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

• 来源期刊: 材料科学技术（英文版）
• 年，卷（期）: 2019,（5）
• 页码范围: 784-789
• 页数: 6页
• 语种: 英文

摘要

Double-side probeless friction stir spot welding (DP-FSSW) ofAA2198 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.