Corrosion resistance of EPD nanohydroxyapatite coated 316L stainless steel

The effect of nanohydroxyapatite (HA) coating on corrosion resistance of 316L stainless steel was investigated. The stainless steel samples were pretreated in different volume concentrations of H2SO4 solution and were electrophoretically coated for various coating time spans and voltages. The coated samples were sintered in a vacuum furnace at different temperatures to modify the coating structure. The quality and morphology of the pretreated samples and the coating were microscopically characterised, and the compounds presented in the coatings were determined. The electrochemical corrosion test was performed in simulated body fluid to evaluate the coating impact on corrosion behaviour of the samples. The results showed that the deposition of nano-HA using moderate voltage and appropriate time span provides a smooth and almost cracked free coating, improving the corrosion resistance of the samples. Increasing the temperature of sintering modified the HA structure, resulting in the formation of denser coating and enhanced corrosion resistance of the samples.