不同稀土含量的铝合金牺牲阳极的显微组织研究

THE MICROSTRUCTURE OF ALUMINUM ALLOY SACRIFICIAL ANODE CONTAINING DIFFERENT RE CONTENTS

浇铸了４种不同ＲＥ含量的Ａｌ－Ｚｎ－Ｉｎ－Ｓｎ－Ｍｇ合金牺牲阳极．利用金相显微镜、扫描电镜（ＳＥＭ）和能谱分析，确定了４种合金的晶粒尺寸、偏析相数量及其成分．结果表明：随着ＲＥ含量的增加，铝合金的晶粒变小，偏析相的数量先增加后减少；偏析相主要为晶界析出物和弥散相；ＲＥ含量不同时，晶界析出物不同；细化阳极晶粒最佳ＲＥ含量０．５％，０．３％ＲＥ时阳极偏析相数量最多．

Four kinds of aluminum alloy anodes containing different RE contents were cast. Microscope and scanning electron microscope (SEM) were used for analyzing their microstructure such as grain size of the amount segregative phase and composition of aluminium anodes. The results show: (1)With increasing RE content, the grain size of aluminum alloys becomes small, while the amount of segregative phase increases followed by reducing. (2)In aluminum alloy with low RE content, their dendrite becomes large and there are many a few segregative phases. On the other hand, with high RE content the dendrite is small and there are a few segregative phases. (3)If RE content in aluminum alloys is more than 0.5%, the compositions of segregative phases are different. In the case,both of the segregation phase with high Sn content and the segregation phase with high RE content may appear.