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采用扫描电镜(SEM)和光电子能谱(ESCA)等比较和分析了Al-Zn-In-Si合金牺牲阳极在放电前后的金相结构、表面形态和组成。结果表明:(1)铝合金阳极的金相结构为:在Al-Zn固溶的基体中存在三种偏折相。一种是富集In的颗粒,另二种为聚集在枝晶区的Al-Fe-Si和Al-Fe-Si-In沉积物。(2)铝合金阳极在空气中氧化形成的表面膜,由铝和锌的氧化物组成。在基体和表面氧化膜之间存在金属铟的富集层。(3)放电时铝阳极表面活化溶解,生成的点蚀坑迅速在表面扩展并联成一片。铟偏折相与点蚀引发无关。经深度放电后,表面复盖很厚的氧化铝,其上有金属锌及铟的再沉积层,对保持铝阳极的不断活化溶解可能起重大作用。

Surface sensitive techniques, such as SEM and ESCA, were used for comparing and analyzing the metallurgical structure, surface morphology and composition of Al-Zn-In-Si alloy before and after discharging. ESCA combined with Ar~+ ion sputtering technique was employed for profile analysis of the composition of the oxide film which was formed at the surface of aluminum anode. The measurement results show: (1)The metallurgical structure of Al-Zn-In-Si alloy: There are three kinds of segregative phase which exist in Al-Zn solid solution matrix, One is rich in In. The other two are Al-Fe-Si and Al-Fe-In-Si precipitates which are situated in interdendritic region. (2) The surface film of Al alloy anode formed in the air, is mainly composed of aluminum and zinc oxide. A thin layer of indium was found between the oxide film and the matrix. (3)When discharging, the surface of aluminum anode was activated and dissolved. The so-formed pits expanded rapidly and joined together. The In-riched precipitates bear no relation to the initiation of pits. After long term discharglng,the surface was covered with thick aluminum oxide, upon which there were some deposits of metal zinc and indium, which seem to be responsible for keeping continuous activation and dissolution of alumminum alloy anode.