Friction spot joining (FSpJ)

Friction spot joining (FSpJ) is an alternative joining technology for producing metal-composite joints, patented by and developed at Helmholtz-Zentrum Geesthacht, Germany. This chapter addresses the fundamental scientific and technological aspects of the FSpJ process. During FSpJ process, the friction between the plunging tool and metal sheet generates frictional heat. Heat input is an important parameter in all solid-state joining processes because it governs the temperature in the joining area and therefore the microstructure, local and global properties of the joints. Local mechanical properties in FSpJ are divided into metal properties and composite properties. Microhardness was used to evaluate the local mechanical properties of the joining parts. To evaluate the mechanical performance of FSpJ, a comparison was made with the state-of-the-art adhesive bonding. Adhesive bonding was selected because it is one of the currently available joining techniques in industry for hybrid structures.