Preparation Of Antibacterial Ti-Cu Alloys And The Study On The Microstructure And Antibacterial Properties

Titanium and titanium alloys have been widely used in the medical field due to their excellent biocompatibility,especially in repair and replacement materials for implanting such as artificial joint and dental implants,etc.However,the clinical infection and in vivo corrosion always lead to implants loosening even implantation failure.In this paper,Cu element was selected as an antibacterial agent to develop a new biomedical Ti-Cu alloy with different Cu contents and different existing forms of Cu by casting,forging and heat-treatment.In order to explore the effect of Cu content and heat-treatment on the microstructure,mechanical properties,corrosion resistance and antibacterial properties of Ti-Cu alloys,samples have been systematically investigated by X-ray diffraction,optical microscope,scanning electron microscope(SEM),transmission electron microscopy(TEM),electrochemical measurement,compressive test and antibacterial test.Following results were obtained:The microstructure observation shows that the as-cast Ti-xCu alloy was mainly composed of lamellar microstructure,consisting of a phase and Ti2Cu phase.After solid solution treatment,Cu completely dissolved in the matrix and the matrix becomes martensite basket-like structure.After aging treatment,Ti2Cu phase precipitated from the matrix and distributed homogeneously.The mechanical properties,corrosion resistance and antibacterial properties of Ti-xCu alloys was greatly improved after heat treatment,especially after the aging treatment.Besides,the corrosion resistance and antibacterial properties of Ti-xCu alloys also gradually increased with the increase of Cu content.The forged Ti-3Cu alloy with lamellar microstructure consisted of ? phase and Ti2Cu phase.After solid solution treatment,the microstructure of the alloy changed to needle-like martensite.After aging treatment,Ti2Cu phase precipitated from the matrix and distributed homogeneously,and changed from spherical shape to ribbon shape with the extension of the aging time.The tensile strength and antibacterial property of the alloy increased with the aging time,but the plasticity of the alloy decreased obviously after the secondary aging treatment.The antibacterial tests results show that only the aged Ti-Cu alloy with>2%Cu exhibited stable antibacterial property while the as-cast Ti-Cu alloy had no antibacterial property.It is inferred that the antibacterial property of Ti-Cu alloy is related not only to Ti2Cu phase but also to the size and the distribution.