B Major, R Ebner, T Wierzchon, W Mroz, W Waldhauser, R Major, M Wozniak
Ann Transplant 2004; 9(1A): 30-34
Successful application of titanium and its alloys in medicine is related to its promising behavior in trauma treatment due to biocompatibility and corrosion resistance. Titanium nitride (TiN) is regarded as a potential biomaterial for blood-contact applications. Titanium nitride thin layers were produced by pulsed laser deposition (PLD) performed with a Nd: YAG laser on two types of biomaterials, metallic titanium and polyurethane. The formation of a uniform smooth surface was observed in both cases. The application of scanning electron microscopy (SEM) in the examination of the material cross-section revealed a form of diffusion layer, with continuous transfer between the deposited film and the substrate. Transmission electron microscopy (TEM) examinations of thin foils, prepared from a metallic titanium cross-section covered with TiN, confirmed the diffusive character of the deposited layer. Moreover, the deposited TiN phase was found to have a fine grained microstructure. Texture examinations were carried out for both deposited TiN and the titanium substrate. The application of the pseudo-position sensitive detector in texture examination allowed to draw the pole figures of residual stresses, while X-ray diffraction used for residual stress measurement (sin2Psi) made it possible to measure their values. The latter were found to fall for the TiN phase into the range between -8 and -10 GPa for films produced on the metallic titanium substrate, and -4 to -5 GPa for the polyurethane substrate. The morphology of the surface of the deposited layers was examined by means of atomic force microscopy (AFM). The results revealed a contribution of the deposition parameters and the layer thickness to crystallite sizes and vertical diameter.
Keywords: Deposition, Titanium Nitride, Biocompatibility