Microstructure, Mechanical and Antibacterial Properties of TiNb-Based Alloy Implanted by Silver Ions

In this study, in order to obtain an antibacterial property for the TiNb-based alloy, the metal vapor vacuum arc (MEVVA) ion implantation technology was applied to implant the silver on the surface of TiNb-based alloy, which brought the change of the microstructures and mechanical properties for the surface of substrate. It was found that the diffusely distributed silver nanoparticles generated on the outermost surface of the implanted layer and the Ag element exist as a solid-solution state in the implanted layer. Meanwhile, the region of the implanted layer mainly constituted nanocrystalline structures based on the analyses of microstructures. Hence, the nanocrystalline strengthening effect formed by high-energy ion bombardment and the solid solution strengthening effect of silver atoms made contributions to the increase of surface comprehensive mechanical properties, including the surface hardness and elastic modulus. Finally, the suitable Ag-implanted specimen can obtain excellent antibacterial ability. Except for the antibacterial mechanism of silver ions release, the dispersed silver nanoparticles on the surface also provide the contact antimicrobial mechanism, which is the Schottky barrier–dependent antimicrobial efficacy of silver nanoparticles.