Corrosion behavior of plasma electrolytic oxidation coatings in simulated body fluid (SBF) at silicate and calcium phosphate electrolytes

The effect of plasma electrolytic oxidation (PEO) pre-treatments on corrosion behavior of titanium in simulated body fluid (SBF) is investigated. Three-pre-treatments are compared,using silicate, calcium phosphate and mixed of silicate and calcium phosphate (1:1) respectively, which result in different composition and morphologies of coatings. The resultantcoatings were examined by high resolution field emission scanning electron microscopy(FESEM) equipped with energy dispersive spectrometer (EDS) and X-ray diffraction. The PEO- treated specimens revealed distribution of coating species, mainly the titanium-rich inner coating region. However, findings show highly localized variations in composition within theircrystalline structures, due to the melting and rapid solidification of the coating material in three different electrolytes. Corrosion behavior of the coatings was also examined in simulated bodyfluid (SBF) in 37 ºC by potentiodynamic polarization, revealing an improved corrosion resistance for mixed electrolyte in comparison with silicate and calcium phosphate electrolytes

Keywords:

Plasma Electrolytic Oxidation (PEO) , mixed electrolyte , corrosion resistance , SBF