Electrochemical corrosion behavior of biodegradable Mg–Y–RE and Mg–Zn–Zr alloys in Ringer’s solution and simulated body fluid

• WE43 offers better corrosion resistance than ZK60 in simulated body fluid (SBF).
• Calcium phosphate is formed on the 96 h immersed WE43 and ZK60 Mg alloy in SBF.
• Aragonite form of CaCO3 is formed on the 96 h immersed samples in Ringer’s solution.
• At 1 h both Mg alloys offers smaller resistance, RP in SBF than in Ringer’s solution.
• In contrast to WE43, ZK60 shows localized and pitting corrosion in both solutions but WE43 not.

The corrosion behavior of WE43 and ZK60 Mg alloys are investigated in Ringer’s solution and simulated body fluid (SBF). The major protective corrosion-products formed on both Mg alloys are crystalline aragonite form of CaCO3 and Mg(OH)2 in Ringer’s solution whereas Ca10(PO4)6(OH)2, Ca3(PO4)2⋅3H2O and Mg(OH)2 in SBF. Electrochemical impedance spectroscopy reveals that in the initial stage, the increase in the corrosion resistance on both Mg alloys in Ringer’s solution is more than 6 times than in SBF. Our study reveals higher RP, larger impedance, and bigger phase angle maxima for WE43 than ZK60 after immersion in both solutions for 96 h.