Fabrication of nanoporous Sr incorporated TiO2 coating on 316L SS: Evaluation of bioactivity and corrosion protection

In this paper, nanoporous TiO2 and Sr-incorporated TiO2 coated 316L SS were prepared by sol–gel methodology. The effect of Sr incorporation into TiO2 coating on bioactivity and corrosion resistance was investigated. Attenuated total reflectance–Fourier transform infrared (ATR–FTIR) spectroscopy, X-ray diffraction analysis (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX) results obtained after in vitro bioactivity test confirm the excellent growth of crystalline hydroxyapatite (HAp) over nanoporous Sr-incorporated TiO2 coated 316L SS which may be attributed to the slow and steady release of Sr ions from the coatings. The electrochemical evaluation of the coatings confirms that Sr-incorporated TiO2 coating offer excellent protection to 316L SS by acting as a barrier layer. The results showed that the incorporation of Sr enhanced both bioactivity and corrosion resistance of 316L SS. Hence Sr-incorporated TiO2 coated 316L SS is a promising material for orthopaedic implant applications.