Study on mechanical behavior of Cu-bearing antibacterial titanium alloy implant

Cu-bearing titanium alloy has been proved to have excellent antibacterial properties, which can effectively reduce the incidence of infection caused by implantation. On the other hand, the addition of Cu in the titanium alloy can also significantly improve the strength of the alloy due to the dispersed precipitation of Ti₂Cu compounds in matrix, which will enhance the biomechanical safety of Cu-bearing antibacterial titanium alloys. In this study, a Ti6Al4V5Cu antibacterial titanium alloy and the ordinary Ti6Al4V titanium alloy were used to make a variety of orthopedic trauma repair implants, including bone pin, bone screw and bone plate. Through the internationally accepted test methods, the mechanical properties such as tension, torsion and bending of the implants were studied, and the difference between the implants made of two materials was analyzed. The results showed that the tensile strength of Ti6Al4V5Cu pin was 25% higher than that of Ti6Al4V pin, the torsion strength of the screw was increased up to 89%, the static bending load of the plate was increased by 67-89%, and the maximum loading force of the plate after 1 million cycles of four point dynamic bending was increased by 41-91%. The above improvements should be attributed to the strengthening effect of Cu in the antibacterial titanium alloy, indicating that the Cu-bearing antibacterial titanium alloy implant possesses both advantages of reducing the bacterial infection and improving the biomechanical safety, and a broad clinical application prospects.