Friction Stir Blind Riveting for Dissimilar Cast MG AM60 and Al Alloy Sheets

A new one-sided joining method, friction stirring blind riveting (FSBR) was successfully implemented to form lap-shear joints for dissimilar metals from pairs of 3.05mm thick cast Mg AM60, rolled 1.5mm thick Al AA6022 and extruded 3.15mm thick Al AA6082 specimens. The concept of this process is riveting the two workpieces with reduced force under frictional heat and fastening the workpieces through blind riveting once the rivet is fully inserted. In this research the process was experimentally analyzed and optimized for four joint combinations. It was demonstrated that switching the positions of Mg and Al alloy specimens has a significant effect on the process window and maximum tensile load of the joints. Three quality issues of the FSBR joints were observed and discussed. The mechanisms associated with joint strength were discussed and explain the effects of FSBR process, material matching and sheet position on the joint tensile strength.