| The chemical composition, structure, mechanical properties and blood compatibility of titanium oxide films deposited on Low Temperature Isotropic Carbon (LTI-carbon) were studied in this paper. Ion beam enhance deposition (IBED) method was used to synthesize titanium oxide films. During deposition, the incidence angles of titanium vapor stream and Xe~ ion beam to the substrate were both 45o~ The current density was fixed at 4O~iAIcm2. Ion beam energy, substrate temperature, and oxygen pressure were set as process variables, in order to synthesize a series of titanium oxide films with different structure or chemical composition. The effect of process parameters on the chemical composition and structure of titanium oxide films were studied. When oxygen pressure was lower than 1 .5x 1 O3Pa, the prepared films were all oxygen-lacked titanium oxide, whose 0/Ti ratio was lower than 2:1. As oxygen pressure increasing, the 0/Ti ratio increased. The prepared titanium oxide films were polycrystallite, weak in crystallization. The existed TiO and Ti203 phases have a random orientation, however, the existed Ti02 phase shows (100)- preferred orientation. Ion beam energy has some influence on the structure of the film. The higher the energy is, the more disordered the crystallite is. Neither the structure nor the chemical composition of the film is sensitive to the substrate temperature lower than 3000C. The element distribution of the film is very well along the depth profile. The film is compact with film density of 3.5g/cm2 or so. Mechanical properties of titanium oxide films were studied. The microhardness of ;~ vi ~ ABSTRACT titanium oxide films prepared at different experimental conditions is maintained between 900-4000 kg/mm2. The adhesion strength of titanium oxide films on LTI- carbon substrate is about 0.3 14?0.47 GPa. The deposition of Ti interlayer is benefit for improving the adhesion strength of the film. After 675500 times of opening and closing, a circle brasion trial appeared, whereas titanium oxide was still existed in this area. No peel of the film was obsevered. When the circulation increased to 1617000 times, a small part of the film that located at the inboard boundary of the wear trail peeled off, however, Ti still can be detected in the wear trail region. Blood compatibility of titanium oxide film was investigated through in vitro and in vivo experiments. The hemolysis rate experimental result shows that titanium oxide film almost has no globulicidal effect on the blood. Less platelets were adhered on titanium oxide films in comparison to LTI-carbon made in China, and most of them remain a normal shape. The pseudopodium and aggregation of platelet on LTI-carbon made in China is very seriously. Though the adhesion quantity of platelet on LTI-carbon made outside China is less than that made in China, the pseudopodium of these adhered platelets is very significant. The human serum albumin (HSA) and human fibrinogen (HFG) competition adhesion results show that the solution梒oncentration-increase of one protein will restrain the adsorption quantity of another protein. Titanium oxide film shows a rather weak adsorption property of both proteins in comparison to LTI-carbon, and it also shows a LISA-preferred adsorption property. Titanium oxide film also shows a better blood compatibility in the subsequent in vivo experiment. The reason for the improved blo...
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