Research Progress on Surface Modification of Biomedical Titanium Alloys to Improve Wear Resistance Performance

Titanium and its alloys are the most commonly used medical implant metal materials in orthopedics and dentistry, as they possess low density, high strength, non-toxicity, and excellent corrosion resistance. Compared with traditional stainless steel and cobalt-based alloys, titanium alloys have a lower elastic modulus, and the low elastic modulus has been proven to reduce the stress shielding effect, thereby better inducing and promoting bone integration. These advantages make them more suitable for clinical medical applications.

However, titanium and its alloys cannot meet the clinical requirements of biomedical implants. Long-term clinical research observations have found that titanium implants have poor wear resistance, and the wear debris generated by the friction of titanium implants can cause inflammatory problems and toxic effects on the human body.

To improve the biological and tribological properties of titanium alloys, introducing surface modification techniques to enhance the bioactivity, wear resistance, and antibacterial properties of titanium and titanium alloys is a more economical and effective method to improve existing conventional biomaterials to meet current and evolving clinical needs. Currently, various physical and chemical methods have been adopted to improve the wear performance of titanium alloys. By depositing a layer of ceramic coating with excellent wear resistance on the titanium surface, the wear and corrosion performance of the titanium and titanium alloy can be improved. Common wear coatings include diamond-like carbon films (DLC), titanium nitride (TiN), etc.

Diamond-like carbon film (DLC)Br> Due to its high hardness, excellent wear resistance, low friction coefficient, and good biocompatibility, the diamond-like carbon film is often used as a wear-resistant coating in medical metal implants. Some implant devices modified by surface treatment with diamond-like carbon films have already achieved clinical application, and have broad application prospects in improving the wear and corrosion resistance of metal components of artificial joints.

Titanium nitride (TiN)

TiN has good wear resistance and corrosion resistance. It was initially used in cutting tools to extend their service life, and later it was found to have biocompatibility and began to be used in medical implants, such as plastic surgery and dentures. Currently, the main methods for preparing titanium nitride are physical vapor deposition (PVD), chemical vapor deposition (CVD), and thermal spraying.