Ion implantation of oxygen and nitrogen in CpTi

A study of the plasma ion implantation (PIII) of commercially pure titanium (CpTi) at a low voltage (<4 kV) is presented. The processed samples were treated in divers mixtures of O and N in order to achieve biocompatible oxidized and nitrided layers as well as to enhance their superficial hardness. In this way, the low wearing resistance of CpTi can be avoided while creating a biocompatible rutile phase titanium oxide layer for a better bone integration. A form of synergy associated to the dependence of microhardness on the implanted layer disposition is identified. Thus, an upper rutile layer is immediately followed by another one, in which titanium, a nitride (TiN0.26) and rutile coexist. The latter leads to a superior microhardness performance. Most of all these surface treatments of titanium, when applying an 80%N-20%O mixture, yield higher corrosion resistance parameters with respect to the main metallic materials used in prosthetics, including the Co-Cr-Mo alloys, albeit excluding CpTi.