Bioactivity of TC4 Titanium Alloy Surface after Electrochemical Polishing and Anodic Oxidation

The surface morphology and phase of electrochemical polished and anodic oxidized TC4 (Ti6Al4V) titanium alloys surface were studied, respectively, and then the treated alloys were immersed in simulated body fluid for 21 d to study its bioactivity. The results show that, comparing to the anodic oxidized surface, the electrochemical polished surface had more nano-scale cavities (fewer total cavitities), lower surface roughness and slightly higher bioactivity. The ratios of Ca to P of electrochemical polished polished surface and anodic oxidized surface were respectively 1.61 and 1.59, which were closed to that of hydroapatite (1.67).