EVALUATION OF THE TRIBOLOGICAL PROPERTIES OF CHROMIUM NITRIDE AND DIAMOND-LIKE CARBON COATINGS DEPOSITED ON X38CrMo16 STEEL

<ns3:p>This study investigates the tribological properties of chromium nitride (CrN+OX) and diamond-like carbon (DLC) coatings. Polished samples (Ra = 0.02÷0.03 m) were coated with commercial DLC and CrN+OX coatings, as well as a DLC coating deposited in accordance with a proprietary procedure. The coatings were applied using the plasma-assisted chemical vapor deposition (PACVD) method. Surface topography was analyzed under a Leica DCM8 confocal microscope to compare surface parameters before and after coating deposition. Tribological tests were performed using a TRB3 tribometer in a ballon-disc configuration under 10 N load in reciprocating motion under dry friction conditions. Additionally, tribological tests for the proprietary DLC coating were conducted at increased loads of 15 N and 20 N. The measurements of the coefficient of friction and linear wear were recorded. To compare the wear tracks after tribological tests, further observations were performed using a confocal microscope. Surface topography analysis indicated that DLC coatings had little effect on surface roughness parameters, in contrast to the CrN coating. The tribological test results demonstrated that all applied coatings significantly reduced both the coefficient of friction and wear. The lowest coefficient of friction was recorded for the sample with the DLC coating deposited using the proprietary procedure developed at the Advanced Nanotechnology and Nanomaterials Laboratory at the Kielce University of Technology. Meanwhile, the lowest linear wear was observed for the sample with the commercial DLC coating. Microscopic profile analysis revealed that the smallest wear track depth was obtained for the sample coated with DLC using the proprietary deposition process.</ns3:p>