微观组织对复合钎焊铝材耐蚀性能的影响  

Effects of Microstructure on Corrosion Resistance of Brazing Aluminum Composite Sheets

作　　者：袁婷[1,2] 张全成 耿飞 彭晓彤[3] 苏朔 何天虎 YUAN Ting;ZHANG Quan-cheng;GENG Fei;PENG Xiao-tong;SU Shuo;HE Tian-hu(Department of Chemistry ＆ Material Engineering,Changshu Institute of Technology,Changshu 215500,China;Jiangsu Laboratory of Recycling and Reuse Technology for Mechanical and Electronic Products,Changshu Institute of Technology,Changshu 215500,China;Jiangsu Alcha Aluminum Co.,Ltd.,Changshu 215532,China)

机构地区：[1]常熟理工学院化学与材料工程学院,江苏常熟215500 [2]江苏省机电产品循环利用技术重点建设实验室,江苏常熟215500 [3]常铝铝业股份有限公司,江苏常熟215532

出　　处：《材料保护》2018年第8期20-25,共6页Materials Protection

基　　金：江苏省高校机电产品循环利用技术重点建设实验室开放课题(KY301201402-16);国家青年科学基金(11405014);常熟市科技发展计划项目(CG201607)资助

摘　　要：目前,针对复合钎焊铝材钎焊前后的组织结构演变有较多研究,但针对组织与耐腐蚀性能之间的关系以及如何改善耐腐蚀性能的相关研究却报道甚少。采用循环酸性海水试验(SWAAT)盐雾腐蚀和电化学腐蚀中的极化曲线、电化学阻抗谱等方法,结合电子探针(EPMA)和能谱仪(EDS)等手段,研究了芯材再结晶组织对复合钎焊铝材耐腐蚀性能的影响。结果表明:在钎焊过程中皮材发生熔化,低熔点Al-Si共晶相沿晶界由皮材向芯材渗入,同时合金元素在皮材及其与芯材交界处发生富集;皮材表面粗大的Al-Si共晶相组织与铝基体间形成腐蚀微电池,引发晶间腐蚀并延伸至芯材内部;钎焊后形成长条状再结晶组织的试样由于扩散的高速通道减少,阻碍Al-Si相渗入及芯材合金元素在皮材晶界的富集行为,降低晶间腐蚀倾向,材料的耐腐蚀性能较好。The influence of core materials＇ recrystallization structure on corrosion resistance of brazing aluminum composite was studied by sea water acetic acid test （SWAAT） and measurement of polarization curves and electrochemical impedance spectroscopy （EIS） , combining with means of electron probe microanalysis （EPMA） and energy spectrum analysis （EDS）. Results showed that the sheath was melted during braze welding process, and the low-melting-point Al-Si eutectic phase infiltrated into the core alloy from sheaths. Meanwhile, the alloying elements gathered at interface of core alloy and sheath. Thus, the Al- Si eutectic phases and aluminum matrix could constitute a great number of small corrosion cells, leading to intergranular corrosion along the grain boundaries and deep into the core. Furthermore, the specimens with band microstructures, which could hinder the inleakage of Al-Si phases and the accumulation of alloying elements, had lower sensitivity to intergrauular corrosion and better corrosion resistance.

关 键 词：复合钎焊铝材 Al-Si共晶相 循环酸性海水试验(SWAAT) 电化学 耐腐蚀性能 

分 类 号：TG454[金属学及工艺—焊接]