Effects of calcium glycerophosphate concentration on micro-arc oxidation coating of Mg alloy

Due to its good biocompatibility and compatible hardness with human bones, magnesium (Mg) alloy is considered as a promising material for bone nails and implants. However, Mg and its alloys are characteristics of active chemical properties and high corrosion rate, which is detrimental to the recovery of patients implanted with Mg alloy bone scaffold. In the present work, to retard the corrosion of the Mg alloy, calcium glycerophosphate (C3H7CaO6P•H2O) was added in the electrolyte to form the micro-arc oxidation (MAO) coatings. Various experimental techniques such as XRD, SEM and EDS have been used to characterize the surface morphology and phase composition of MAO coatings. MAO coatings of different CaP content were studied to explore the synergetic effect between the biocompatibility and corrosive properties by means of electrochemical measurements, hemolysis and pyrogen test. The results showed that higher CaP content can improve the biocompatibility and corrosion resistance while decelerating the hemolysis rate.