A Study On Technique And Property Of Anodic Oxidation On Biomedical Pure Titanium

DC pulses constant voltage anodic oxidation coloring technology was used to deal with TA2 pure titanium in this paper. The effects of different processing parameters, pre-treatment and sealing treatment on color quality of anodic oxidation films were researched. The film forming mechanism of pure titanium anodic oxidation film and the applications of pure titanium implants using anodic oxidation treatment were showed. The color, morphology, elements, phase, valence state of films were investigated by digital camera (DC), scanning electron microscopy (SEM), X-ray spectrum (EDAX), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS). The adhesion of oxide films were tested by delimit lattice and bending test, the corrosion resistance of oxide films were tested by electrochemical workstation.The results indicated that the electrolyte voltage was the main factor affecting the coloring of films, and the colors change with voltage shifting. The uniformity colored films on TA2 pure titanium were obtained by anodic oxidation in alkaline, acidic and neutral electrolyte, but films color which were generated in the same voltage were somewhat different in different electrolyte. The uniformity and integrality of film color was obtained in moderate concentration of electrolyte, the film color was heterogeneous when the H₃PO₄ solution concentration was too low, corroded defect was produced in film when the H₃PO₄ solution concentration was too high. The uniformity was worse when the H₃PO₄ solution temperature become higher, the better film was obtained at room temperature. The best quality film was obtained when the oxidation time was controlled at film growth-dissolve balance stage. The effects of pure titanium coloring effect was surface pre-treatment, the ability to fight pollution of film was improved by hole sealing post-treatment.The uniformity of film was recorded in digital camera, delta-E was less. Scanning electron microscopy indicated there is a porous and flat oxidation film on the surface of TA2 pure titanium. The analysis results of X-ray spectrum showed that the film consisted mainly of Ti and O element. The film was too thin, phase of anodic oxidation film was uncertain according to X-ray diffraction analysis. The analysis results of X-ray photoelectron spectroscopy showed that the film consisted mainly of four valence titanium and bivalent oxygen constitute. The film valence basically unchanged along with the increase of the depth of sputtering. Delimit lattice and bending tests indicated that the film and substrate combined firm, the adhesion of film was good. Electrochemical analysis indicated that the corrosion resistance of the film was improved with the increased of voltage. The corrosion resistance of titanium implant materials in body physiological environment was improved through the anodic oxidation coloring treatment.