Nitridation processes of titanium for biomedical protheses
Abstract
Titanium and some its alloys represent the better metallic materials with high biocompatibility useful to realise many biomedical prostheses and implants. Special fix and movable titanium based prostheses are found in Dentistry and Orthopaedy, such as dental implants, knee and hip articulation anchorages.
The functionality and the average lifetime of such devices can be improved by the nitridation processes of titanium. The nitridation increases the mechanical strength and the chemical inertia and reduces the surface wear of the material.
Thermal nitridations of Ti and Ti-6AI-4V alloys have been performed at temperatures between 300°C and 100 °C as a function of the time. Moreover, the ion implantation of nitrogen ions at 100-300 keV energy and high doses, up to about 107 ions/cm2, followed by thermal annealing at 500 °C, has been employed with success to reduce the surface wear and friction of movable prostheses and to increase their biocompatibility. Treated surfaces have been characterised by different physical analysis techniques, such as AES, XRD, RBS and SEM.
