Welding3.6
Mechanical behaviour of Friction Spot Welded Joints in 2198-T8 Aluminium Alloy Sheets
Friction spot welding (FSpW) is currently considered as a potential alternative for the replacement of riveted connections in aircraft structures enabling weight savings and production gains. Recently, the 2198-T8 aluminium alloy (Al-Cu-Li system), has received great interest from the aircraft industry due to its low density and superior mechanical properties. Since this alloy has the potential for future applications in aircraft structures, the present work is aimed at the optimization of FSpW process parameters for 3.2mm thick sheets based on the Taguchi method. Furthermore, an analysis of individual effects of process variables on the shear strength of welded joints was also carried out. The tests results have showed that the Taguchi method was effective in determining the parameters leading to highest shear strength of the joint. Lap shear tests on spots with a single spot failed at 131 MPa. High and Low Load Transfer configurations have also been investigated to determine optimum edge distance and pitch. Three spot HLT specimens produced a average maximum shear stress of 354 MPa.