Dissimilar friction stir spot welding of AA2024-T3/AA7075-T6 aluminum alloys under different welding parameters and media  

作　　者：Gui-ju Zhang Cai-yuan Xiao Olatunj Oladimeji Ojo 

机构地区：[1]Key Laboratory of Hunan Province for Efficient Power System and Intelligent Manufacturing,Shaoyang,422000,Hunan,China [2]College of Mechanical and Energy Engineering,Shaoyang University,Shaoyang,422000,Hunan,China [3]Department of Industrial and Production Engineering,Federal University of Technology Akure,Akure,Nigeria

出　　处：《Defence Technology（防务技术）》2021年第2期531-544,共14页Defence Technology

基　　金：Scientific Research Fund of Hunan Provincial Education Department(No.15C1240);Innovation platform open fund Project(No.16K080).

摘　　要：This paper studies the friction stir spot welding of AA2024-T3/AA7075-T6 Al alloys in the ambient and underwater environments by clarifying the nugget features,microstructure,fracture and mechanical properties of the joints.The results show that the water-cooling medium exhibits a significant heat absorption capacity in the AA2024-T3/AA7075-T6 welded joint.Nugget features such as stir zone width,circular imprints,average grain sizes,and angular inter-material hooking are reduced by the watercooling effect in the joints.Narrower whitish(intercalated structures)bands are formed in the underwater joints while Mg2Si and Al2CuMg precipitates are formed in the ambient and the underwater welded joints respectively.An increase in tool rotational speed(600e1400 rpm)and plunge depth(0.1 e0.5 mm)increases the tensile-shear force of the welded AA2024-T3/AA7075-T6 joints in both the ambient and underwater environments.The maximum tensile-shear forces of 5900 N and 6700 N were obtained in the ambient and the underwater welds respectively.

关 键 词：Friction stir spot welding Underwater friction stir spot welding Nugget characterization Microstructure Mechanical properties Fracture 

分 类 号：TG453.9[金属学及工艺—焊接]