Abstract:
To improve the implantation stability and biological activity of the hydroxyapatite(HA) coating on the surface of medical TC4 titanium alloy, CaP bioceramic coating with different silicon contents were prepared by laser cladding method. Scanning electron microscopy(SEM) and X-ray diffractometry(XRD) were used to characterize the morphology and phase composition of the cladding layer. The results showed that the Ca2SiO4 phase was formed and the microstructure of the middle zone of the cladding layer was refined after adding SiO2(1wt.%, 3wt.%). The effects of SiO2 content on the corrosion resistance and bioactivity of the coating were investigated by electrochemical corrosion and in vitro SBF immersion experiments. Electrochemical corrosion results showed that the corrosion current density of the coating surface decreased with the increase of SiO2 content; The results of SBF soaking in vitro showed that the addition of SiO2 could accelerate the formation of bone-like apatite on the surface of the coating. When the content SiO2 was 1 wt.%, the surface of the coating-like bone apatite was uniformly distributed. Therefore, low-content SiO2 can improve the corrosion resistance and bioactivity of bioceramic coatings.