中文摘要：

采用熔炼铸造法制备Mg-6%Al-5%Pb（质量分数,下同）阳极材料,采用金相显微镜（OM）观察不同热处理状态下Mg-6%Al-5%Pb阳极材料的显微组织,采用X射线衍射仪（XRD）分析Mg-6%Al-5%Pb阳极材料的相结构,采用电化学方法和化学浸泡法研究Mg-6%Al-5%Pb阳极材料在3.5%Na Cl溶液中的腐蚀行为,采用扫描电镜（SEM）观察浸泡不同时间后Mg-6%Al-5%Pb阳极材料的腐蚀表面形貌。结果表明：Mg-6%Al-5%Pb阳极材料在浸泡初期的腐蚀存在孕育期,孕育期内腐蚀速率较小。随着浸泡时间的延长,腐蚀逐渐进入稳态,腐蚀速率增大、趋于恒定。铸态试样的腐蚀以电偶腐蚀的形式从第二相Mg17Al12的周围开始,第二相能减小Mg-6%Al-5%Pb阳极材料的腐蚀速率,但局部腐蚀严重。400℃固溶24 h后腐蚀以点蚀的形式从晶界处开始,腐蚀速率相比铸态试样大,但腐蚀相对铸态试样均匀。

英文摘要：

Mg-6% Al-5% Pb （mass fraction） anode materials were prepared by melting and casting. The microstructures of Mg-6% Al-5% Pb anodes under different heat treatment conditions were observed by optical microscopy （OM）. The phase structures of Mg-6%Al-5%Pb anodes were analyzed by X-ray diffraction （XRD） and the corrosion behaviors of Mg-6% Al-5% Pb anodes in 3.5% NaCI solution were studied by electrochemical measurements and immersion tests. The corroded surfaces of Mg-6%Al-5%Pb anodes after various periods of immersion were observed by scanning electronic microscopy （SEM）. The results show that there is an incubation period at the corrosion onset, with the low corrosion rate. Thereafter the corrosion rate increases as the increase of immersion time and gradually comes into steady state. For as-cast specimens, the galvanic corrosion initiates surrounding the second phases （Mg17Al12）. The second phases can reduce the corrosion rate of the Mg-6%Al-5%Pb anode, while accelerate the local corrosion. After solid solution treatment at 400 ℃ for 24 h, the corrosion of the Mg-6%Al-5%Pb anode initiates along the grain boundaries in the form of pitting corrosion and the corrosion rate is higher than that of as-cast specimen, but the corrosion develops homogeneously on the specimen surface.