OBRABOTKAMETALLOV MATERIAL SCIENCE Vol. 24 No. 3 2022 preferential orientation relationship between ZrN and CrN during deposition at low rotation rates while it is violated at higher rotation rates with the common zone axis rotation and partial misorientation of the ZrN. Azimuthal ZrN/CrN layer misorientation is higher in samples ZrN/CrN-0.5 and ZrN/CrN-3.5, deposited at low rotation rates. For comparison, the azimuthal misorientation in these samples was about 18° as compared to 6° in the ZrN/CrN-8 (Fig. 3, b–d). Therefore, sample rotation during deposition has some effect on the coating microstructure, in particular, the orientation relationship between the layers. Such an effect may be the reason behind the residual stresses formed in the coatings during cooling. Residual stress level is one of the most important characteristics that determine mechanical and functional characteristics of the multilayer coatings. Therefore, the research can not be limited only by studying the microstructures only. Residual stress levels were studied using the well-known sin2Ψ-method but with utilizing the synchrotron X-ray radiation. Quantitative stress level can be estimated using expression 1 as follows [19]: 0 2 (2 ) ctg [MPa], 2(1 ) 180 (sin ) x x ÌÏ E (1) Fig. 2. Bright fi eld image of multilayer coating formed at ZrN/CrN-0.5 (a), ZrN/CrN-3.5 (b), ZrN/ CrN-8 (c) and linear approximation of the table and substrate holder rotation speeds as a function of the thickness of nanometer coating layers (d) a b c d
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