On the double-side probeless friction stir spot welding of AA2198 Al-Li alloy
来源期刊：JOURNAL OF MATERIALS SCIENCE TECHNOLOG2019年第5期
论文作者：Q.Chu W.Y.Li H.L.Hou X.W.Yang A.Vairis C.Wang W.B.Wang
文章页码：784 - 789
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 interface of two sheets. The microhardness profile exhibits a uniform distribution along the thickness direction, in which the hook defect shows the lowest value.
Q.Chu1，W.Y.Li1，H.L.Hou2，X.W.Yang1，A.Vairis1,3，C.Wang2，W.B.Wang2
1. State Key Laboratory of Solidification Processing, Shaanxi Key Laboratory of Friction Welding Technologies, Northwestern Polytechnical University2. Beijing Aeronautical Manufacturing Technology Research Institute3. Mechanical Engineering Department, TEI of Crete
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 interface of two sheets. The microhardness profile exhibits a uniform distribution along the thickness direction, in which the hook defect shows the lowest value.
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