OBRABOTKAMETALLOV MATERIAL SCIENCE Vol. 25 No. 2 2023 Fig. 5. Dependence of FWHM reflection of (111) CrN and (111) ZrN multilayer coating on temperature from 50 °C to 400 °C for the CrN phase. After reaching the temperature of 400 °C, the FWHM value increases and, accordingly, microstrains will also have an increasing dependence for the CrN phase. For the ZrN phase, the situation is reversed: the FWHM value decreases almost throughout the heating process, and accordingly, microstrains will only decrease. Table 2 presents the calculated values of interplanar distances (d, Å), the full width at half maximum (FWHM) values (degrees), as well as the calculated lattice parameter for the CrN/ ZrN multilayer coating obtained at a substrate holder rotation speed of 8 rpm using the known Equation 1 [20]. The CLTE calculations were performed using Equation 2 for each temperature point presented in Table 1. The X-ray diffraction pattern shows the reflections (111) of the CrN and ZrN phases of the multilayer coating in the selected temperature range. Ta b l e 2 Characteristics of reflections of all phases, presented in a sample with a multilayer CrN/ZrN coating, obtained at a substrate holder rotation speed of 8 rpm as a function of temperature Temperature, °C Reflection, phase d, Å FWHM, deg. a, nm 50 (111) ZrN 2.6596 1.1329 4.6065 (111) CrN 2.4595 1.5925 4.2599 100 (111) ZrN 2.6644 1.0414 4.6148 (111) CrN 2.4679 1.5137 4.2745 200 (111) ZrN 2.6671 1.0504 4.6195 (111) CrN 2.4633 1.6553 4.2665 400 (111) ZrN 2.6721 1.0941 4.6282 (111) CrN 2.4519 1.6526 4.2468 500 (111) ZrN 2.6732 1.0407 4.6301 (111) CrN 2.4595 1.6878 4.2599 550 (111) ZrN 2.6729 0.9904 4.6295 (111) CrN 2.4572 1.6518 4.25599524 600 (111) ZrN 2.6698 0.8949 4.62422925 (111) CrN 2.4739 1.652 4.28492049 The dependence of the crystal lattice parameter on the temperature is shown in Fig. 6, a. From the graph, it can be seen that the crystal lattice parameter of the coating materials (CrN and ZrN) increases, i.e., the material expands, and this occurs according to a linear law with some error. The dependence of the crystal lattice parameter change on the temperature of the coating materials (CrN and ZrN) is shown in Fig. 6, b. Equation 2 is applied as follows. Obviously, Fig. 6, b is a rearranged graph shown in Fig. 6, a, such that Δa = aT - a0, where aT is the lattice parameter at a higher temperature (in the case of Figures 6, a, b, the highest values on the linear segments: 50–550 °C), and a0 is the lattice parameter at the beginning of the linear segments (in the case of Figures 6, a, b, the lowest values on the linear segments: 50–550 °C). Thus,
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