Mechanical properties and microstructure analysis of refilling friction stir welding on 2219 aluminum alloy  

作　　者：Peilin LI Zhongfeng XU Chun YU Hao LU Junshan YAO Guoyu CHEN 

机构地区：[1]School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China [2]Shanghai Key Laboratory of Materials Laser Processing and Modificatkon, Shanghai 200240, China [3]Shanghai Aerospace Equipments Manufacture, Shanghai 200240, China

出　　处：《Acta Metallurgica Sinica(English Letters)》2012年第3期225-234,共10页金属学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(Nos.50975176,51035004and51105251)

摘　　要：The 2219 aluminum alloy under refilling friction stir welding （RF-FSW） was investi- gated. The micrographs showed that the bead could be divided into six zones, and the grain size and shape were greatly different in these zones. According to the mi- crostructure analysis, the weld nugget zone and the shoulder stirring zone consisted of equiaxed grains, while the grains in the heat affected zone were seriously coars- ened. It was obvious that bending deformation occurred in the thermo-mechanically affected zone. According to the microhardness analysis, the lowest hardness of the weld was at the thermo-mechanically affected zone, and the microhardness increased with the retraction of the stir-pin. The tensile strength and elongation of the bead were 70% and 80% of the base metal, respectively. The tensile strength was slightly different for the stable stage and the retraction stage, while the elongation decreased in the retraction stage. The mechanical different retraction speed were analyzed, with increasing retraction speed. properties and microstrueture responded to and it showed that the elongation decreasedThe 2219 aluminum alloy under refilling friction stir welding （RF-FSW） was investi- gated. The micrographs showed that the bead could be divided into six zones, and the grain size and shape were greatly different in these zones. According to the mi- crostructure analysis, the weld nugget zone and the shoulder stirring zone consisted of equiaxed grains, while the grains in the heat affected zone were seriously coars- ened. It was obvious that bending deformation occurred in the thermo-mechanically affected zone. According to the microhardness analysis, the lowest hardness of the weld was at the thermo-mechanically affected zone, and the microhardness increased with the retraction of the stir-pin. The tensile strength and elongation of the bead were 70% and 80% of the base metal, respectively. The tensile strength was slightly different for the stable stage and the retraction stage, while the elongation decreased in the retraction stage. The mechanical different retraction speed were analyzed, with increasing retraction speed. properties and microstrueture responded to and it showed that the elongation decreased

关 键 词：Aluminium alloy Friction stir welding Microstructure Mechan- icM property 

分 类 号：TG453.9[金属学及工艺—焊接] V261.34[航空宇航科学与技术—航空宇航制造工程]