Degradation behaviour of pure magnesium in simulated body fluids with different concentrations of HCO3-

Corrosion behaviour of pure magnesium in simulated body fluids (SBF) with HCO₃ ^- concentrations of 4, 15 and 27mmol/L is studied. Magnesium is not sensitive to pitting corrosion in all the SBFs. Higher HCO₃ ^- concentration effectively slow down the corrosion rates. Uniform and compact corrosion product layer preferentially forms in SBF with HCO₃ ^- of 27mmol/L. Potentiodynamic polarization test indicates that HCO₃ ^- of 27mmol/L dramatically enhance corrosion potential and induce passivation. EIS results further confirm that higher concentration of HCO₃ ^- induce more effective protection layer, especially in SBF with HCO₃ ^- of 27mmol/L. © 2011 Elsevier Ltd.