Effects of carbon ion pre-implantation on the mechanical properties of ta-C coatings on Ti-6Al-4V

We report on our investigations of the effects of carbon ion implantation into Ti-6Al-4V as a pre-treatment process prior to deposition of ta-C coatings using a filtered cathodic arc plasma method. A transition layer is formed that can be either TiC or TiC+C, providing an excellent interface for highly adherent ta-C coatings. We find that a smoothly-graded interface leads to good film–substrate adhesion, while ta-C films formed without a graded interface show poor adhesion. The film microhardness and wear performance are related to the implantation parameters via the thickness of the transition layer. Carbon ion implantation provides an effective pre-treatment method for ta-C coated Ti-6Al-4V substrate material.