铝合金阳极在碱性介质中的电化学性能

介绍了两种Al Pb In Ga X(X为Mg、Sn)系新型铝合金阳极材料 ;用恒电流方法和动电位方法研究了新型合金阳极在碱性氯化钠介质中的电化学性能 ,分析了介质 pH值、介质温度、极化电流密度对电极电位的影响 ;用金相显微镜、扫描电子显微技术观察了铝合金的微观组织和阳极溶解后的表面腐蚀状态。结果表明 :新型铝合金阳极材料开路电位较纯铝稍低 ;自腐蚀速率急剧降低、电极表面腐蚀溶解均匀 ;新型铝合金在碱性氯化钠介质中不能形成钝化膜 ,阳极极化明显减少 ;在碱性氯化钠 (2 5 %KOH 3 .5 %NaCl)介质中大电流密度 (80 0mA/cm2 )下新型合金阳极材料 (1# 、2 # )的稳定电极电位可分别达到 -1.3 5V、-1.45V (vs .Hg/HgO)。

Electrochemical properties of anodes based on Al alloys in alkaline medium

Neoteric anode materials based on Al Pb In Ga alloys were introduced. Their electrochemical properties in alkaline medium were studied by means of constant current and dynamic potential methods. The pH value and temperature of the medium were also analyzed as well as the effect of current density for polarization on electrode potential. Moreover, the microstructure of Al alloys and the surface corrosion of anode after dissolution were observed by metallurgical microscope and scanning electron microscope (SEM) techniques. The results show that the open circuit potential of the neoteric Al alloys are lower than that of pure (99.99% purity) Al. Their self corrosion rate is decreased rapidly and the surface corrosion of electrode is dissolved evenly. The passive film can not be formed onto neoteric Al alloys in alkaline medium and the anode polarization is reduced obviously. The stable potential (vs. Hg/HgO) of anode materials based on the neoteric Al alloys is -1.35 V and -1.45 V respectively when they are in the alkaline NaCl (25% KOH 3.5% NaCl) medium.