OBRABOTKAMETALLOV MATERIAL SCIENCE Vol. 24 No. 1 2022 Fig. 10. Indentation depth variation profi les during scratching coatings: CrN (1), ZrN (2), ZrCrN-1 (3), ZrCrN-2 (4), ZrCrN-3 (5), ZrCrN-4 (6). CrN coating, judging from the greatest scratch depth along the cleavage (Table 2), locally detached from the substrate during fracture, which can be explained by its high brittleness against diamond indentation. ZrN coating, judging from the same value (Table 2), was not damaged over the entire thickness, as it has higher mechanical properties compared to CrN. The review of literature in [19] provides similar information on the fracture of ZrN, CrN, and CrN/ZrN coatings, showing that multilayer CrN/ZrN coatings have better properties compared to ZrN and CrN coatings. Conclusions Experimental studies were performed to investigate the structure, phase composition, and mechanical properties of CrN, ZrN, and ZrCrN coatings. It was found that the structure, morphology, surface roughness, and mechanical properties of multilayer ZrCrN coatings are greatly affected by changes in the deposition conditions. X-ray diffraction analysis data indicate the absence of pronounced texture in ZrCrN-2…ZrCrN-4 coatings, and the broadening of the refl ections is testimony to the nanostructured state of the layers. An increase in the rotation speed of the substrate holder relative to the Cr and Zr cathodes leads to a more pronounced surface microroughness. Increasing the holder rotation speed from 0.5 to 8 rpm during coating deposition causes an ~38 % monotonic increase in surface roughness in terms of the Sa parameter. The change in terms of the Sz parameter is less signifi cant and does not exceed 12 %. The investigation results showed that by varying the deposition conditions it is possible to obtain a ZrCrN coating (ZrCrN-4 sample) with a high nanohardness of 45 GPa on VK8 alloy. The nanohardness of multilayer ZrCrN coatings is by a factor of 1.14–2.1 higher than that of CrN and ZrN coatings. The H/E ratio values indicate that ZrCrN-2…ZrCrN-4 coatings are more resistant to mechanical loads. Scratch tests revealed that fracture of CrN and ZrN coatings occurs by the cohesive mechanism. The surface of multilayer ZrCrN coatings exhibits uniform scratches without signs of coating fracture. The results obtained confi rmed good adhesion of all the studied coatings to the substrate. Based on the study results, ZrCrN-2…ZrCrN-4 coatings can be recommended for use as hard and wearresistant coatings. The results obtained will be used for more detailed XRD studies of multilayer coatings using synchrotron radiation from the VEPP-3 storage ring of the Siberian Synchrotron Radiation Center at the Budker Institute of Nuclear Physics SB RAS.
RkJQdWJsaXNoZXIy MTk0ODM1