AA5052铝合金/AZ31B镁合金搅拌摩擦焊接头的腐蚀行为研究  

Study on Corrosion Behavior of Friction Stir Welded Joints of AA5052 Aluminum/AZ31B Magnesium Alloys

作　　者：蔡达 王立世 胡心彬 CAI Da;WANG Lishi;HU Xinbin(School of Materials and Chemical Engineering,Hubei University of Technology,Wuhan 430068,China;Hubei Provincial Key Laboratory of Green Materials for Light Industry,Wuhan 430068,China)

机构地区：[1]湖北工业大学材料与化学工程学院,武汉430068 [2]绿色轻工材料湖北省重点实验室,武汉430068

出　　处：《材料导报》2023年第4期147-153,共7页Materials Reports

基　　金：中央引导地方科技发展专项(2019ZYYD015)。

摘　　要：采用搅拌摩擦焊的方法得到了外观成形良好的Al合金/Mg合金接头。为了研究其腐蚀行为和腐蚀机理,在分析焊接接头显微组织的基础上,采用中性盐雾腐蚀试验和电化学测试的方法对其腐蚀行为进行监测和分析,并对焊接接头的腐蚀失重进行了分析研究。结果表明,铝镁金属间化合相和镁合金中的β相在搅拌区和热力影响区中分布的不均匀性,以及区域晶粒大小的差异,导致搅拌区和热力影响区形成微区原电池的倾向不同,从而表现出腐蚀形貌和腐蚀行为的差异。电偶腐蚀的发生导致焊接接头的腐蚀电流密度较高,耐腐蚀性能不及母材。在整个中性盐雾腐蚀过程中,腐蚀失重逐渐增加,腐蚀速率呈现出先上升后下降的趋势。In this work,the friction stir welding was used to weld the Al/Mg alloy joints with good appearance.In order to study the corrosion behavior and corrosion mechanism,based on the analysis of the microstructure of the welded joint,the corrosion behavior of the welded joint was monitored and analyzed by the neutral salt spray corrosion test and electrochemical test,and the corrosion weight loss of the welded joint was analyzed.The results show that the inhomogeneity of the distribution of Al-Mg intermetallic compound andβphase in magnesium alloy in the stir zone and the thermo-mechanically affected zone,as well as the difference in the grain size of the region,leads to the difference in the tendency of forming primary batteries in the micro-plot of stirring zone and thermo-mechanically affected zone,thus showing the difference in corrosion morphology and corrosion behavior.The occurrence of galvanic corrosion leads to high corrosion current density in the welded joint,and the corrosion resistance is inferior to the base metal.During the whole neutral salt spray corrosion process,the mass loss is gradually increased,and the corrosion rate shows a downward trend after the first rise.

关 键 词：铝合金 镁合金 搅拌摩擦焊 异种接头 腐蚀行为 

分 类 号：TG172.2[金属学及工艺—金属表面处理]