the substrate during the film deposition. Their adhesion and wear resistance properties were evaluated and correlated to the structural and compositional properties, showing the best responses (higher critical load and scratch hardness, and lower wear rate) when using a low negative bias voltage (− 5 V).

► ZrN films were sputtered at different assistance bias voltages.
► Hardness, adhesion and wear resistance properties were evaluated.
► Tribological properties were correlated to structural and compositional properties.
► Minimization of oxygen contamination helped to improve the tribological properties.
► The best adhesion and wear resistance were observed at low negative bias voltage.