Medical Titanium Alloy Surface Modification And Biocompatibility

The application of biomedical metals of Ti6A14V alloy and TiNi shape memory alloy (SMA) exerts huge effect on promoting living quality of human beings. However, when being implanted into body, titanium alloy would be corroded inevitably resulting from the influence of body fluid, which will decrease the mechanical properties of metals, even result in implantation failure. And the metal ions of Al,V,Ni dissolved into body fluid have some side effect on the surrounding tissue, even leading to pathological changes or carcinomatous alteration. Hence, studies on corrosion resistance of biomedical metals have important practical sense in guaranteeing their safe application.The surface modification on Ti6A14V alloy and TiNi SMA was applied by physical vapour deposition (PVD) and electrochemical method, and tested corrosion resistance and biocompatibility of modified materials to research its possibility being biomaterials and feasibility of modification method.1. The new AlTiN coating was applied on the surface of Ti6A14V alloy by non-equilibrium magnetron sputtering high ionic pulse technology (H.I.P). The possibility of modified material to be a wear resistant biomaterial was researched by the test of wear and wore, electrochemical corrosion, Al,V ions release and blood compatibility, et al. Then the result is the surface modified material has better properties of wear and wore, the friction is only 0.007. And it also has better corrosion redisistance. Then it reduces the release of Al,V, and increases long-term reliabilitysafety.2. The TiNi SMA of equal atom ratio was anodic oxidized in ammonium salt by three electrode device. And the surface topography, corrosion resistance and the percentage composition of Ni in the anodic oxide film were checked. The result is the percentage composition of Ni in the anodic oxide film was reduced, and the atom ratio of Ti: Ni is 2.5. By the experiment of electrochemical corrosion and blood compatibility et al, the result of better corrosion resistance and blood compatibility is implemented. To be the better biomaterial in oral cavity, the good foundation is laid.3. The Ti-O film with contains a lot of OH" was prepared on the surface of TiNi SMA in Ti(SO₄)₂ solution by cathodic electrodeposition method, and the granular size of Ti-O film is from several decade to several hundred nanometer. The properties of Ti-O film in simulated physiological environment was checked by the method of electrochemical corrosion, biological activity and blood compatibility et al. And to find out optimum process, the effect of optimum process to Ti-O film was analysed. After all, in the condition of optimum process, the uniform Ti-O film with biological activity was realized. And it has advance properties of corrosion resistance and blood compatibility. The optimum process is the PH 1.2 of electrolyte puts in 0.2M NO₃^-, the current density is 5mA/cm², the time is 4min. The good foundation is laid to be a final treating process of untight oxidizing layer on the surface of TiNi SMA because of removing Ni in the process of oxidization.