## 4 Conclusions  
The amorphous coatings Ta-Zr-Si-B-C and Ta-Zr-Si-B-N containing 12 at.% C and 20 at.% N were deposited by magnetron sputtering using a TaSi\({}_{\text{2}}\)-Ta\({}_{\text{3}}\)B\({}_{\text{4}}\)-(Ta,Zr)B\({}_{\text{2}}\) ceramic target in Ar + C\({}_{\text{2}}\)H\({}_{\text{4}}\) and Ar + N\({}_{\text{2}}\) reaction media, respectively. According to XPS data, Ta is predominantly bonded to Si, and Zr is predominantly bonded to B. In addition, Ta-C and Si-C bonds were detected for the carbon-containing coating, and Ta-N, Zr-N and Si-N bonds were detected for the nitrogen-containing coating. The Ta-Zr-Si-B-C coating was characterized by higher values of hardness of 25 GPa and an elastic modulus of 259 GPa compared to 25 GPa and 229 GPa for the Ta-Zr-Si-B-N coating. The high mechanical properties of the carbon-containing coating are ensured by the presence of Ta-C and Si-C carbide bonds. In situ TEM heating led to the crystallization of the amorphous Ta-Zr-Si-B-C coating at a temperature of 600 \({}^{\circ}\)C with the precipitation of the h-TaSi\({}_{\text{2}}\) and c-TaC phases. The Ta-Zr-Si-B-N coating crystallized during holding at 1000 \({}^{\circ}\)C with the precipitation of the h-Ta\({}_{\text{5}}\)Si\({}_{\text{3}}\) and c-TaN phases. The XRD and XPS data of vacuum-annealed coatings correlate well with the TEM data. Crystallization of the Ta-Zr-Si-B-C coating was observed at a temperature of 600 \({}^{\circ}\)C, with the formation of a nanocomposite structure with h-TaSi\({}_{\text{2}}\) and c-TaC crystallites -10-20 nm in size and an amorphous interlayer based on a-Si(Zr,B)C, whereas the Ta-Zr-Si-B-N coating crystallized at 1000 \({}^{\circ}\)C, with the formation of h-TaSi\({}_{\text{3}}\) and c-TaN crystallites \(\sim\)6-10 nm in size, surrounded by an a-Si(Zr,B)N amorphous matrix. An increase in temperature led to a decrease in the hardness of the carbon-containing coating from 25 to 16 GPa at 1000 \({}^{\circ}\)C as a result of stress relaxation. For the Ta-Zr-Si-B-N sample at a temperature of 1000 \({}^{\circ}\)C, an increase in hardness from 23 to 27 GPa was observed, which is associated with the crystallization of the coating and the formation of a nanocomposite structure with an optimal crystallite size of about 6-10 nm. The combination of high mechanical and tribological characteristics with high oxidation resistance and good thermal stability makes Ta-Zr-Si-B-C coatings promising as protective coatings for parts of heavily loaded friction units. High-oxidation-resistance coatings are ensured due to the formation of SiO\({}_{\text{2}}\)+ B\({}_{\text{2}}\)O\({}_{\text{3}}\) and Ta\({}_{\text{2}}\)O\({}_{\text{5}}\) oxides. High wear resistance is achieved due to free carbon, which acts as a solid lubricant, and due to the formation of TaSiO\({}_{\text{x}}\) particles, which reduce friction. Ta-Zr-Si-B-N coatings, due to their high oxidation resistance, their high thermal stability and the absence of phase transformations, can be used as coatings for high-temperature microelectronic resistors. The hardening effect of coatings can also be used to improve the performance of high-performance dry machining tools. A logical continuation of this work is the study of higher concentrations of nitrogen and carbon regarding the thermal stability of coatings, as well as the study of the thermodynamics of phase transitions and the study of crystallization kinetics. **Supplementary Materials:** The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/app13810440/s1](https://www.mdpi.com/article/10.3390/app13810440/s1)]([https://www.mdpi.com/article/10.3390/app13810440/s1](https://www.mdpi.com/article/10.3390/app13810440/s1)), Video S1: Movement of the crystallization front in the Ta-Zr-Si-B-N coating at 1000 \({}^{\circ}\)C.  
**Author Contributions:** Conceptualization, A.D.S. and P.V.K.-K.; formal analysis, A.D.S. ; investigation, A.D.S., P.A.L. and P.V.K.-K.; resources, E.A.L. ; writing--original draft preparation, A.D.S.