Enhancement of adhesion strength and tribological performance of pure carbon coatings on Ti-6Al-4V biomaterials with ion implantation pre-treatments

A novel method to increase the adhesion strength of pure carbon coatings on Ti-6Al-4V biomaterials is reported. In the early stage of the experiment, ion implantation of carbon was carried out by metal vapour vacuum arc (MEVVA) in order to create a gradient composition interlayer in the Ti-6Al-4V substrate for subsequent coating depositions. The pure carbon coatings were deposited in a closed-field unbalanced magnetron sputtering system. It was found that the coatings prepared on the carbon-implanted substrates could provide a significant enhancement of adhesion strength, impact and wear resistance. The greatly increased performance could be explained by the increase in hardness of the carbon-implanted substrate and the formation of Ti-C bonds.