摘要
Mg-Al-Pb alloy is a good candidate for the anode material of magnesium seawater battery. For improving the low current utilization efficiency of Mg-Al-Pb alloy, the influence of Ce on the microstructures and electrochemical corrosion properties in a 3.5% NaCl solution was investigated using scanning electron microscope and electrochemical measurements. The results indicate that Ce refines the grain structure of Mg-Al-Pb alloy. The formation of strip Al11Ce3 second phase promotes the uniform distribution of Mg17Al12 phase in Mg-Al-Pb-Ce alloy. The addition of cerium accelerates the discharge activity of Mg-Al-Pb alloy. Due to a large number of cathodic Al11Ce3 and MglyAla2 phases, Ce promotes the micro-galvanic corrosion and leads to larger corrosion current density and hydrogen evolution rate in Mg-Al-Pb-Ce alloy than those in Mg-Al-Pb alloy. However, Mg-Al-Pb alloy expresses smaller utilization efficiency than Mg-Al-Pb-Ce alloy because of grain detachment.
Mg-Al-Pb合金是一种应用于海水激活电池的镁阳极材料。为提高Mg-Al-Pb合金的电流效率,通过扫描电子显微镜和电化学测试方法研究Ce对Mg-Al-Pb合金显微组织和腐蚀电化学性能的影响。结果表明,Ce元素促进了条状第二相Al_(11)Ce_3的析出,使Mg_(17)Al_(12)相在Mg-Al-Pb-Ce合金中分布更均匀,并细化了合金的显微组织。Ce的添加提高了Mg-Al-Pb合金的放电活性,大量的第二相Al_(11)Ce_3和Mg_(17)Al_(12)使合金的微电偶腐蚀增强,从而导致Mg-Al-Pb-Ce合金具有较大的腐蚀电流密度和析氢速率。放电过程中Mg-Al-Pb合金存在晶粒脱落,相比之下,Mg-Al-Pb-Ce合金具有更大的电流效率。
基金
Project(2015JC3004)supported by Science and Technology Plan Projects of Hunan Province,China
Project(51401243)supported by the National Natural Science Foundation of China
