新型生物可降解Fe-Mn合金在Hanks溶液中的电化学腐蚀行为

Electrochemical Corrosion Behavior of New Biomedical Fe-Mn Alloy In Hanks Solution

采用浸泡实验、阳极极化曲线和电化学交流阻抗(EIS)测试技术,并结合XRD和SEM分析手段对新型生物可降解Fe-Mn合金在37℃人工模拟体液-Hanks溶液中的电化学腐蚀行为进行了研究,并与Fe-C合金比较.研究结果表明:在37℃Hanks溶液中浸泡5天后,Fe-Mn合金表面的腐蚀产物主要为锰的氧化物Mn_3O_4和MnO_2,表面发生均匀腐蚀.Fe-Mn合金在37℃Hanks溶液中的阳极极化行为是活化溶解过程,随着Mn含量由15%增加到30%,合金的自腐蚀电位Ecorr下降,自腐蚀电流密度icorr升高,与Fe-C合金相比,自腐蚀电位Ecorr从-650 m V下降至-800 m V以下,耐蚀性能显著降低.Fe-25Mn合金在37℃Hanks溶液中的容抗弧直径小于Fe-C合金,双电层电荷转移电阻R由420.5Ω·cm2减小为327.0Ω·cm2,降解速度提高.

The electrochemical corrosion behavior of new novel biodegradable Fe -Mn alloys was investigated in Hanks solution at 37~C by potentiodynamic polarization and electrochemical impedance spectroscopy （EIS） techniques, and the corrosion morphology and corrosion product phase structure were analyzed by using video microscope and X ray diffraction techniques. The results show that the corrosion products on Fe -Mn alloys surface are mainly consisted of Mn3O4 and MnOEafter immersion in 37℃ Hanks solution for 5 days. Anodie polarization curves of Fe -Mn alloys show activation and dissolution process in Hanks solution at 37℃. With increasing Mn content from 15 wt% to 30 wt%, the self-corrosion potential Ecorr is decreased, and the self-corrosion current density icoor is increased. Compared with Fe-C alloy, the self-corrosion potential EcorriS decreased from -650 mV to -800 mV, and the resistant R is decreased from 420.5 Ω·cm^2 to 327.0Ω·cm^2. The Fe -Mn alloys has lower polarization resistance and higher degradation rate than Fe -C alloy.