## 3 Results  
After the deposition process led to the desired high-entropy alloy coatings, the samples were analyzed, and the results are presented here.  
The roughness test results are presented in Table 1. The obtained values indicate a relatively uniform roughness in both the longitudinally- and transversally-measured directions.  
Considering that the electrospray deposition is a manual process, the roughness of the coating was rather uniform, having a min. of 4.62 \(\upmu\)m and a max. of 6.05 \(\upmu\)m. The roughness did not influence the quality of the coating for this specific case.  
The electrospray-deposited coating was analyzed, and the results are presented in Figure 2. From the microstructural analyses results obtained on the sample's surface, a continuous deposition could be observed (Figure 2a), with homogenous plateaus (Figure 2b) where the surface topography presents the roughness degree. Due to the specific cooling conditions of the electrospray deposition process, some micro cracks and pores were observed on the surface of the deposited layers (Figure 2c), this phenomenon being often found in other fast solidification processes, such as laser deposition.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Sample Name**} & \multicolumn{2}{c}{**Longitudinal**} & \multicolumn{2}{c}{**Transversal**} \\ \cline{2-5}  & **Center (Ra (\(\upmu\)m))** & **Edge (Ra (\(\upmu\)m))** & **Center (Ra (\(\upmu\)m))** & **Edge (Ra (\(\upmu\)m))** \\ \hline \multirow{4}{*}{HEA\_M} & 5.96 & 4.09 & 5.28 & 4.96 \\  & 6.4 & 4.52 & 5.1 & 5.72 \\ \cline{1-1}  & 5.84 & 5.15 & 4.68 & 4.95 \\ \cline{1-1}  & 6.03 & 6.3 & 3.43 & 5.29 \\ \cline{1-1}  & 6.03 & 5.17 & 4.61 & 6.1 \\ \hline \multirow{2}{*}{
\begin{tabular}{c} Average \\ (Ra (\(\upmu\)m)) \\ \end{tabular} } & 6.052 & 5.046 & 4.62 & 5.404 \\ \hline \hline \end{tabular}
\end{table}
Table 1: Roughness measurement results for the CoCrFeNiMo\({}_{0.85}\) coating.  
Figure 1: Schematic figure of the electrospray deposition method performed for the experiments.  
The dendritic structures from Figure 2d are specific for the high-entropy alloys, which confirm the presence of the HEA coating. Due to the dendritic structures' reduced dimensions, the high-entropy alloy presents a high alloying degree and an improved homogeneity degree, where supplementary thermal treatments are not necessary.  
In the analyses results from Figure 3, a homogeneous deposition can be observed, where the particles are distributed uniformly on the entire surface with no separation on components or compounds being noticed. Even though the process took place in an argon atmosphere, the oxygen was present due to the deposition method. The oxygen quantity, for this case, did not affect the coating functionality.  
From the previous analyses performed on cross-sections taken from the coated areas, it was observed that the micro cracks and pores were present on the surface of the sample, with the structure not being affected [12].  
Figure 2: SEM and topography surface analyses results for the CoCrFeNiMo\({}_{0.85}\) HEA coating deposited by electrospray deposition technique; (**a**) electron microscopy result, (**b**) topography indicating homogenous plateaus, (**c**) topography—presentation of pores, (**d**) topography—dendritic structures are present.