An investigation of the corrosion mechanisms of WE43 Mg alloy in a modified simulated body fluid solution: The effect of electrolyte renewal

• The effect of daily electrolyte renewal on the corrosion process is investigated.
• The time-dependent behaviour of impedance parameters is analysed.
• Electrolyte renewal allows for better control of pH and electrolyte components.
• Corrosion rates obtained by EIS, H2 evolution and ICP-OES show a good agreement.
• Electrolyte renewal delays barrier film coverage and onset of localized corrosion.

The effect of daily electrolyte renewal on the corrosion mechanisms and kinetics of WE43 Mg alloy in a modified simulated body fluid (m-SBF) is investigated by electrochemical, hydrogen evolution, analytical and surface characterization techniques. It is shown that by performing electrolyte renewal, physiological control of corrosion products and concentration of relevant electrolyte components such as calcium, phosphate and carbonate species, can be better emulated. Electrolyte renewal affects the corrosion mechanism by promoting partial dissolution of the corrosion layer and increasing mass transport, thereby delaying the increase in the corrosion layer protective ability and the occurrence of localized corrosion.