5A06铝合金搅拌摩擦焊接接头的金属流动规律、显微组织以及腐蚀行为（英文）  

Flow Law,Microstructure and Corrosion Behavior of Friction Stir Welded 5A06 Alloy

作　　者：李亚杰[1] 秦凤明 刘翠荣[1] 吴志生[1] Li Yajie;Qin Fengming;Liu Cuirong;Wu Zhisheng(Taiyuan University of Science and Technology,Taiyuan 030024,China)

机构地区：[1]太原科技大学,山西太原030024

出　　处：《稀有金属材料与工程》2018年第8期2353-2359,共7页Rare Metal Materials and Engineering

基　　金：National Natural Science Foundation of China(51275332)

摘　　要：对5A06铝合金在搅拌摩擦焊接过程中的金属流动规律以及焊后显微组织演变和腐蚀行为进行研究。结果表明:由于受到扭转和漩涡运动的综合作用,前进侧金属被直接卷入搅拌针的螺纹内部,然后被向下挤压进入焊核区。然而,后退侧的金属展现出无序的金属流动模式。通过扫描电子显微镜电子背散射分析发现,搅拌区的晶粒在动态再结晶的作用下发生了明显的细化,再结晶后平均晶粒尺寸约为6μm。对搅拌区的扫描电子显微分析结果表明,β相(Al_3Mg_2)和Al6(Mn,Fe)呈弥散分布,且和母材相比Al6(Mn,Fe)颗粒明显细化。同时,焊缝截面的硬度分布表明焊后5A06铝合金具有软化趋势,最小硬度值(HV)为720 MPa,位于搅拌区和热机影响区的界面处。通过电化学分析和浸泡后的组织观察发现搅拌区的耐腐性明显优于母材,母材的腐蚀电位为–0.725 V,而搅拌区域腐蚀电位升高35 mV。The evolution of metal flow, microstructure and corrosion properties of 5A06 alloy after friction stir welding were studied. Results show that the metal on the advancing side is curled directly into the threads and then is extruded down into the weld nugget zone by complex motions of torsion and swirl. However, the material on the retreating side encounters chaotic flow patterns. The electro backscattering diffraction results indicate that the grains in stir zone are pronouncedly refined by dynamic recrystallization, and the average grain size is about 6 μm. The scanning electron microscope analyses display that β-phase （Al3Mg2） and A16（Mn, Fe） are dispersedly distributed in the stir zone and the A16（Mn, Fe） is smaller than that in base material. The hardness profile is characterized by material softening along the cross-section and the minimum hardness （HV） value of 720 MPa is located in the interface between stirring zone and thermo-mechanically affected zone. It is evident that the stir zone exhibits better corrosion resistance than the base material. The corrosion potential of stir zone is 35 mV larger than that in base material （-0.725 V）.

关 键 词：铝合金 摩擦搅拌焊 流动模式 显微组织 腐蚀行为 

分 类 号：TG453.9[金属学及工艺—焊接]