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.