On the double-side probeless friction stir spot welding of AA2198 Al-Li alloy  

作　　者：Q.Chu W.Y.Li H.L.Hou X.W.Yang A.Vairis C.Wang W.B.Wang 

机构地区：[1]State Key Laboratory of Solidification Processing, Shaanxi Key Laboratory of Friction Welding Technologies, Northwestern Polytechnical University, Xi'an, 710072, China [2]Beijing Aeronautical Manufacturing Technology Research Institute, Beijing, 100024, China [3]Mechanical Engineering Department,TEI of Crete, Heraklion,Crete,71004, Greece

出　　处：《Journal of Materials Science & Technology》2019年第5期784-789,共6页材料科学技术（英文版）

基　　金：financially supported by the National Natural Science Foundation of China (No. 51574196);the Aeronautical Science Foundation of China (No. 20161125002);the “111 Project” (No. B08040)

摘　　要：Double-side probeless friction stir spot welding (DP-FSSW) of AA2198 alloy was conducted to investigate the microstructure and mechanical properties. Compared with common single-side probeless friction stir spot welding (P-FSSW), the plastic strain during DP-FSSW is nearly symmetrical with respect to the bondline to suppress the extension of hook defect, which is detrimental to the joint mechanical strength. With DP-FSSW, a fully metallurgically bonded region has formed due to severe plastic deformation at high temperatures. Tensile/shear tests show that the joint strength could exceed 8 kN, which is comparable to P-FSSW and refill FSSW, and all fractures happen in a shear failure mode as cracks extend along the in terface of two sheets. The microhard ness profile exhibits a uniform distribution along the thick ness direction, in which the hook defect shows the lowest value.Double-side probeless friction stir spot welding(DP-FSSW) of AA2198 alloy was conducted to investigate the microstructure and mechanical properties. Compared with common single-side probeless friction stir spot welding(P-FSSW), the plastic strain during DP-FSSW is nearly symmetrical with respect to the bondline to suppress the extension of hook defect, which is detrimental to the joint mechanical strength.With DP-FSSW, a fully metallurgically bonded region has formed due to severe plastic deformation at high temperatures. Tensile/shear tests show that the joint strength could exceed 8 kN, which is comparable to P-FSSW and refill FSSW, and all fractures happen in a shear failure mode as cracks extend along the interface of two sheets. The microhardness profile exhibits a uniform distribution along the thickness direction, in which the hook defect shows the lowest value.

关 键 词：FRICTION STIR welding Double-side AL-LI alloy Microstructure Mechanical property 

分 类 号：TG[金属学及工艺]