Influence of the carbon content on the corrosion and tribocorrosion performance of Ti-DLC coatings for biomedical alloys

• Three DLC coatings were deposited on Ti grade 5 by changing PVD process parameters.
• Different process parameters provide different tribo-chemical response.
• Three DLC coatings have excellent corrosion response and electrochemical stability.
• DLC coatings reduced friction by 64%.
• Coatings strongly decrease the wear rates due to tribocorrosion by 98–100%.

Biomedical alloys are prone to suffer corrosion and wear phenomena coming from the hostile environment of the body and friction processes, respectively. Diamond-like carbon (DLC) coatings are known to be excellent candidates for using as protective coatings on biomedical alloys, not only due to their excellent tribological properties but also due to their chemical composition and stability. In this work, three Ti-DLC PVD coatings with different compositions were deposited on Ti6Al4V alloy and their corrosion and tribocorrosion responses were evaluated in simulated body fluid. Excellent tribocorrosion response has been found especially in case of coatings with high carbon content. Additionally significative reduction of friction and wear has been obtained in comparison to the substrate response.