中文摘要：

利用扫描电镜（SEM）、X射线衍射（XRD）分析稀土元素La对Mg-Hg-Ga阳极材料显微组织的影响，并采用恒电流放电、动电位极化扫描、交流阻抗法、阳极效率测试和化学浸泡法研究La对Mg-Hg-Ga阳极材料腐蚀电化学性能的影响。结果表明：La的添加能使Mg-Hg-Ga合金晶粒细化，大量的Mg17La2和LaHg6相聚集在晶界处呈网状分布。随着La含量的升高，合金电化学活性下降，耐腐蚀性能先降低后增加，阳极效率先下降后升高，Mg-Hg-Ga-2％La合金的析氢速率为17．92mL／（cm2·h），阳极效率为50．3％；而Mg-Hg-Ga-6％La合金的析氢速率仅为0．45mL／（cm2·h），阳极效率为82．5％。这是因为随着La含量的升高，合金中新增的Mg17La2和LaHg6相为弱阴极性相，与a-Mg之间形成的腐蚀原电池驱动力较小，从而抑制镁基体的腐蚀。

英文摘要：

The effect of La on the microstructure of Mg-Hg-Ga anodes was analyzed by scanning electronic microscopy（SEM） and X-ray diffractometry（XRD）. The effect of La on electrochemical performance of Mg-Hg-Ga anodes was investigated by potentiodynamic polarization, galvanostatic test, electrochemical impedance spectroscopy, anodic efficiency test and chemical immersion method. The results show that the La addition can refine the grain of Mg-Hg-Ga alloy, large amounts of Mg17La2 and LaHg6 phases accumulate in grain boundary and distribute reticularly. The electrochemical activity of alloys declines with the increase of La content, while the corrosion resistance and anodic efficiency firstly reduce and then increase. The H2 evolution rate of Mg-Hg-Ga-2%La alloy is 17.92 mL/（cm2·h） and the anodic efficiency is 50.3%. While the H2 evolution rate of Mg-Hg-Ga-6%La is 0.45 mL/（cm2·h） and the anodic efficiency is 82.5%. The reason is that the newly formed Mg17La2 and LaHg6 phases are weakly cathodic phase with the increase of La content. The driving force of the corrosion cell forming between these phases and a-Mg is small, which will inhibit the corrosion of Mg matrix.