(Zr,Ti)CN coatings as potential candidates for biomedical applications

(Zr,Ti)CN hard coatings, deposited by DC magnetron sputtering on Ti6Al4V alloy and Si substrates, were investigated as possible candidates to be used as protective layers for medical implants. Two coating types, with different non-metal/metal ratios, were prepared. The films were analyzed for elemental and phase composition, crystallographic structure, mechanical properties, corrosion behavior, surface wettability and cell viability. The coatings were found to have composite structures, in which a (Zr,Ti)CN crystalline phase coexists with an amorphous a-C(N) one. Film thickness and hardness in the ranges 1.8-2.1 mu m and 25-29 GPa, respectively, were measured. The coated samples exhibited an improved corrosion resistance as compared with the Ti6Al4V alloy. Both coating types were found to be hydrophobic, the contact angles being higher than 100 degrees. Cell viability measurements proved that the osteosarcoma cells are adherent to the coating surface, the highest viability (90.5%) after one week incubation being found for the film with high non-metal content. (C) 2011 Elsevier B.V. All rights reserved.