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,...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.展开更多
An Mg-Zn-Mn-Ca alloy with high Zn content was fabricated by vacuum melting. The as-cast microstructure was investigated using XRD, SEM and EDS. It was shown that the alloy was composed of α-Mg, strip-like Ca2Mg6Zn3 a...An Mg-Zn-Mn-Ca alloy with high Zn content was fabricated by vacuum melting. The as-cast microstructure was investigated using XRD, SEM and EDS. It was shown that the alloy was composed of α-Mg, strip-like Ca2Mg6Zn3 and a few Mn- containing phases. Most of the Ca2Mg6Zn3 phase was distributed at grain boundaries while Mn-containing particles were deposited within grains. The as-cast samples were immersed in a Hank＇s balanced salt solution （HBSS） up to 24 h. The corroded surface morphology and cross-section microstructure were analyzed after different time of immersion so as to understand the corrosion behavior of the alloy. During immersion in the HBSS, the alloy corroded homogeneously at the very beginning and then localized corrosion occurred. The secondary phases protruded on the surface due to the dissolution of α-Mg, suggesting micro- galvanic corrosion occurred with secondary phases acting as the cathode and ct-Mg as the anode. Micro-cracks were formed at the interfaces between Ca2Mg6Zn3 and α-Mg, indicating an undermining tendency of the secondary phases.展开更多
文摘采用浸泡实验、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.
文摘An Mg-Zn-Mn-Ca alloy with high Zn content was fabricated by vacuum melting. The as-cast microstructure was investigated using XRD, SEM and EDS. It was shown that the alloy was composed of α-Mg, strip-like Ca2Mg6Zn3 and a few Mn- containing phases. Most of the Ca2Mg6Zn3 phase was distributed at grain boundaries while Mn-containing particles were deposited within grains. The as-cast samples were immersed in a Hank＇s balanced salt solution （HBSS） up to 24 h. The corroded surface morphology and cross-section microstructure were analyzed after different time of immersion so as to understand the corrosion behavior of the alloy. During immersion in the HBSS, the alloy corroded homogeneously at the very beginning and then localized corrosion occurred. The secondary phases protruded on the surface due to the dissolution of α-Mg, suggesting micro- galvanic corrosion occurred with secondary phases acting as the cathode and ct-Mg as the anode. Micro-cracks were formed at the interfaces between Ca2Mg6Zn3 and α-Mg, indicating an undermining tendency of the secondary phases.
