Experimental Study On The Mechanical Properties,Corrosion Properties And Antibacterial Properties Of Ti-3Cu Alloy

Titanium and titanium alloys have been widely used in the biomedical implant field due to their excellent mechanical properties and biocompatibility,especially in repair and replacement materials such as artificial joint and dental implants.But one of the big problems that plague the doctor is the infection or the inflammation.Once the infection occurs,it will seriously affect the healing process.Patients sometimes need to accept long-term antibiotic treatment even re-operation.Thus,the implant with strong antibacterial properties shows great potential for medical implant materials in clinic application.Previous study has shown that Ti-3Cu alloy(As-cast)has good antibacterial properties but the mechanical properties still need to be improved.In this paper,a series of heat-treatment processes were selected to improve the mechanical properties of wrought Ti-3Cu alloy without reduction in the antibacterial properties.The effect of heat-treatment on the microstructure,mechanical properties,corrosion resistance and antibacterial properties has been systematically investigated by X-ray diffraction(XRD),optical microscope(OM),scanning electron microscope(SEM),transmission electron microscopy(TEM),electrochemical measurements,tensile test,fatigue test and antibacterial test.It has been shown that heat treatment could improve significantly the mechanical properties,corrosion resistance and antibacterial rate.T4 treatment increased the yield strength from 400 MPa to 740MPa and improved the antibacterial rate from 33%to 65.2%while T6 treatment enhanced the yield strength to 800-850MPa and the antibacterial rate>91.3%.It was demonstrated that homogeneous distribution and fine Ti2Cu phase played a very important role on mechanical prop erties,corrosion resistance and antibacterial properties.Electrochemical experiments showed that cp-Ti and Ti-3Cualloys exhibited higher icorr and lower Rp in Saliva-pH3.5 and Saliva-pH6.8+0.2F solutions,indicating that pH and F ion significantly reduced the corrosion resistance of titanium alloys.Compared with the static electrochemical experiment,the open circuit potential Eocp became significantly negative under frictional environment,and the icorr of the material obviously increased.It can be found that wrought Ti-3Cu has similar corrosion and wear properties to cp-Ti,but Ti-3Cu(T6)shows better wear resistance and corrosion resistance with much lower wear rate and corrosion current density.Ti-3Cu(T6)alloy,as a new type of bio-metallic material,has a strong antibacterial ability compared with cp-Ti,high yield strength,excellent fatigue resistance and good corrosion-wear property in simulated body fluids,which showing great potential for growth in biomedical applications.