Corrosion of Titanium Biomaterials, Mechanisms, Effects and Modelisation

ABSTRACT The in vitro and in vivo research results show very low corrosion rate of Ti bioalloys. Among different sources of corrosion, the general and localized corrosion in vitro and fretting corrosion in vivo are the most expected degradation processes. Three possible mechanisms of dissolution of Ti biomaterials include: dissolution of titania layer, diffusion of elements through the oxide layer, electrochemical reaction in corrosive environment of the bare metal inside the damaged layer. The corrosion processes result in deterioration of human body by corrosion products followed by loosening of implant and possible serious diseases. The standard research techniques are inadequate as regards the assessment of long-term corrosion, localized corrosion of porous materials and dissolution of oxide layer. The further research is necessary to estimate the critical steps allowing for metals dissolution and optimization by physical modelisation and treatment by mathematical techniques, especially fuzzy logic and neural networks.