The influence of plasma-sprayed coatings on surface properties and corrosion resistance of 316L stainless steel for possible implant application

Abstract

AbstractHerein, we analyzed the morphology of atmospheric plasma-sprayed (APS) coating on medical 316L stainless steel and its influence on the physical and electrochemical properties of implant application. Five types of coatings were examined: hydroxyapatite (HAp), titanium (Ti), zirconium (Zr), Ti/HAp and Zr/HAp. The base properties of the coatings were analyzed via chemical and phase composition, surface topography, surface wettability and in particular the corrosion resistance in Ringer solution in immersed conditions and potentiodynamic test, and EIS analysis. APS coating of pure HAp on 316L stainless steel showed poor cohesive bonding to the substrate material, whereas the application of Ti and Zr interlayer prior to HAp deposition improved surface morphology and coating properties. The beneficial effect of Ti and Zr interlayer under HAp layer on binding was demonstrated. HAp containing coatings (HAp, Ti/HAp and Zr/HAp) show Ca/P ratio greater than 1.8, which may positively influence the differentiation of osteogenic cells and good adhesion to bones. Among the studied materials, the composite coatings with Zr or Zr/HAp showed favorable physicochemical properties and the highest corrosion resistance in Ringer solution.