## 3 Results and Discussion
\begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Sample Conditions**} & **Surface Roughness** **Ra** & **Surface Roughness** & **Surface Hardness** \\  & **(\(\mu\)m)** & **Rq (\(\mu\)m)** & **(HR15N)** \\ \hline As polished Ti64 & 0.09 \(\pm\) 0.01 & 0.16 \(\pm\) 0.01 & 79.8 \(\pm\) 0.4 \\ \hline
0.5 M HF electrochemical corrosion & 0.23 \(\pm\) 0.02 & 0.30 \(\pm\) 0.02 & 78.5 \(\pm\) 0.5 \\ \hline
0.5 M H\({}_{2}\)SO\({}_{4}\) electrochemical corrosion & 0.32 \(\pm\)0.03 & 0.39 \(\pm\)0.03 & 78.5 \(\pm\) 0.9 \\ \hline
0.5 M NaF electrochemical corrosion & 2.25 \(\pm\) 0.41 & 2.92 \(\pm\) 0.02 & 84.3 \(\pm\) 0.4 \\ \hline
0.5 M HNO\({}_{3}\) electrochemical corrosion & 1.20 \(\pm\) 0.13 & 1.67 \(\pm\) 0.08 & 83.1 \(\pm\) 0.2 \\ \hline
0.5 M NaF/0.5 M H\({}_{2}\)SO\({}_{4}\) electrochemical corrosion & 0.23 \(\pm\) 0.02 & 0.30 \(\pm\) 0.02 & 78.5 \(\pm\) 0.5 \\ \hline
0.5 M NaF/0.5 M HNO\({}_{3}\) electrochemical corrosion & 0.32 \(\pm\)0.03 & 0.39 \(\pm\)0.03 & 78.5 \(\pm\) 0.9 \\ \hline
0.5 M HCl/0.5 M HNO\({}_{3}\) electrochemical corrosion & 2.25 \(\pm\) 0.41 & 2.92 \(\pm\) 0.02 & 84.3 \(\pm\) 0.4 \\ \hline
0.5 M HF/0.5 M HNO\({}_{3}\) electrochemical corrosion & 1.20 \(\pm\) 0.13 & 1.67 \(\pm\) 0.08 & 83.1 \(\pm\) 0.2 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Surface characteristics of Ti-6 Al-4V alloy after various electrochemical corrosion treatments. The table presents surface roughness parameters (Ra and Rq) and surface hardness (HR15N) for different single and mixed electrolyte treatments. Treatments include HF, H\({}_{2}\)SO\({}_{4}\), NaF, HNO\({}_{3}\), and their combinations. Values are presented as mean \(\pm\) standard deviation. Particularly noteworthy is that the shot peening treatment parameters of 1 kg/cm\({}^{2}\) and 10 s (Figure 11c) seem to provide the best surface characteristics, promoting uniform cell distribution and diverse morphologies. This may represent an optimal balance point of surface roughness and chemical composition, providing sufficient mechanical anchoring points while maintaining appropriate surface energy and bioactivity. This study selected two electrochemical corrosion treatment methods, 0.5 M HF/0.5 M HNO\({}_{3}\) and 0.5 M HNO\({}_{3}\), for cell attachment experiments. The reason for this choice lies in their representation of two different surface modification strategies. The 0.5 M HF/0.5 M HNO\({}_{3}\) combination was chosen because previous surface morphology analysis showed that this treatment method could produce a structure closest to the ideal surface (surface covered with bowl-shaped hemispherical pits) described in the literature [8]. The 0.5 M HNO\({}_{3}\) treatment served as a control group to evaluate the effect of a single strong oxidizing acid on surface characteristics and cellular behavior. This comparative design allows us to directly assess the role of HF in the surface modification process. Figure 12 demonstrates cell attachment on the Ti-6 Al-4V alloy after these two electrochemical corrosion treatments, observed through OM and SEM. The results reveal the significant impact of surface treatment methods on cellular behavior, providing important evidence for optimizing the surface design of biomedical implants. The surface treated with 0.5 M HF/0.5 M HNO\({}_{3}\) electrochemical corrosion (Figure 12a,b) exhibits excellent cell attachment effects. Cells show uniform distribution on the surface with diverse morphologies, including round initial attachment cells and spread irregular-shaped cells. This diversity and uniformity indicate that the surface treatment successfully created a microenvironment conducive to cell attachment, spreading, and growth. SEM observations further confirm the close interaction between cells and the surface, showing extended cell pseudopodia and intercellular connection structures. In contrast, the surface treated with 0.5 M HNO\({}_{3}\) electrochemical corrosion (Figure 12c,d) presents a markedly different cellular behavior pattern.