Surface modification of stainless steel implants using nanostructured forsterite (Mg2SiO4) coating for biomaterial applications

The main aim of this research was the preparation of the forsterite (Mg2SiO4) coating on the surface of 316L stainless steel (316L SS) substrate. For this purpose, the nanostructured forsterite was coated on the 316L SS substrate using the sol-gel dip coating technique. Structural characterization techniques including X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDX) were utilized to investigate the phase structure, morphology and elemental composition of the uncoated and coated samples. Corrosion properties of samples were studied using the electrochemical measurements in simulated body fluid (SBF). The in vitro bioactivity evaluation of the forsterite coated samples was conducted by soaking the samples in the SBF at the temperature of 37 °C. The results showed that, a crack-free and homogeneous forsterite coating with the crystallite size of around 40 nm was successfully achieved on the surface of 316L SS substrate. The corrosion current density of the forsterite coated samples was lesser than that of the uncoated ones indicating the improvement of corrosion resistance of the metallic substrate using the forsterite coating. Deposition of Ca and P-contained products on the surface of coated samples during the incubation in the SBF solution confirmed the bioactivity behavior of the forsterite coated samples. Consequently, the 316L SS substrate coated with nanostructured forsterite may be an appropriate selection for dental and orthopedic implant applications.