The effect of surface preparation on the protective properties of Al2O3 and HfO2 thin films deposited on cp-titanium by atomic layer deposition

Atomic layer deposition (ALD), a method that allows the formation of thin and conformal films on substrates interest, was employed to prepare alumina (Al2O3) hafnia (HfO2), with aim protecting surface commercially pure titanium (cp-Ti) used in biomedical applications. Prior deposition, cp-Ti specimens have been prepared two ways – grinding followed by polishing. Such surfaces denoted as rough smooth, respectively. The thickness, composition, morphology topography determined using ellipsometry, focused ion beam microscopy energy dispersive X-ray spectroscopy, time-of-flight secondary mass spectrometry 3D profilometry. A homogeneous stoichiometric composition obtained thickness ca. 150 nm. anti-corrosive properties ALD were measured simulated body fluid solution, electrochemical impedance spectroscopy (EIS) potentiodynamic polarization curves. roughness plays an important role protective these films, especially those hafnia. In general, when deposited smooth surface, better obtained, evidenced EIS long-term, 40-day tests. showed very low porosity, calculated from parameters, significantly lower corrosion current densities, compared bare specimens. Lower porosity slightly provided On other hand, according long-term tests, retained greater values than Since both are biocompatible materials, this study confirms possibility their use reduce risk failure medical implants made cp-Ti, human environment.