Corrosion resistance of N-implanted pure iron in simulated body fluids

Pure iron specimens were implanted by nitrogen ions with a fluence of 7×1017 ions/cm2 using ion beam implantation at an extracted voltage of 40kV.Composition and valence studies were carried out by X-ray photoemission spectroscopy(XPS);Glancing angle X-ray diffraction(GAXRD) was employed to examine the phase transformation.The corrosion behavior of the samples was measured using potentiostatic polarization curves(E/I) in simulated body fluids(SBF) solution.The results have demonstrated that the surface corrosion resistance of nitrogen ion implanted samples can be improved in SBF solution. The analyses of XPS and XRD have shown that,after nitrogen ion implantation,the iron nitride of γ′-Fe4N were formed on the implanted surface,and effectively improved the surface corrosion resistance.