## 5 Conclusions  
In the article, selected properties of the Ti layer deposited on the inner surface of the steel tube, which was created by the EB PVD method, were monitored. Experimental measurements were carried out at different heights of the measured place above the target (from 305 mm to 425 mm, difference of 30 mm) and at different radii of the steel tube (from 100 mm to 140 mm, difference of 10 mm). Several conclusions emerge from the analysis of the results of the experimental measurements:  
* The Ti coating has a columnar microstructure,
* with the given settings of the input variables (height of the measured place above the target, radius of the tube), the grain growth angle takes values from 40\({}^{\circ}\) to 61\({}^{\circ}\),
* there is a significant influence of the height of the measured place above the target and the radius of the tube on the grain growth angle,
* the angle of growth of the grains increases with the increasing radius of the tube, on the contrary, the increase of the height of the measured place above the target causes a decrease in the angle of growth of the grains
* there is a significant influence of the height of the measured location above the target and the tube radius on adhesion,
* there is a significant effect of the height of the measured location above the target on the thickness of the deposited layer,
* the influence of the height of the measured place above the target and the radius of the tube on the roughness of the deposited layer was not confirmed. Experiments have shown that it is possible to use the EB PVD method with the above-mentioned main technological parameters of the deposition process of the evaluated Ti layer to create thin Ti layers on the inner cylindrical surfaces. The created regression model is obtained from measurements that are the result of experimental research, and its significance is also confirmed by testing statistical hypotheses. A graphical representation of the values obtained by experimental research and the theoretical values obtained from the model is available. In the planned repeated experimental measurement, the authors' effort is to confirm the obtained relationships. \begin{table}
\begin{tabular}{l c c c c c} \hline \hline \multicolumn{1}{c}{\multirow{2}{*}{**Parameter**}} & \multirow{2}{*}{**Estimate**} & \multicolumn{2}{c}{**The Lower Bound of**} & \multicolumn{1}{c}{**The Upper Bound of**} & \multirow{2}{*}{**\(p\)-Value**} & \multicolumn{2}{c}{**Statistical Significance of**} \\  & & **the 95\% Estimate** & & & **the Parameter** \\ \hline Intercept & 0.439 & 0.310 & 0.567 & \(4\times 10^{-7}\) & \\ X\({}_{1}\) & \(-\)0.00004 & \(-\)0.00029 & 0.00021 & 0.743 & Non-significant \\ X\({}_{2}\) & 0.00022 & \(-\)0.00053 & 0.00097 & 0.549 & Non-significant \\ \hline \hline \end{tabular}
\end{table} 
Table 10: Estimates of regression model parameters (Model V, \(\alpha\) = 0.05). M.A. : Conceptualization, Methodology, Software, Validation, Formal analysis, Data curation, Writing--original draft preparation, Writing--review and editing, Visualization. D.K. : Conceptualization, Methodology, Investigation, Resources and data curation, Writing--review and editing, Visualization. A.G.: Conceptualization, Resources, Writing--original draft preparation, Writing--review and editing, Visualization, Supervision, Project administration. M.J.: Validation, Formal analysis, Investigation, Data curation, Visualization. All authors have read and agreed to the published version of the manuscript. This research received no external funding. Not applicable. The datasets presented in this article are not readily available because the data are part of an ongoing study. The data presented in this study are available on request from the corresponding author. This work was financially supported by the Slovak Grant Agency under the grants VEGA 1/0191/24 and KEGA 013 TUKE-4/2023. The authors declare no conflicts of interest.