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.