Novel electrophoretic deposited nanostructured forsterite coating on 316L stainless steel implants for biocompatibility improvement

• A novel forsterite coating was fabricated by EPD followed by two-step sintering.
• Incorporation of the 0.5 wt% PVA yielded to a uniform forsterite deposition during EPD.
• Coating developed under 25 V for 5 min was crack-free and homogeneous.
• No decomposition of the forsterite coating was observed after two-step sintering.
• Apatite formed on the nanostructured forsterite coating after immersing in SBF.

In this research, a novel nanostructured forsterite coating was deposited on AISI 316L stainless steel substrates by the electrophoretic deposition (EPD) method. Forsterite nanopowders were synthesized using the mechanical activation method. The as-milled nanoparticles were then immersed in a slurry containing 0.5 wt% polyvinyl alcohol (PVA) in order to obtain PVA-coated forsterite nanopowders. The PVA-coated powder particles were electrophoretically deposited on metallic substrates under various conditions (times and voltages). As-deposited coatings were then subjected to a two-step sintering process. The forsterite coatings deposited under different conditions were characterized in terms of microstructural and bioactivity properties. The bioactivity of the prepared specimens was evaluated in simulated body fluid (SBF) at 37 °C for up to 28 days. Results showed that the coating which was deposited after 5 min under a voltage of 25 V was homogeneous and crack-free. The nanostructured forsterite coated samples possessed apatite-formation ability during immersion in SBF.