The effect of TiN and CrN interlayers on the tribological behavior of DLC coatings

The constant demand for new materials is coupled with a growing interest in thin coatings that will improve the performance-related parameters of an element without increasing its volume or changing the material structure. The aim of this study was to determine the influence of TiN and CrN interlayers on the tribological properties of a-C:H:W-type diamond-like carbon (DLC) coatings deposited on HS6-5-2 steel using the physical vapor deposition (PVD) method. The effect of the interlayers was established by analyzing the structure, surface topography, chemical composition and tribological properties of the DLC coatings. The coatings were tested under dry friction conditions at the nano-, micro- and macroscales. An atomic force microscope (AFM) was employed to analyze the coating surface topography and perform tribological testing at the nanoscale. The microscale tests were conducted using a microtribometer, while the macroscale tests were carried out with a ball-on-disc contact tester. The results confirmed that the two interlayers improved the tribological properties of components with DLC coatings.