Pure titanium and Ti-6Al-4V are the earliest titanium and titanium alloy materials used in clinical applications and represent the first generation of biomedical titanium alloys. In the early 1940s, pure titanium was introduced into the field of biomedical science, and its rapid development as a medical material was witnessed after its use in dental implants in the 1960s.
Ti-6Al-4V titanium alloy is the most widely produced and applied titanium alloy, known for its high strength and excellent processability. It has been used since the 1970s in areas such as hip and knee joints that require high strength and wear resistance. However, with further research and application, a large number of experiments and data have confirmed the toxic side effects of vanadium on the human body.
The research team at the Institute of Metals, Chinese Academy of Sciences, has developed a new type of low-modulus β-type medical titanium alloy, Ti2448, and so on. By optimizing the content of β-stabilizing elements and controlling the alloy's microstructure and β-phase stability through thermomechanical processing, the researchers can regulate crucial performance characteristics such as elastic modulus and strength within a wide range.
Functionalization is another important development direction for new medical titanium alloys, with in-depth research on antibacterial titanium alloys. As a type of biologically inert material, titanium alloys do not possess inherent antibacterial or bacteriostatic properties. However, during the implantation process, harmful bacteria may be introduced, leading to infections, and in severe cases, implant failure. By adding alloying elements such as copper (Cu) and silver (Ag) in appropriate amounts to titanium alloys, the alloys can exhibit certain antibacterial effects while maintaining their basic mechanical properties.
In addition, researchers have developed a series of copper-containing medical titanium alloys. When the copper content in the alloy exceeds 5%, the released copper ions can achieve sufficient and stable antibacterial properties against Staphylococcus aureus and Escherichia coli. Moreover, the cumulative release concentration of copper ions is much lower than the WHO's recommended daily copper intake, indicating that Ti-5Cu exhibits good biocompatibility.
Furthermore, these advancements in the field of titanium alloys for hard tissue implants offer new prospects. In the future, these innovative materials and functional designs will provide safer and more reliable solutions for the medical field.
