| Titanium alloys, such as Ti6A14V, are widely used in biomedical fields due to their high specific strength, good biocompatibility and excellent corrosion resistance. However, they have poor wear resistance, and there is a risk of bacterial infections after implantation in human body. Therefore, proceeding from the surface of the materials to seek more desirable surface modification process is also a very promising approach. In this study, Ti/Cu/N films with different Cu content have been deposited on Ti6A14V substrates, using composed Ti-Cu targets by reactive dc magnetron sputtering method. The organizational structure and basic mechanical properties of the films were measured and characterized. And the paper focused on the Cu content influence on the coating/substrate adhesion, friction and wear properties and antibacterial activities of these films, and the antibacterial mechanism was also discussed. The conclusions are as follows:(1) All of the three Ti-Cu alloy targets with different Cu contents obtained uniform and dense Ti/Cu/N composite films of which the surface modification multilayers are comprised of Ti/Cu film and Ti/Cu/N film. Besides, TiN is formed in the Ti/Cu/N layer. And with the area ratio of Cu bar in the target elevates, the content of Cu in the membrane increases and the content of main element Ti and N also change.(2) As the content of Cu in the film vary, the surface morphology of the film change. On the macro level, three samples present different color; on the micro level, the roughness of three samples increase with the elevation of Cu content in the composite film.(3) The results of hardness test show that the composite hardness of the coated samples has enhanced compared with uncoated ones. But with the elevation of Cu content, the hardness decreases.(4) Study the adhesion performance of the systems, the critical loads of the samples are about19.5N,18.2N and17.1N, respectively, the differences are small. There exists great difference in the scratch failure maps of the samples, but they reflect the performance of plastic deformation properties and there have appeared the cohesive failure form of the films.(5) Analyze the friction and wear performance of the coated samples in the atmosphere and Hank’s solution environmental media, find that the friction coefficient of the sputtering deposition samples is lower than the matrix. The results explain that these films have obvious anti-friction effect in the two friction conditions. Sample C2in the two kinds of environmental media show good wear-resisting performance. But in Hank’s solution environment media the wear properties of samples and matrix are better than that in atmospheric condition.(6) The antibacterial activities of the samples are studied, the comparison with the Ti6A14V substrate illustrates that the films show good comparison antibacterial effect. And Cu plays a key role in the process of antibacterial, the higher the Cu content, the better the antibacterial effect. According to the existence state of Cu metal after antibacterial test and antibacterial mechanism action of antimicrobial metal particles, the more the antimicrobial metal Cu2+particles which releasing from the surface slowly, the better the bactericidal effect. |
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