The correlation between substrate and deposited biocompatible layer microstructures on different substrates

The biocompatibility is essential for the so called biomaterials used for medical devices (e.g. artificial implants, implants). It is determined mainly by the surface chemical composition and the environment in which the implant is used. The implant materials used till the date have limited biocompatibility. On the other hand newly developed biocompatible materials are usually more expensive. The biocompatibility of currently used materials can be improved via deposition of thin biocompatible layer on the substrate. This layer may be further improved (or used as interlayer) introducing hydroxyapatite, BaTiO3 or other surface treatments. The microstructure of deposited layers has to be known in such cases as it can influence properties of the surface. Various substrates (pure titanium, Ti6Al4V alloy and Ti-39Nb alloy) were used for biocompatible Ti-39Nb layer sputtering deposition in current paper. The microstructure of substrates has been characterized using electron microscopy techniques. The correlation between substrate and layer microstructures could have been revealed, because both microstructures were studied at the same area of the substrate. Significant differences in grain size have been observed on various substrates. Also the microstructure of deposited layer can be distinguished into two types. These are pure β-Ti phase probably on the grains where the surface diffusivity is high enough (locally observed on Ti-39Nb and pure Ti substrates) and mixture of α″ martensitic and β-Ti phase columns.