ScholarWorks@성균관대학교

초록

The corrosion behavior of AZ61 Mg alloy with two different CaO concentrations (0.5 wt% and 1 wt%) was investigated in Ringer's lactate solution at 37 ± 1 °C. Electrochemical characterization techniques, including open-circuit potential (OCP), electrochemical impedance spectroscopy (EIS), and Potentiodynamic polarization (PDP), were employed to assess corrosion kinetics and mechanisms. Additionally, a 10-day immersion test, incorporating hydrogen evolution and weight loss measurements, was conducted to evaluate long-term dissolution resistance. The results demonstrated a clear enhancement in corrosion protection with increasing CaO content. AZ61 Mg alloy exhibited the most negative OCP (-1.370 V) and the highest corrosion current density (225 µA/cm2), corresponding to a corrosion rate of 196 mpy. In contrast, AZ61–1CaO Mg alloy displayed the least negative OCP (-1.260 V) and the lowest corrosion current density (53 µA/cm2), significantly reducing the corrosion rate to approximately 45 mpy. EIS analysis confirmed these findings by revealing larger semicircles and higher charge-transfer resistance for the AZ61–1CaO Mg alloy. Weight loss and hydrogen evolution tests further supported the electrochemical results, indicating that the AZ61–1CaO Mg alloy exhibited the least weight loss, minimal hydrogen evolution, and the most stable and protective corrosion product layer. Biocompatibility analysis (MTT assay, live/dead staining) demonstrated > 80 % cellular viability with low cytotoxicity in all alloys, confirming that CaO addition does not interfere with cell proliferation or morphology.

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