铝合金牺牲阳极电流效率的损耗分析  

Analysis of Loss in Current Efficiency of Aluminum Alloy Sacrificial Anode in Aqueous Sodium Chloride

作　　者：赵婷婷[1] 冉伟[1] 齐公台[1] 

机构地区：[1]华中科技大学化学系,湖北武汉430074

出　　处：《材料保护》2007年第4期58-60,共3页Materials Protection

摘　　要：用恒电流方法测定了60℃下Al-Zn-In-Sn-Mg-RE和Al-Zn-In-Sn-Si两种铝合金在3%NaCl介质中的腐蚀形貌、电流效率和析氢速率,对铝合金微观组织和主要析出相进行了扫描电镜和能谱分析。结果表明:析氢自腐蚀和机械脱落引起阳极电流效率下降;合金元素以粗大第二相形式析出和阴极性杂质Fe、Si共同导致了铝合金牺牲阳极的析氢和机械损失,影响了阳极性能,但析出相造成的机械损失较大,Fe、Si造成的机械损失相对较小。The current efficiency and hydrogen-evolution rate of aluminum sacrificial anodes made of Al-based alloys Al-Zn-In-Sn-Mg-RE and Al-Zn-In-Sn-Si corroded in 3%NaCl aqueous solution at 60 ℃ were analyzed using constant current method.The morphologies,microstructures,and compositions of the precipitated phase of the corroded Al-alloy sacrificial anodes were analyzed by means of scanning electron microscopy and energy dispersive spectroscopy.The results showed that the decrease in the current efficiency was attributed to both the hydrogen evolution self-corrosion and mechanical detachment as well.The alloying elements were separated out as coarse second phase at the grain boundary,which together with the cathodic impurities Fe and Si led to the hydrogen evolution and mechanical loss of the Al-alloy sacrificial anodes.However,the mechanical loss of the Al-alloy sacrificial anodes was mainly attributed to the segregation phases of the alloying elements but not the cathodic impurities Fe or Si.

关 键 词：铝合金 牺牲阳极 电流效率 析氢自腐蚀 机械脱落 

分 类 号：TG178[金属学及工艺—金属表面处理] TG146.21[金属学及工艺—金属学]